The fungi which cause plant disease

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ALBERT R. MANN
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THE FUNGI WHICH CAUSE PLANT DISEASE

THE MACMILLAN COMPANY

NEW YORK - BOSTON - CHICAGO - DALLAS
ATLANTA -« SAN FRANCISCO

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TORONTO

THE FUNGI WHICH CAUSE
PLANT DISEASE

BY
F. L. STEVENS, Pu. D.

PROFESSOR OF VEGETABLE PATHOLOGY AND DEAN, COLLEGE OF
AGRICULTURE AND MECHANIC ARTS, MAYAGUEZ, PORTO
RICO. FORMERLY OF THE NORTH CAROLINA
COLLEGE OF AGRICULTURE ALSO FORMERLY
PRESIDENT OF THE AMERICAN PHY-
TOPATHOLOGICAL SOCIETY

Nem York
THE MACMILLAN COMPANY
1913

All rights reserved

Coryaicsr, 1913
By THE MACMILLAN COMPANY
Set up and electrotyped. Published November, 1913

TO
MY WIFE

ADELINE CHAPMAN STEVENS

IN ACKNOWLEDGMENT
OF
HELP, ENCOURAGEMENT
AND INSPIRATION

PREFACE

This volume is intended to introduce to the student the more
important cryptogamic parasites affecting economic plants in the
United States, with sufficient keys and descriptions to enable
their identification. Technical description of each division, order,
family, genus and species when important is given unless the
essential characters are to be clearly inferred from preceding keys
or text. Gross descriptions of the host as diseased, i. e., of the
disease itself, have been avoided since such are to be found in
“Diseases of Economic Plants.” Effort has been made to avoid
duplication of matter contained in that volume. Abundant
citations to the more important papers are given, sufficient, it is
believed, to put the student in touch with the literature of the
subject. :

While many parasites not yet known in the United States are
briefly mentioned, especially the more important ones or those
which are likely to invade America, no attempt has been made to
list all of these. Non-parasitic groups closely related to those that
are parasitic have been introduced in the keys merely to give a
larger perspective to the student.

Effort has been made to give at least one illustration of each
genus that is of importance in the United States.

The author is indebted for descriptions, keys, etc., to the
various standard works. Those which have been drawn upon
most largely are Saccardo’s Sylloge Fungorum, Die Natiirlichen
Pflanzenfamilien of Engler & Prantl, Clinton’s Ustilaginales of
North America, Clement’s Genera of Fungi, and Minnesota
Mushrooms, Plowright’s British Uredinee and Ustilaginee, Ar-
thur and Murrill each in North American Flora.

The author wishes also to express thanks for suggestions and
criticism of the manuscript to T. H. Macbride, who read the por-
tion on Myxomycetes; J. J. Davis, Phycomycetes; L. R. Jones

vu

viii PREFACE

and T. J. Burrill, Bacteria; G. M. Reed, Perisporiales; G. P. Clin-
ton, Ustilaginales; J. L. Sheldon, Ascomycetes in part; D. Red-
dick, Ascomycetes in part; J. C. Arthur, Uredinales; F. D. Heald,
Fungi Imperfecti in part; F. C. Stewart, Fungi Imperfecti in part;
H. Metcalf, Basidiomycetes in part; to Mrs. Flora W. Patter-
son for aid in securing descriptions otherwise unobtainable; to
Dr. Marshall Avery Howe for assistance with the glossary; to
Messrs. Norton, Rosenkranz and Fawcett, for aid in proof-
reading and in preparation of the manuscript, though no re-
sponsibility for error attaches to those who have so kindly
aided.

It is probable, owing to the present unsatisfactory condition of
taxonomy of the fungi, loose and imperfect description of species,
disregard of generic limitation, lack of knowledge regarding the
limits of specific variation, influence of environment, biologic host
relations, etc., that many of the species treated in the text are
untenable. The author has, however, attempted so far as possible
to reflect the facts as they appear in the light of present knowledge
and has deenied it more useful to err on the side of conservatism
than to attempt to reduce the apparent number of species by con-
solidation without full and complete evidence as to the real identity
of the species in question. °

F. L. Srevens.

Mayactez, Porto Rico.

CONTENTS

PAGE
INTRODUCTION. .......0.0.00..0 022 cee cee eee ee ee Ged et 1
Division I, MyXOMYCETES....................--. Zeon 20
Division II, SCHIZOMYCETES..........0.000000 000000 e cues 13
BisuioGRAPHY OF INTRODUCTION, MYXOMYCETES AND
SCHIZOMYCETES.......0..0.0000050 0 cece eee eee 53
Division III, EuMyceres.............00 6.2... 12.0. . 59
CLASS PHYCOMYCETES. « i.6 520000 usu ee whee .... 65
BIBLIOGRAPHY OF PHYCOMYCETES...... ..... .... 109
Cuass ASCOMYCETES. ...........22000025200 fees .. 118
BIBLIOGRAPHY OF ASCOMYCETES......... ....... .. 288
Cuass BASIDIOMYCETES. ............. toe, salseed gion 298
BIBLIOGRAPHY OF BASIDIOMYCETES. .... ...... .. 466
FuNGI IMPERFECTI......00.000000 000000 cee eee ... 475
BIBLIOGRAPHY OF FUNGI IMPERFECTI.. .... .... 666
BIBLIOGRAPHY OF BOOKS AND PERIODICALS.... .........-. 678
GLOSSARY. Snes ete nae ences. Vesetty. Tehyhduats 681
UND Bi ck Wc eecteee here ator ae che Meena ep ark ie Slice ae ee oe 697

THE FUNGI WHICH CAUSE PLANT DISEASE

INTRODUCTION

The principal non-flowering vegetable parasites which cause
plant diseases belong to three divisions: the Slime Molds (Myxo-
mycetes); the Bacteria (Schizomycetes); and the True Fungi
(Eumycetes including the Phycomycetes). The term fungi, in
the broad sense, is often used to include all three of these divisions.
All are devoid of chlorophyll and therefore all differ from the green
plants in the essential ways which result from this deficiency.
Transpiration, respiration, and true assimilation are the same as
with the green plants, but photosynthesis or starch manufacture
cannot be accomplished by them. Sunlight being thus useless to

- them directly they can live in the dark as well as the light. Having
no ability to elaborate their own foods from inorganic matter
these organisms are limited to such nutriment as they can obtain
from plants or animals which have elaborated it; that is, they must
have organic foods for their sustenance.

The fungi have acquired various food habits and adapted them-
selves to different methods of nutrition. Some are nearly om-
nivorous and can subsist upon almost any decaying tissue or upon
soils or solutions rich with organic debris. Others thrive only
upon special substances, as for example, some particular plant or
animal, the host, perhaps only upon some particular part of that
plant or animal. The organisms that prey upon living things are
called parasites. Those living upon dead things are sapro-
phytes. No hard and fast line can be drawn between these two
classes. An organism which is usually a saprophyte may live
upon a dead member of some plant, gradually encroach upon the
still living part and thus become partially a parasite. Again there
are times in the history of a plant when life ebbs so low that it is
difficult to tell the living from the dead. The pulp of the apple

1

2 THE FUNGI WHICH CAUSE PLANT DISEASE

when ripe, a resting seed, the cells of the potato tuber in winter,
are undoubtedly alive, yet their activity is so little that many
organisms can gain a foothold upon these stages of the plant
that cannot do so at more vigorous periods of their exist-
ence.

Tubeuf *” ranks as hemi-parasites those organisms that usually
are parasites, but may sometimes become saprophytic, and as
hemi-saprophytes such as are usually parasitic, but may excep-
tionally become saprophytic. These distinctions are of little
import, other than to bring out clearly that each species has its
own limits as to food requirements.

It is hardly to be thought that these parasites and saprophytes
have always been dependent organisms. The true fungi for ex-
ample are best to be regarded as degraded descendants of alge,
in which ancestors they once possessed chlorophyll and could
prepare their own food from mineral matter by the aid of sun-
light.

No discussion of the general metabolic processes of the fungi is
here necessary further than to indicate that among the products
of their activity there are various excretions and secretions, which
bear important relations to parasitism. Thus certain fungi grow-
ing in artificial culture produce enzymes or organic ferments
capable of softening and dissolving cellulose, also toxins, poisons
which are capable of killing the cells of the host plant. Such
enzymes and toxins are numerous and their bearing upon par-
asitism is obvious. They enable the parasite to kill adjacent cells
of the host and then to effect an entrance through the cell walls
to the protoplasm and other nutrients contained within the
cell.

The presence of the parasite, or secretions produced by it, often
calls forth. abnormal growth responses from the host. These take
very diverse forms, either the undergrowth or overgrowth, hyper-
trophy, of single cells or tissues, or even the excessive development
of large plant parts as in the case of the witches’ brooms, and the
‘double flowering” of the dewberry.

The probable relations of the groups under consideration to the
other members of the Thallophyta are suggested in the following
scheme.”

THE FUNGI WHICH CAUSE PLANT DISEASE 3
TERA, Schizomycetes.
YANOPHYCES, Blue-green Alge.

Myxomycetss, Slime Fungi.

Fresno, Dinoflagellates.

ONJUGAT#, Conjugates.
IATOME.
omens FT ETEROCONTE.

HLOROPHYCES, Green Alge.

HARACE#, Stoneworts.
Le cnoereun, Red Alge.
EEUMYCETES, Fungi.
‘PHYCOMYCETES, Alga-like Fungi.
PHEOPHYCE, Brown Alge.

Key to the three Divisions important as plant parasites:

Vegetative body a multinucleate naked plasmodium
Division I. Myxomycetes, p. 5.
Vegetative body a single-walled cell, nucleus absent or not of the
form typical in the other fungi, reproduction by fission (by conidia
in a few non-parasitic forms)... Division II. Schizomycetes, p. 13.
Not as above: Vegetative body usually filamentous, reproduction by
various means................ Division III. Eumycetes, p. 59.

DIVISION I

MYXOMYCETES, SLIME MOLDS, SLIME
FUNGI" (p. 3)

These are the lowest organisms considered by the botanist, and
partake so much of the nature of both animals and plants that
their position has long been debated. Their affinities are with the
lowest living things, on the boundary between the animal and the
vegetable kingdom, and sometimes more attention is accorded
them by the zodlogist than by the botanist.

The distinctive character of this group is that the vegetative
condition consists either of distinct amceboid cells or of a mass of
naked protoplasm, the plasmodium, composed of numerous cell
units, each unwalled. The plasmodia, at the completion of the
free vegetative stage, produce numerous walled spores either free
or in sporangia of various forms. The spores upon germination
produce either zodspores or amoeboid bodies which multiply and
unite to form either new plasmodia or pseudoplasmodia.

The slime molds consist of three orders:

¢

Key to Orpers or Myxomycetes

PATASICIG a2 shes: onsen 2A SP klne > pee Re eS 1. Plasmodiophorales, p. 5.
Saprophytic

Vegetative phase of free‘amcebe ..... 2. Acrasiales

Vegetative phase plasmodial......... 3. Myxogastrales, p. 9.

The Acrasiales contain some five genera and ten species purely
saprophytic.
Plasmodiophorales
Intracellular parasites; vegetative stage plasmodial; spores
formed by the simultaneous breaking up of the plasmodium into

an indefinite number of independent cells.
5

6 THE FUNGI WHICH CAUSE PLANT DISEASE

The Plasmodiophorales appear to include all of the true para-
sites of the Myxomycetes.

Key To GENERA orf Plasmodiophorales

Spores free, spherical................ 1. Plasmodiophora, p. 6.
. Spores united into groups
Spores in groups of four............ 2. Tetramyxa, p. 8.

Spores in larger groups
Spores forming a hollow sphere.... 3. Sorosphera, p. 8.
Spores forming a spongy spore-ball 4. Spongospora, p. 8.

Plasmodiophora Woronin

This genus is parasitic in the living parenchyma of the roots
of plants, the plasmodia filling the cells and causing galls at
the point of attack. There are three species of the genus in
Europe and America.

P. brassicze Wor.1® 200-203 208 has long been known as a parasite
on the crucifers generally and recent work indicates that other
families, as the Umbellifere and cucurbs, are also susceptible.

The parasitised cells especially, and the adjacent cells as well,
are stimulated to enormous overgrowth; this hypertrophy result-
ing in a characteristic root “clubbing.”

Study of diseased sections shows that the medullary rays and
cortex are abnormally thick (hypertrophy and hyperplasia) and
many of their cells are parasitized. Sclerenchyma cells are sup-
pressed by the parasite and the xylem is reduced and phloem in-
creased proportionately. The amount of stored starch is much
less than in normal tissues.

Infection does not appear to pass from cell to cell but groups of
diseased cells are thought to arise from repeated division of a cell
after its infection.

Tn the enlarged host cells the protoplasm appears abnormally
dense and fine grained. Eventually the whole lumen of the cell is
occupied by the crowded, amceboid, individuals, each uninucleate
and unwalled, and still distinct from the other. These individuals
later fuse into a plasmodium the nuclei of which enlarge and un-
dergo simultaneous mitotic division. Still later the mass divides
into uninuclear segments each of which matures to a spore 1.6 »
in diameter, covered by a thin, smooth, colorless membrane.

THE FUNGI WHICH CAUSE PLANT DISEASE 7

The decay of the host liberates the spores in the soil. Their
germination may be readily studied upon a microscope slide
where in from five to twenty-four hours uninucleate zodspores
are produced. The zodspores are differentiated into an inner

ice: i icellular parasite; 5, later
_1.—P. brassicee: 3, cabbage cells occupied by the unicel 5, lat
nies parasite. many-nucleate; 10, host cell full of spores; 11, germinating
spores. After Lotsy.

granular part and an outer hyaline part, the hyaloplasm, which
may extend to form pseudopodia, thus giving the cell an ameeboid
movement in addition to that due to the single long cilium. In-
fection by these swarm spores is supposed to occur through the
root hairs though the mode of primary infection is not definitely

8 THE FUNGI WHICH CAUSE PLANT DISEASE

known. Seedlings raised in soil inoculated with chopped roots
bearing the disease become badly diseased as do also seedlings
upon which infected water is poured.

P. humili Kirk is mentioned by Kirk’ as the cause of club
root of hops in New Zealand.

P. vitis Viala & Sauvageau; ® P. californica Viala & Sauvageau; ?®
P. orchidis Massee and P. tomato Abbey " have been reported
as the causes of serious diseases but their relation to the diseases
and even their identity as actual organisms is seriously ques-
tioned.17"4

Tetramyxa Goebel grows upon water plants, notably Ruppia.’

Sorosphera Schroter (p. 6)

Parasitic in the parenchyma of living plants; spores elliptic-
wedge shaped, forming a hollow, spherical spore ball.

One species is found upon Veronica;* a second species has been
reported upon tea.

S. graminis Schwartz is reported by Schwartz ¥’ on the roots
of Poa and other grasses where it caused nodules much resembling
those of nematodes.

Spongospora Brunchorst (p. 6)

Similar’ to Sorosphera but the spores forming a spore ball
with open reticulations.

S. subterranea (Wallr.) Lag.’” causes the powdery scab of
potatoes in Great Britain, Europe and South America. It has
been closely studied by Osborne who shows it to appear first in
the tuber cells as a uninucleate myxamceba which ultimately
develops into a multinucleate amceboid plasmodium.

Sorolpidium Nemec is a new genus with the species.

S. betee Nemec which is on beets.

Several little known genera, kin to the above, attack alge,
fungi, pollen, ete.

Pseudomonas radicicola, the legume tubercle organism has been
by some placed in this order under the name Phytomyxa legumi-
nosarum.

THE FUNGI WHICH CAUSE PLANT DISEASE 9

Myxogastrales (p. 5)

This order comprises some forty-seven genera and four hun-
dred species of great variety and beauty. The plasmodium,
which varies from a millimeter or less
to several decimeters in diameter, pro-
duces either flat encrusted masses of
spores, ethalia, or develops spores in
sporangia which show some superficial
resemblance to very small puffballs,
Fig. 2. The interior of the sporan- Lact
gium is often permeated by a thread- Spe REE pe nt Sn

like structure, the capillitium. They tals. After Macbride.

are not parasites but occasionally injure plants by overgrowing
them.

i P

Key To Famiuies or Myxogastrales

Spores not enclosed in a sporangium, borne
externally upon the fruiting bodies.... 1. Ceratiomyxacee.
Spores enclosed in a sporangium
Capillitium wanting, or very poorly de-
veloped
Periderm of uniform thickness, rup-
turing irregularly ................ 2. Liceacee.
Periderm of unequal thickness
Periderm with a subapical thin line,
opening by an operculum....... 3. Orcadellacee.
Periderm unequally thick above, the
thin portions evanescent, leaving
a network formed by the thicker
portions. .... 2. cece eee eee ees 4. Cribrariacez.
Capillitium well developed
Caleareous deposits absent, or rarely
present in the periderm
Capillitium of hollow, usually sculp-
tured threads; spores light colored 5. Trichiaces.
Capillitium of solid, smooth and
usually much branched threads:
spores dark colored
Fruiting bodies zthalioid or in-

10 THE FUNGI WHICH CAUSE PLANT DISEASE

definite, walls poorly defined,
fraying out into a pseudo-
capillitium................. 6. Reticulariacez.
Sporangia definite, true capilli-
tium more or less prominent 7. Brefeldiacez.
Fruiting bodies separate sporangia
with columella and abundant
capillitium. ...............-.- 8. Stemonitacee.
Calcareous deposits present
Capillitium not calcareous
Capillitium simple ............. 9. Didymiacee, p. 10.
Capillitium more intricate. ...... 10. Spumariacea, p. 11.
Fructification calcareous throughout 11. Physaracee, p. 11.

Didymiacee
Fructification of separate sporangia or plasmodiocarps, periderm
simple or double, the outer calcareous; columella present or ab-
sent; capillitial threads thin, colorless or violet, arising from the
base of the sporangium or passing from the columella to the peri-
derm, usually without calcareous deposits, which if present are
very small crystals; spores in mass black, spore walls violet.

Key to Genrra or Didymiacez

Calcareous deposits in the form of stellate crys-
tals, frosting the surface.................... 1. Didymium, p. 10.
Caleareous deposits not stellate,
Calcareous deposits forming a superficial crust 2. Diderma.
Calcareous deposits forming large superficial
SCRIEB HS, So nc uke aihe Boe aba ees way ke oe 3. Lepidoderma.

Didymium Schréter

Sporangia distinct, stipitate, sessile or even plasmodiocarpous,
never zthalioid; the peridium thin, irregular in dehiscence, cov-
ered with a more or less dense coating of calcareous crystals;
columella more frequently present; capillitium of delicate threads,
simple or sparingly branched, extending from the columella to the
peridial wall.

D. dedalium. B. & Br. is occasionally injurious to melons in
culture.”

THE FUNGI WHICH CAUSE PLANT DISEASE 11

Spumariacee (p. 10)

Sporangia separate or ethalioid; calcarious deposit in the peri-
derm or columella, never in the capillitium; capillitium radiating
from various points of the columella, branching and anastomosing
to form a network, the ultimate branchlets of which support the
periderm.

Key to GENERA oF Spumariacee

Fructification of ordinary sporangia............. 1. Diachea.
Fructification ethalioid ....................0.. 2. Spumaria, p. 11.

Spumaria Persoon

Fructification ethalioid, consisting generally of large cushion-
shaped masses covered without by a white foam-like crust; within,
composed of numerous tubular sporangia, developed from a com-
mon hypothallus, irregularly branched, contorted and more or less
confluent; the peridial wall thin, delicate, frosted with stellate
lime crystals, which mark in section the boundaries of the several
sporangia; capillitium of delicate threads, generally only slightly
branched, terminating in the sporangial wall, marked with oc-
casional swellings or thickenings.

S. alba (Bul.) D. C. Like all other members of the order
the present species is not a parasite but its wthalia are fre-
quently produced upon grass, strawberries ?! and other plants in
such abundance as to cause more or less serious injury. The
sporangia are fused into a large ethalium which is white or cream-
colored, from 1 to 7 cm. long and half as thick.

Physaracee (p. 10)

Key To GENERA OF Physaracee

Fructification xthalioid ..............---.--- 1. Fuligo, p. 12.
Fructification plasmodiocarpous or of distinct
sporangia
Peridium without lime
Plasmodiocarpous ...........--+0++++e0es 2. Cienkowskia.
Sporangia distinct ............+.---0-0-- 3. Leocarpus.

Peridium calcareous, more or less throughout
Capillitium calcareous throughout... ..... 4. Badhamia.

12 THE FUNGI WHICH CAUSE PLANT DISEASE

Capillitium in part hyaline
Sporangium vaselike, or more or less tubu-

lar
Opening irregularly. ............... 5. Physarella.
Opening by alid.............. ..... 6. Craterium.

Sporangia various, dehiscence irregular
Capillitium evenly branched; the calca-
reous nodes small, fusiform.... .... 7. Tilmadoche.
Capillitium intricate... ... ee eae 8. Physarum, p. 12.

The species of Fuligo produce very large yellowish plasmodia
which change to yellowish or brownish zthalia. Some are credited
with damage similar to that of the preceding species.””

Physarum Persoon

Sporangia plasmodiocarpous, ethalioid or distinct; the peridium
usually simple, sometimes double, irregularly dehiscent, more or
less definitely calcareous; capillitium a uni-
form irregular net, dilated and calcareous at
the nodes, adherent on all sides to the
peridial wall.

P. cinereum (Batsch), Pers., the species
most commonly reported as injurious, forms
its tiny sessile, gray sporangia in great num-
hers on living plants, ™ often smother-
ing them. The peridium is lime charged as

Fic. 3.—Physarum perros
sporangium. After are also the nodes of the capillitium. The

alan spores are brown or violet, and warty.

P. bivalve F. has been noted as injuring young bean plants.”

Dendrophagus globosus Toumey was reported by Toumey ”8
as the probable cause of crown gall, but such relation is doubt-
ful (p. 36). It is said to be closely related to Physarum.

DIVISION II
BACTERIA, SCHIZOMYCETES * **“° (p._3)
Bacteria are extremely minute, unicellular organisms, which in

outline present three primary forms each of great simplicity,
namely the spheres (cocci),

the straight rods (bacteria), ie ee
the curved rods (spirilli). 0a Sh G

In addition to these forms 20 jF

: : oD? z
which comprise the vast 4
majority of known species QD aS) —)
of bacteria there are also 9 oe” —

bacteria consisting of fila- Fie. 4—The three type forms of bacteria;
mentous bodies, either sim- % SPheresi ©. rods; c, spirals. After Conn.
ple or branched, attached or free. In both structure and phys-
iology bacteria are allied to the vegetable kingdom and in it
most closely to the blue green alge.

Bacteria are inconceivably small. Most of the spherical bacteria
fall within the limits of from 0.5 to 1.5 » in diameter. Among
the rod and curved bacteria the length in most species is between
1 and 1.5 yu, the diameter between 0.5 and 1 ». Among the
largest species is B. megatherium, 2.5 x 10 »; Clostridium butyri-
cum, 3 x 10 y; and Spirillum volutans, 13 to 50 » long. Among
the smallest is Spirillum parvum 0.1-0.3 » in diameter and Pseudo-
monas indigofera 0.06 x 0.18 u.

It is practically impossible to conceive these dimensions. An
illustration may aid the imagination. The paper on which these

words are printed is about 87.5 u thick. It

= would therefore take about 200 bacteria of ordi-

Fic. 5.—This dot is nary size or 400 moderately small or 20 very

Imm. in diameter. }arge ones placed end to end to equal in length

the thickness of this paper. It would take 1571 ordinary bacteria

(1 x 2 yz) end to end to reach around the circumference of a dot
13

14 THE FUNGI WHICH CAUSE PLANT DISEASE

1 mm. in diameter. (Fig. 5.) 500 to reach across it; and 392,700
placed side by side or 785,400 if placed on end to cover its area, and
about 500,000,000 to fill a cube the edge of which is 1 millimeter,
making no allowance for lost space of the interstices. Considerably
more than 500,000,000,000 bacteria of this size would find room
enough to move about in a space of one cubic centimeter.

The typical mode of increase among bacteria—the only mode
except among the sheath bacteria—is by fission or direct divi-
sion of one cell, the mother cell, into two, the daughter cells.
Fig. 6. The rapidity with which fission can proceed depends of
course upon conditions of environment, ranging from no growth
at all, due to cold, lack of nutriment, presence of inhibiting sub-
stance, to a maximum that varies with the species. For bacteria

VYODOG

Fic. 6.—Diagram illustrating the fission of bacteria, bacilli and cocci.
After Novy.

in general under very favorable surroundings, with proper tem-
perature and abundance of food, from 20 to 40 minutes may be
reckoned as a generation. In 24 hours, with the divisions once
each hour, the progeny of one germ will be 16,777,216; with
divisions each 30 minutes it will be (16,777,216)?

If cell division be in one direction only and the resulting daugh-
ter cells remain undisturbed, a thread-like row results. If cell
division be in two planes, and the resulting cells adhere in groups,
tablets of 8, 16, and 64 will occur frequently. If the division be
in three planes and their cells adhere, packets result.

The structure of the bacterium cell owing to its minuteness
is yet very incompletely known. The most enduring portion of.
the vegetative cell is the cell wall. This is surrounded by a layer,
the capsule and bears the flagella. The number of the flagella
and their position varies in different species. Some species have
none, some one, two, or many. They may be at the ends, polar,

THE FUNGI WHICH CAUSE PLANT DISEASE 15

or scattered over the whole surface, diffuse or peritrichiate.
They are the organs of locomotion. Within the wall is the pro-
toplast consisting of a peripheral layer, inner strands, imbedded
granules and vacuoles bearing cell sap. The existence of a nucleus
comparable to that in higher plants is a much controverted point.
Spores: Typically a bacterial spore consists of a highly refractive,
ovoid, walled body within the mother cell. This body possesses
high resistance to ordinary stains, a great tenacity against de-
colorizing if it be once
stained, a higher resist-
ance against adverse tem- «777g
peratures and adverse
conditions generally than

do vegetative cells, and

finally the ability to ger- <@j>= y % 4 9
minate and thus aid in ED

perpetuating the species. “a S

While the absolute num- Fic. 7.—Spores of bacteria showing their position
ber of bacterial species within the cells. After Frost & McCampbell.
that form spores is large, comparatively they are few. They are
most frequently met among the rod forms, and are rare among
the spirilla and cocci. None are known among the important
plant pathogens.

In the simplest cases of spore formation, the protoplasm be-
comes more dense in some part of the mother cell, the remaining
protoplasm of the cell is drawn around the denser mass, and the
whole resulting dense region becomes
enclosed within a special wall. Usually
in this process nearly all the protoplasm
of the mother cell, the sporangium, is
used. The mother cells .during spore
formation may remain of the normal
Fic. 8.—Spore formation in vegetative size and shape; they may

bacteria. After Fischer. take on (B. subtilis) or abandon (B.
megatherium) the habit of thread formation. Bacteria of many
species become swollen at the point where the spore develops,
Figs. 7 and 9; be this in one end (Vibrio rugula) or in the middle
(B. inflatus). The swelling at the end is very common, giving rise

16 THE FUNGI WHICH CAUSE PLANT DISEASE

to the peculiar and characteristic form known as “ Nail Head” or
“Drum Stick” bacteria. In nearly all species of the Eubacteria
the spores are solitary. ,

There are three modes of spore germination. The most com-
mon, polar germination, consists in a rupture of one pole of the
spore and the development of a normal vegetative cell through
the opening. The second mode, equatorial, Fig. 9, consists in a
rupture in the side instead of the end of the spore. The third mode,

Fie. 9.—Spores of bacteria, showing bispored cells, spore formation and spore
germination. After Prazmowski, De Bary and Koch.

absorption, consists in a direct development of the whcle spore
into a vegetative cell. In suitable environment germination may
occur immediately after spore formation; if conditions be unsuit-
able it may be delayed for many years.

Under certain conditions most bacteria undergo abnormal
changes in form becoming elongated, branched, swollen, bulged,
curved, or variously, usually irregularly, distorted. Such are
termed involution forms. They are in most cases due to unfavor-
able conditions of temperature and nutriment, and the bacteria
resume their normal form when again in normal environment.

The branched forms found in root tubercles after the period of
luxuriant growth has passed, and the branched thread-like growth
of the bacterium of human tuberculosis upon artificial media, are
by many regarded as involution forms.

THE FUNGI WHICH CAUSE PLANT DISEASE 17

Constancy of Species. Bacteria in nature and under artificial
conditions remain true to species. There may be variation from
generation to generation as among all other plants or animals of
the world, and by the slow process of evolution, a species may in
many generations become modified, leading eventually to new
races, varieties, and possibly species. That one species can change
directly and suddenly to another, much less a species of one genus
into a species of another genus, is not to be credited. Marked
variation is brought about in many species by change in tempera-
ture, food, oxygen supply, etc., changes in size, form, sporulation,
flagellation, virulence, chromogenesis, fermentative power, group-
ing, etc. These changes belong to the life cycle of the species and
occur as reactions to the environment.

Bacteria were discovered by Loewenhoek in 1683. That they
do not originate spontaneously was shown by Pasteur in 1860-4.
The first disease producing bacteria were recognized in anthrax by
Pollander & Davaine in 1849; and the first definite proof that
bacteria actually cause animal disease was made by Koch with
anthrax in 1875-1878. The first plant disease to be definitely as-
cribed to bacteria was the pear blight by Burrill in 1879. The
invention of the cotton plug, Schroeder & Dusch, 1853, the gela-
tine method of plating for the isolation of species, Koch, 1881,
and the use of stains, Weigert, 1875, were practically necessary
prerequisites to any considerable advance in bacteriology. For
long it was contended, especially by European bacteriologists,
that bacteria do not cause plant diseases but most convincing
proof to the contrary was adduced by E. F. Smith.

Entrance to the host plant is made in various ways, very often
through wounds, particularly wounds caused by insects, through
roots, stomata, water pores, through delicate tissues as blossoms,
etc. Once in the tissue, bacteria may migrate rapidly by means
of the vessels, intercellular spaces or more slowly through cavities
dissolved by the aid of enzymes.

Classification. In all there are some thirty-six well recognized
genera embracing twelve hundred or thirteen hundred purported
species of bacteria. This number will doubtless be greatly de-
creased when the organisms have been well studied, by finding
that many so-called species are not really distinct. The number

18 THE FUNGI WHICH CAUSE PLANT DISEASE

will also of course receive many additions of forms not as yet
known.

No system of classification can yet be said to have general
acceptance and all classifications now in vogue will undoubtedly
undergo minor changes and perhaps changes in fundamental
conception.

The system of Migula™ meets probably with most favor.
With the omission of genera of little import pathologically, and
with the introduction of the order Myxobacteriales, it is as follows:

SCHIZOMYCETES (p. 3)

Fission plants, without phycochrome, dividing in one, two or
three directions of space. Reproduction by vegetative multiplica-
tion. Resting stages, endospores, exist in many species. Motility
by means of flagella in many genera.

Key To ORDERS, FAMILIES, AND GENERA OF Schizomycetes

POM oes tievsidless ite ied Se Saree ee Order I. Eubacteriales.
Cells in free condition gobular; in di-
vision somewhat elliptical.......... I. Coccacegz, p. 21.
Nonflagellate

Division in only one direction,

cells single, in pairs, or chains 1. Streptococcus.
Division in two directions; cells

may remain in plates........ 2. Micrococcus, p. 21.
Division in three directions cells

may remain in_bale-like

packets. .............00005: 3. Sarcina.
Flagellate
Division in two directions...... 4. Planococcus.
Division in three directions. . 5. Planosarcina.
Cells long or short, cylindrical,

straight, division in one direc-

TOD avi este Seed Sidayveced 229 II. Bacteriacee, p. 21.
Nonflagellate. ................ 6. Bacterium, p. 21.
Flagellate

Flagella diffuse... ......... - Bacillus, p. 37.

7
Flagella polar............... 8. Pseudomonas, p. 22.

THE FUNGI WHICH CAUSE PLANT DISEASE 19

Cells spirally curved or represent-
ing part of a spiral, division in

one direction. ................ III. Spirillacee.
Cells cylindric in sheathed threads... IV. Chlamydobacteriacee.
Cells with sulphur............... Order II. Thiobacteriales.

Motile rods in pseudoplasmodial masses
in a gelatinous matrix, and forming
highly developed cysts....... Order III. Myxobacteriales.

The species of families 3 and 4 and of orders II and III, some
twenty-five genera in all, are so far as is known, unimportant as
regards plant disease. All of the known plant pathogens belong
to one or other of the first two families of the Eubacteriales. Each
of these families contains several dangerous parasites upon ani-
mals, e. g., Bacillus typhosus, Spirillum cholera-asiatice, Bacte-
rium tuberculosis.

The specific characters of bacteria are chiefly chemical or
physiological and rest in the relation of the forms to oxygen, gel-
atine liquefaction, fermentation of various sugars, acid production,
relation to nitrogenous compounds, chromogenesis, ete ta

To enable brief expression of these characters the Society of
American Bacteriologists endorses the following numerical sys-
tem.*

A NuMericaL SysTEM oF RECORDING THE SALIENT CHARACTERS OF AN
Orcanism. (Group NUMBER)

100. Endospores produced
200. Endospores not produced
10. Aérobic (Strict)
20. Facultative anaérobic
30. Anaérobic (Strict)
1. Gelatine liquefied
\ 2. Gelatine not liquefied
0.1 Acid and gas from dextrose
0.2 Acid without gas from dextrose
0.3 No acid from dextrose
0.4 No growth with dextrose

* This will be found useful as a quick method of showing close relationships
inside the genus, but is not a sufficient characterization of any organism.

20 THE FUNGI WHICH CAUSE PLANT DISEASE

01 Acid and gas from lactose

02 Acid without gas from lactose
03 No acid from lactose

.04 No growth with lactose

.001 Acid and gas from saccharose
.002 Acid without gas from saccharose
.003 No acid from saccharose

004 No growth with saccharose

.0001 Nitrates reduced with evolution of gas
0002 Nitrates not reduced

.0003 Nitrates reduced without gas formation
.00001 Fluorescent

00002 Violet chromogens

.00003 Blue u

.00004 Green -

.00005 Yellow ”

.00006 Orange ”

.00007 Red a
.00008 Brown
.00009 Pink ”

00000 Non-chromogenic

.000001 Diastasic action on potato starch, strong
000002 Diastasic action on potato starch, feeble
.000003 Diastasic action on potato starch, absent
.0000001 Acid and gas from glycerine

.0000002 Acid without gas from glycerine
.0000003 No acid from glycerine

.0000004 No growth with glycerine

The genus according to the system of Migula is given its proper ab-
breviation which precedes the number thus: *

BaciLius cout (Esch.) Mig. becomes B. 222.111102
BACILLUS ALCALIGENES Petr. «iB. 212.333102
PsEUDOMONAS CAMPESTRIS (Pam.) E. F. Sm. > Ps: 211.333151
BacTERIUM suicipa Mig. “Bact. 222.232203

* Incomplete group numbers are given with many of the species in suc-
ceeding pages. In these the known factors are given and the unknown or
imperfectly known are represented by dashes. These numbers were worked
out for the author by Mr. W. C. Norton, from the available literature.

THE FUNGI WHICH CAUSE PLANT DISEASE 21

The plant pathogens as yet known, with few exceptions, belong
to the two genera Pseudomonas and Bacillus between which they
are about equally divided.

In the earlier days of bacteriology and to some extent in recent
days, bacteria have been seen in diseased plant tissues and have
been placed by their observers in one genus or another and cited
as the causes of the diseases in question but without actual evi-
dence that they cause the diseases and very often without any real
evidence as to the genus to which the bacteria belonged. It is
of course usually impossible to identify such forms and they must
be dropped from consideration.

Coccacee (p. 18)

No representative of this family parasitic upon plants has yet
been reliably recorded in America. Micrococcus tritici Pril 74
upon wheat in England is probably in reality Bacillus prodigiosus
and not pathogenic. Micrococcus phytophthorus Frank **. * re-
ported as a cause of potato rot and also associated with potato
black-leg is perhaps in reality identical with Bacillus phytoph-
thorus Appel. Micrococcus nuclei Roze, M. imperiatoris -Roze,
M. flavidus Roze, M. albidus Roze, M. delacourianus Roze and
M. pellucidus Roze are assigned by Roze ” as the causes of va-
rious potato troubles in Europe, and M. populi Del.” is said to be
the cause of canker on Populus.

Bacteriacee (p. 18)

Bacterium Ehrenberg (p. 18)

These non-motile forms, perhaps owing to their lack of power
of locomotion, are comparatively rare as plant pathogens.

Bact. briosianum Pav. is given as the cause of rotting of to-
mato fruit and distortion of vegetative parts in Italy. It is
described also on Vanilla.?”

Bact. montemartinii Pav. is described as the cause of a canker
of Wisteria.!?

Bact. mori B. & L. is said to cause leaf and branch spots on
mulberry.

22 THE FUNGI WHICH CAUSE PLANT DISEASE

Bact. teutlium Metcalf.” (Group number 222.—220—.)

A short rod with rounded ends, 1.5 x 0.8 yu, before division
3 x 1 yu; non-motile, no flagella seen; no spores; Gram-positive;
agar colonies round, thin, not viscid, porcelaneous to transparent,
seldom over 0.5 ». No liquefaction. Broth clouded, precipitate
thin or none, no pellicle. Milk not coagulated. T. D. P. 45°,
10 min. Opt. 17°. Aérobic, no gas.

Beets diseased by this organism were honeycombed with pockets
filled with a viscous fluid, a practically pure bacterial culture.
The vascular tissue was not rotted. Inoculation by pricking the
bacterial exudate into healthy beets resulted in typical disease.
Pure cultures isolated by use of cane-sugar-agar gave similar results.
Three weeks after inoculation the exudate-forming pockets were
typically developed. Surface inoculation failed and there is no
evidence that the organism can infect except through wounds.
No rotting followed inoculation on potato, white turnip, radish,
tomato, or apple.

Bact. pini Vuill.*° was found in tissue of pine galls and regarded
as their cause.

Bact. fici Cav. is reported as the cause of a disease of figs.

Bact. scabigenum Busse & v. Faber is described as the cause
of scab of sugar-beets in Germany:*!

Pseudomonas Migula (p. 18)

Short or long rods motile by polar flagella, fig. 10, whose num-
ber varies from one to ten but is most commonly one. Endo-
spores are sometimes present. The cells in some species adhere
to form short chains. The basis of separation into species is the
growth upon gelatine, character of the colonies, chromogenesis
and numerous other cultural characters.32* 33 34

Something over seventy-nine species are known, at least fifteen
of which cause diseases in plants, some of them very serious.
Many other species occur in water, soi] and manure, while others
are suspected animal pathogens.

One prominent group of plant pathogens,*4 the yellow Pseudo-
monas group, contains, according to Smith, Ps. campestris, Ps.
phaseoli, Ps. hyacinthi, Ps. stewarti, Ps. juglandis, Ps. vascularum,
Ps. dianthi, Ps. amaranti, Ps. malvacearum. These, he says,

THE FUNGI WHICH CAUSE PLANT DISEASE 23

agree in the following particulars: They are yellow rod-shaped
organisms of medium size, straight or slightly crooked with
rounded ends. The segments multiply by fission, after elongation.
They are generally less than 1 » in diameter. The segments
occur singly, in pairs or in fours joined end to end, or in clumpy
masses of variable size (zodgloez), more rarely they are united
into long chains or into filaments in which no septa are visible.
Endospores have not been observed. The segments are motile by
means of one polar flagellum which is generally several times as
long as the rod, and may be wavy or straight when stained. The
species grow readily on all of the ordinary culture media, but so
far as is definitely known all are strictly aérobic. None are gas
producers: They do not reduce nitrates to nitrites. The yellow
color appears to be a lipochrome and in the different species varies
from deep orange and buff-yellow, through pure chrome and
canary-yellow, to primrose-yellow and paler tints.

Ps. geruginosus Del. possibly identical with Ps. flourescens-
putridus Fliigge is the cause of a leaf and stem disease of tobacco
in France.”

Ps. avenz Manns, (Group number 111.2223032.) A short rod
with round ends, 0.6tolwxito2y. Actively motile, generally
by one polar flagellum, occasionally by two or three. Gram
negative. What seem to be endo-
spores are found in old cultures. On
agar stroke, growth very slow, fili-
form, rather flat, glistening; margin
smooth, opaque to opalescent; non-
chromogenic. Liquefaction occurs on
gelatine in seven to twelve days.
Broth is slowly clouded. Agar colo-
nies, amorphous, round with surface
smooth, edges entire. No gas in
dextrose, saccharose, lactose, maltose, Fis. 1 Ee even After
or glycerine. Ammonia and_ indol .
not formed. Nitrates reduced to nitrites. T. D. P. 10 min.,
60°, Opt. 20° to 30°.

This organism was isolated and described by Manns in 1909,*
as the cause of a serious oat blight. Inoculations with it alone by

24 THE FUNGI WHICH CAUSE PLANT DISEASE

hypodermic injection produced only limited lesions but similar
inoculations with a mixed culture of Ps. avenze and Bacillus avene
produced typical disease. Manns, moreover, noticed that the
virulence of the Pseudomonas decreased when kept in culture free
from the Bacillus, also that in the disease as it occurs in nature
these two organisms are associated. His conclusion is that the
Pseudomonas is the active parasite and that the Bacillus is an
important, perhaps a necessary symbiont.

Fic. 11.—Showing effect of inoculation of Ps. campestris into cabbage plants. Nos.
fecona six weeks after inoculation. No. 3, check plant uninoculated. After
ussell.

Infection in nature is chiefly stomatal by spattering rain.
Soaking of seed in suspensions of bacteria did not produce the
disease. Inoculations on wheat failed, though from one variety
of blighted wheat, Extra Square Head, the typical organism was
isolated. Inoculations on corn made during wet weather produced
lesions which spread rapidly and the organism was re-isolated.
Barley is said by Manns to be susceptible and what he believes to
be the same disease occurs on blue grass and timothy.

Ps. campestris (Pam.) E. F.Sm. (Group number 211.333151.)
A rod-shaped, motile, organism generally 0.7 to 3.0 x 0.4 to 0.5 y;
color dull waxy-yellow to canary-yellow, occasionally brighter or
more pale. One polar flagellum; no spores known. Aérobic but

THE FUNGI WHICH CAUSE PLANT DISEASE 25

not a gas or acid producer, gelatine liquefied. Cavities are formed
around the bundles but the organism seems to be only feebly
destructive to cellulose. A brown pigment is produced in the
host plants and on steamed cruciferous substrata. Growth
rapid on steamed potato cylinders at room temperatures, without
odor or brown pigment. Growth feeble at 7°, rapid at 17 to 19°,
luxuriant at 21 to 26°, very feeble at 37 to 38° and ceases at 40°.
T. D. P., 10 min., 51°.

mm

Fic. 12.—Ps. campestris. Section of a cabbage leaf par-
allel to the surface and near the margin, showing the
result of infection through the water-pores. After
Smith.

It is closely related to Ps. hyacinthi from which it differs chiefly
in its pathogenic properties, its duller yellow color and its higher
thermal death point. It is troublesome upon cabbage, turnips,
cauliflowers, collards; and a very large number of cruciferous
hosts, both cultivated and wild are susceptible. It enters the host
plant through the vascular system which becomes decidedly
brown.

This organism was first isolated by Pammel * (see also “*) from
rutabagas and yellow turnips in 1892; green-house inoculations
with pure cultures were made in scalpel wounds, which were then

26 THE FUNGI WHICH CAUSE PLANT DISEASE

sealed with wax. The plants showed rot in a few days and the
actual causal relation of the organism was thus established. Con-
firmatory evidence was gained by Russell *” from puncture inocula-

Fic. 13.—Ps. campestris; cross-section of a turnip
root. After Smith.

tions in cabbage and
cauliflower petioles. It
was further shown by
E. F. Smith ® that the
cabbage and turnip or-
ganisms are identical
and that the bacteria,
by solution of the cellu-
lose, produce pits and
holes through the walls
of the host cells re-
sulting eventually in
large cavities.
Infection was shown
by Russell?” and by
Smith ** % to be chiefly
through the water pores
or through wounds
made by insects; the
bacteria being air or
insect borne and de-
rived largely from in-
fected soil. After en-
tering the plant the
bacteria multiply rap-
idly, and migrate in
every direction by
means of the veins.

Studies of Harding, Stewart and Prucha *° (see also) 4? showed
that it can survive the winter on the seed and thus infect seedlings.

Ps. destructans Potter “is described as an uniflagellate organism
causing a destructive soft rot of turnips and beets in England.
Doubt has been thrown upon its identity by the work of Harding
and Morse ** and of Jones ‘4 who found supposedly: authentic
cultures to bear peretrichiate rather than polar flagella. See p. 42.

THE FUNGI WHICH CAUSE PLANT DISEASE 27

Ps. dianthi Arth. & Boll.** Though originally reported as the
probable cause of carnation leaf spot, this organism is now regarded
as a saprophyte.

Ps. fluorescens (Fligge) Mig. Straight and curved rods of
medium size in chains of two or several members. Cells 0.68 x
1.17-1.86 u. Spores not seen. Flagella 3-6 polar.

Gelatine liquefied; surrounding medium colored greenish-yellow;
Gram negative. Milk not coagulated. Indol weak. Bouillon,
turbid, fluorescent.

This organism or two varieties of it are by Barlow “ held re-
sponsible for a decay of celery. The organism was found in large
numbers in the decayed tissue; was isolated and typical rot was
induced by inoculation of pure cultures upon sterilized celery
stems.

It is also credited with two distinct types of tobacco disease in
France, one of them on seed, the other on the growing plant.
Recently Griffon ” has claimed that both of the varieties, Ps.
fluorescens liquefaciens and Ps. putrida are capable of producing
wet rot of various vegetables, carrots, rutabagas, tobacco, toma-
toes, melons, and that the latter organism is identical with Ps.
eruginosus. It is also held that B. brassicevorus and B. cauli-
vorus are forms of Ps. fluorescens.

Ps. fluorescens exitiosus v. Hall is said by van Hall * to cause
rot of Iris.

Ps. hyacinthi (Wak.) E. F.Sm., is a serious pest of hyacinths in
the Netherlands but has not yet been recorded in America.”
It is medium sized rod with rounded ends,
measuring in the host 0.8-1.2 x 0.4-0.6 u; )
actively motile by one long polar flagellum; SX
non sporiferous; liquefies gelatine slowly;
aérobic; no gas. It produces indol. Does not Fro. 14.—Ps. hyacinthi.
grow at 37°. Opt. 28 to 30°, T. D. P. 10 9 After Smith.
min., 47.5°. It is a wound parasite which grows in the vessels
forming a bright yellow slime and is closely related to Ps. cam-
pestris and Ps. phaseoli.

Ps. iridis v. Hall © is described by van Hall as the cause of
decay of shoots and rhizomes of Iris.

Ps, juglandis Pierce. (Group number -11.——5l-.) ** A rod

28 THE FUNGI WHICH CAUSE PLANT DISEASE

1-2 x 0.5 uw, with rounded ends, actively motile by one long polar
flagellum. Bright chrome-yellow in growth; disastatic ferment
present. No gas; aérobic. It was isolated from diseased nuts,
leaves, and twigs of English walnut in California in 1901. In-
oculations by spraying demonstrated its pathogenicity. The
organism is closely related to Ps. campestris but is distinguished
from it by the abundant bright yellow pigment produced upon the
surface of extracts of leaves of walnut, magnolia, fig, castor bean
and loquat.

Ps. leguminiperdus (v. Oven.) Stev.,®? said to be distinct
from Ps. phaseoli, occurs on peas and other legumes. It was
isolated, cultivated and inoculations made.

Ps. levistici Osterw.*? occurs on Levisticum.

Ps. maculicolum (McC.) Stev. (Group number 211.3332023.)
A short rod, forming long chains in some media. Ends rounded.
Size from leaf 1.5 to 2.4 » by 0.8 to 0.9 uw; in 24-hour beef-agar
culture, 1.5 to 3 uw by 0.9 uw. No spores, actively motile, one to
five polar flagella two to three times the length of the rod. Mo-
-tile in most artificial media. Involution forms in alkaline beef
bouillon. Pseudo-zoégloee in Uschinsky’s solution. Gram nega-
tive. Stains readily with carbol fuchsin and with an alcoholic
solution of gentian violet.

Agar plate colonies visible on the second day as tiny white
specks, in three to four days, 1 to 3 mm. in diameter, white,
round, smooth, flat, shining, and translucent, edges entire, with
age dull to dirty white, slightly irregular, edges undulate, slightly
crinkled, and with indistinct radiating marginal lines. Buried
colonies small, lens-shaped.

Agar streak cultures white, margins slightly undulate. Beef
bouillon clouds in twenty-four hours. Growth best at surface
where a white layer, not a true pellicle, is formed. No zodglee.
No rim.

Gelatine stab cultures liquefied in eight to ten days. Growth
from surface crateriform; slight, white, granular precipitate. Slight
green fluorescence. No separation into curd and whey. Indol
production feeble. T. D. P. 46°. Opt. 24-25°. Max. 29°. Min.
below 0°.

Isolated from cauliflower leaves on which it forms brownish to

THE FUNGI WHICH CAUSE PLANT DISEASE 29

purplish-gray spots 1-3 mm. in diameter. Pathogenicity on
this host also on cabbage was proved by inoculation. Its entrance
is stomatal.

Ps. malvacearum, E. F. Sm.** ** °° This yellow organism,
pathogenic on cotton, much resembles Ps. campestris but its slime
is more translucent on potato and it
does not attack the cabbage. It was
grown in pure culture by Smith and
successful inoculations were made by
spraying a suspension of a young agar
culture of the organism upon cotton
leaves and bolls. No description has
been published.

Ps. medicaginis Sackett.54 (Group
number 212.3332133.) A short rod,
1.2-2.4 x 0.5-0.8 yu; filaments 20.2-
37.2 p» long. No spores; actively
motile with 1-4 bipolar flagella; cap-
sules and zodgloea none. Agar streak
filiform, later echinulate, glistening,
smooth, translucent, grayish-white;
no gelatine liquefaction; bouillon
slightly turbid, pellicle on third day,
sediment scant. Milk unchanged.

Agar colonies round, grayish-white. F Tay Gabe er onal acess
No gas or indol. Optimum reaction en de ene Laver or
+15 to +18 Fuller’s scale. T. D. P.

49-50°, 10 min. Opt. 28-30°. Aérobic. No diastase, invertase,
zymase, rennit or pepsin.

It occurs as a pathogen on alfalfa and issues in clouds visible to
the naked eye from small pieces of tissue of the diseased stem or
leaf when mounted in water on the slide. These clouds under the
high power resolve into actively motile rods, relatively short and
thick. The bacteria are also found in practically pure culture in
the exudate which oozes from the diseased tissue as a clear viscous
liquid and collects in drops or spreads over the stem. Sackett
with pure culture inoculations produced the typical disease and
re-isolated the organism with unchanged characters. Re-inoculated

30 THE FUNGI WHICH CAUSE PLANT DISEASE

it again caused disease. More than a hundred inoculations by
scarification or puncture gave one hundred per cent infection.
Controls remained undiseased. Infection, stomatal or water pore,
was also secured through the apparently unbroken epidermis.
The virulence of the or-
ganism was retained after
five months on agar. It
is believed that the usual
mode of infection is
through rifts in the epider-
mis due to frost and that
the germ is wind-borne
from infected soil.

Ps. michiganense (E.
F. Sm.) Stev. (Group
number -—22.—252-.)
Rod short with rounded
ends, 0.35-0.4 x 0.8-1.0 u.
Fic. 16.—Ps. medicaginis; 48-hour agar-culture, No motility seen from
showing formation of filaments. AfterSackett. steams, Flagella apparently
polar but not seen distinctly. Agar colonies pale-yellow, smooth,
round. Agar stab canary-yellow, opaque, viscid. Bouillon moder-
ately clouded, a moderate slimy precipitate; no rim or pellicle.
Gelatine not liquefied.

The organism was described by Smith * as the cause of a stem
disease of tomatoes in Michigan. No fungi were seen but bacteria
were present in great’ numbers in the bundles also in cavities in
the pith and bark. The organism was isolated and the disease was
produced both by pure culture inoculations and by crude inocula-
tions, using an impure inoculum. The disease caused is less rapid
in development than that caused by B. solanacearum and less
browning of the infected tissue occurs.

Ps. mori (B. & L.) Stev. (Group number 222.—202-.) Rod
with rounded ends, 1.8-4.5 x 0.9-1.3 », mostly 3.6 x 1.-2 u;
motile by one, sometimes two polar flagella. No spores. Pseudo-
zodgloee present. Agar colonies round, smooth, flat. Agar
streaks spreading, flat, dull-white. Gelatine stab filiform, no
liquefaction. Milk not coagulated. No gas. T. D. P. 51.5°.

THE FUNGI WHICH CAUSE PLANT DISEASE 31

In 1894 Boyer and Lambert °° produced successful inoculations
on mulberries with an organism to which they gave the above
name, but without description.

In 1908 E. F. Smith,” plated out, from blighted mulberry
leaves collected
in Georgia, a
white species
with which he
made numerous
infections on
both stems and
leaves of mul-
berry. From
these cultures
Smith supplied
the description
quoted in part
above. The re-
lation which
Bacillus cuboni-
anus ** has to
this mulberry
disease is un-
known.

Ps. phaseoli E. F. Sm. A short round-ended rod, wax-yellow
to chrome; motile; anaérobic. Milk coagulates, and the whey
slowly separates without acidity; gelatine liquefies slowly. Growth

feeble at 37°, none at 40°. T. D. P. 10 min.,

Fic. 17.—Ps. medicaginis; agar colonies 7 days old, deep
aud surface colonies by reflected light. After Sackett.

49.5°. A starch enzyme is produced and the
middle lamella also dissolved.
This organism is pathogenic to beans and
/ some related legumes and is closely related to
Ps. hyacinthi and Ps. campestris. The bean

Fic. beet al eat disease, occasioned by it was noted and as-

; cribed to bacteria by Beach * and by Hal-
sted © in 1892, and the organism was described by E. F. Smith
in 1897 © after it had been grown in pure culture and successful
inoculations had been made.

32 THE FUNGI WHICH CAUSE PLANT DISEASE

Ps. pruni, E. F. Sm. The organism resembles Ps. campestris
but is distinguished from it by its feebler growth on potato and
by its behavior in Uschnisky’s solution which it converts into a
viscid fluid. It consists of small rods, motile by one to several
polar flagella. T. D. P. 51°. Gelatine not liquefied. Casein
slowly precipitated and later redissolved. No gas.

The bacteria enter through the stomata of the Japanese plum;
cause small watery spots on green fruit and leaves, and finally the

Fic. 19.—Earlicst stage of fruit spot on green plums, due to Ps.
pruni. The bacteria entered through the stoma. After Smith.

death of the affected tissue. In earliest disease they are limited
to the substomatal space but gradually they invade more distant
tissue. Wounds are not necessary to infection. It seems to have
been seen first on the peach in 1903 by O’Gara in Georgia and in
the same year by Clinton in Connecticut. Rorer ® by numerous
cultures and cross inoculations proved this same organism re-
sponsible for a leaf, twig and fruit disease of peaches. In the twig
the bacteria were present in great numbers in the bast.

Ps. radicicola (Bey.) Moore.*4 The legume root-tubercle or-

THE FUNGI WHICH CAUSE PLANT DISEASE 33

ganism, by some regarded as a parasite, though beneficial, and by
others regarded as a mutualistic symbiont will not be discussed
here owing to its beneficial character.

LT y

me

pea Pas
Byres

Fic. 20.—Part of sweet-corn stem parasitized by Ps. stewarti. After Smith.

Ps. savastanoi (E. F. Sm.) Stev. A rod with rounded ends,
solitary or in short chains, 1.2-3 x 0.4-0.8 u; motile; aérobic; non-
sporing; flagella 1-several, often 2-4, polar. Standard agar,
surface colonies, white, small, circular, smooth 1.5-3 mm. at three
days, edge entire; bouillon thinly clouded, precipitate slight, white,
no rim or pellicle. On gelatine no liquefaction; colonies white,

round, erose, margin pale.

34 THE FUNGI WHICH CAUSE PLANT DISEASE

From swellings known as olive tubercles on Californian olive
branches, E. F. Smith isolated this organism © which is in part
Ps. olese-tuberculosis and which may bear relation to several other
olive bacteria previously described in Europe.

The organism when inoculated by puncture into young olive
shoots produced the characteristic tubercle. Later it was re-
isolated from these artificially produced tubercles and used in a
second series of inoculations which gave a second crop of tubercles.
Controls showed no infection and healed promptly. The oleander
was not susceptible to infection.

Smith’s results are not in full accord with much of the European
work on the olive tubercle.

Ps. sesami Malk. causes disease on sesame ®.

Ps. stewarti, E. F.Sm. A medium size rod, 0.5-0.9 ux1-2 un,
with rounded ends, and 1 polar flagellum. Buff-yellow to chrome
or ochre color; non-liquefying; does not separate casein in milk.
T. D. P. 10 min., 53°.
Agar colonies subcir-
cular, becoming lobate;
bouillon rendered tur-
bid with yellow-white
precipitate. No gas.

The bacterial corn
blight of this organism
was first described by
Stewart in 1897” and
attributed to bacteria.
The organism was de-
scribed by E. F. Smith
in 1890® from a cul-
ture furnished by Stew-

Fic. 21.—Various forms of Ps. stewarti, grown on art. Definite proof by
potato 3 agar; a and b are typical forms. After inoculation of the

is causal relation of this
particular organism to the disease was adduced in 1902 by
sprinkling bacteria upon the leaves. 7 Some plants showed
typical constitutional symptoms during the first month, most of
them in two or three months when the plants were several feet

THE FUNGI WHICH CAUSE PLANT DISEASE 35

high. In these plants the vessels become plugged with pure cul-
tures of Ps. stewarti from tip to base. Small holes filled with
yellow slime appeared later in the parenchyma. Wounds were en-
tirely unnecessary to infection, though the vessels are the primary
seat of disease.

Ps. syringe v. Hall” causes disease of Syringa and other plants.

Ps. tumefaciens (S. & T.) Stev.”* (Group number
212.2322023.) Vegetative cells taken directly from a gall usually
06to10uxl2tologp

When grown on agar for two days 2.5 to 3 » x 0.7 to 0.8 » or
occasionally wider. Endospores not observed. Motile by means
of one, sometimes two or three terminal flagella; viscid on agar
but capsules not demonstrated. Readily stained in ordinary basic
anilin stains; Gram negative. Agar surface colonies usually come
up in from four to six days at 25°,

ceo
white, smooth, circular; margin even, al I°7 |
shining, semi-transparent, maximum a
size 2 to 4 mm. Agar streak; growth x 5
moderate, filiform. On sterile potato >.
cylinders growth more rapid, in one \4 oS \
or two days covering the entire surface
of the cylinder; smooth wet-glisten-
ing, slimy to viscid, odorless; potato
cylinder grayish, darker with age, a A -4
never yellow. Gelatine colonies dense,
white, circular, small, non-liquefying, *";22—Fiaeels ee, tom ttar
medium not stained. In beef broth Smith.
clouding often absent or inconspicuous, rim of gelatinous threads
present, also more or less of pellicle; in young cultures very deli-
cate suspended short filaments, best seen on shaking. Milk coagu-
lation delayed; extrusion of whey begins only after several days;
litmus milk gradually blued, then reduced. Cohn’s solution,
growth scanty or absent, medium non-fluorescent.

No gas produced; organism aérobic in its tendencies; nitrates
not reduced. Indol produced in small quantity, slowly. Slight
toleration for citric, malic, and acetic acids. Toleration for alkali
slight. Optimum reaction between +12 and +24, Fuller’s
seale. T.D. P.51°. Opt. between 25° and 28° Max. +37°. Growth

36 THE FUNGI WHICH CAUSE PLANT DISEASE

occurs at 0°. Milk, bouillon, dextrose peptone water with calcium
carbonate are the best media for long continued growth.

The following are recommended as quick tests for differential.
purposes. Time of appearance of colonies on +15 agar plates
made from the tumors; young agar stroke cultures; behavior in
milk and litmus milk; growth on potato; behavior in Cohn’s
solution; stringy ring and suspended filaments in peptonized beef
bouillon; inoculations into young, rapidly growing daisy shoots
or into growing sugar-beet roots. ¢

The organism is readily plated from young sound galls, i. e.,
those not fissured or decayed.

In galls on the Paris daisy (Chrysanthemum frutescens) these
bacteria were found in small numbers. By plating they were
obtained in pure culture and puncture inoculations repeatedly
resulted in the characteristic gall. From these the organism was
reisolated and the disease again produced, thus giving conclusive
evidence that the organism is the actual cause of the gall. Swell-
ings began four or five days after inoculation and in a month they
were well developed though they continued to enlarge for several
months, reaching a size of 2-5 cm. in diameter.

Tumor-producing Schizomycetes have also been isolated from
over-growths on plants belonging to many widely separated
families (Composite to Salicacez). Natural galls have been
studied on Chrysanthemum, peach, apple, rose, quince, honey-
suckle, Arbutus, cotton, poplar, chestnut, alfalfa, grape, hop, beet,
salsify, turnip, parsnip, lettuce, and willow. The organisms from
these sources are closely alike on various culture media, and many.
of them are readily cross-inoculable, e. g., daisy to peach, radish,
grape, sugar-beet, hop; peach to daisy, apple, Pelargonium,
sugar-beet, poplar; hop to daisy, tomato, sugar-beet; grape to
almond, sugar-beet; poplar to cactus, oleander, sugar-beet; willow
to daisy. With eight of these organisms tumors have been pro-
duced on sound specimens of the species from which obtained.
Some cross-inoculate more readily than others, and there are also
slight cultural differences. Thus, it is probable that there are
several races of the gall-forming organisms varying more or less
in amount of virulence and in adaptability to various hosts. In
general it is said that all plants susceptible to crown galls, i. e.,

THE FUNGI WHICH CAUSE PLANT DISEASE 37

those on which the galls have been found in nature, are susceptible
to artificial cross inoculation. Hard gall, hairy root, and soft gall
are also all due to infectious bacteria.

As tentative hypotheses Smith assumes either: (1) That the
hairy root organism while resembling the crown gall organism is
not identical with.it; or (2) That they are the same, and that if
infection takes place in a certain group of cells an ordinary gall
will develop, while if other special groups of cells are first invaded,
i. e., the root anlage, then a cluster of the fleshy roots will develop.
Some of his inoculation experiments point to the latter conclusion.

Ps. vascularum (Cobb) E. F. Sm. 7” ™ * is parasitic on sugar
cane, filling the bundles with a yellow slime. It has not been re-
ported in America.

Ps. sp. indet. A short hie 2-4 x 1-1.5 yu, actively motile by

1-3 polar flagella, was isolated from diseased spots on the larger
veins and petioles of beet leaves by Brown.” The organism was
successfully inoculated in pure culture, disease produced, and the
organism reisolated. It is infective as well for lettuce, sweet
pepper, nasturtium, egg plant and bean. Agar colonies are creamy
white, thin, circular, turning the surrounding agar yellow-green
in three days. Gelatine is liquefied; litmus milk turns blue;
bouillon is clouded. Opt. 28°.

Ps. sp. indet. A short rod, 2-4 » long, motile by 1-3 polar
flagella was isolated from diseased nasturtiums (Tropeolum)
leaves by Jamiesson.” Pure culture inoculations induced typical
disease. The organism clouds bouillon; produces on agar small,
round, bluish-white colonies; liquefies gelatine and does not pro-
duce gas. Opt. 25°. T. D. P. 49-50°, 10 min. It is pathogenic
also for sweet-pea, lettuce, pepper, sugar-beet and bean.

Bacillus Cohn. (p. 18.)

This genus differs from Pseudomonas only in its peritrichiate,
not polar, flagella. Endospores are often present. Of the four
hundred and fifty or more species nineteen at least are known to
be plant pathogens. Numerous animal pathogens also belong to
this genus, notably B. typhosus, B. pestis.

B. ampelopsore Trev. is said to cause grape galls in Europe,”
but the evidence is by no means conclusive. Cf. B. uve.

38

THE FUNGI WHICH CAUSE PLANT DISEASE

B. amylovorus (Burr.) De Toni. (Group number 221.——0—.)
Bacillus in broth, 0.9-1.5 x 0.7-1.0 », longer when older.
Gram positive; no capsule; flagella several; no spores; broth

clouded, pellicle slight.

\

Gelatine shows slow, crateriform lique-
faction. Agar, buried colonies white, surface
colonies elevated, circular wet-shining, margin
irregular. Milk coagulated in three-fourths of
a day, later digested to a pasty condition.
Opt. 25-30°. T. D. P. 43.7°, 10 min. Faculta-

’ tive anaérobe. Indol produced; no gas; no pig-

ee:

Fic. 23.—B. amylo-
vorus, multiply-
ing by fission.
After Whetzel
and Stewart.

ment.

Bacteria were noted in blighted pear twigs by
Burrill in 1877.8" 85 In 1880 he ** demonstrated
the communicability of the disease by intro-
ducing the bacterial exudate into healthy pear
trees as well as into apple and quince trees.

This constitutes the first case of plant disease

definitely at-

tributed to bacteria. Burrill’s results were confirmed by Arthur

in 1884 ® by one hundred and twenty-one puncture
inoculations, using the exudate, also a bacterial
suspension from diseased twigs. He further demon-
strated the susceptibility of Juneberry and haw-
thorn. Usually the disease appeared about a
week after inoculation. Attempted raspberry and
grape inoculations failed.

Arthur placed the whole matter on a firm foun-
dation by passing the bacteria through a long
series of artificial cultures and then by inocula-
tions, showing that they were capable of causing
the blight.* 8” He further demonstrated that the
bacterial exudate from the tree, when freed of
bacteria by filtration, could not produce disease.
The results of an extensive study of the bacteria on
various media; of their morphology and stain

Fic. 24.—Claw
from bee’s foot
with blight
bacteria on
and about it
showing the
relative _ size.
After Whet-
zel and Stew-
art.

reactions were published by Arthur in 1886.% Bacteria were
shown to penetrate twigs 3-4 dm. beyond their area of visible

effect?”

In 1902 Jones ® isolated an organism from blighted plum trees.

THE FUNGI WHICH CAUSE PLANT DISEASE 39

This he demonstrated by culture and cross inoculation in fruits to
be identical with the pear blight organism, though inoculations in
plum twigs did not give disease, presumably due to the high re-
sistance of this plant. Similarly Paddock has shown this organism
to attack the apricot. Detmers has reported what she regarded
as this blight caused by this Bacillus on blackberries.®!

Other hosts are hawthorn, shad bush, mountain ash.

By inoculations with pure cultures of the apple body-blight
bacteria, blight upon twigs and blossoms was produced by Whetzel
in 1906,** thus proving the identity of these two forms of disease,
an identity asserted first by Burrill.%

Fic. 25.—B. aroidex. After Townsend.

B. apii (Brizi.) Mig.*4 is reported as the cause of a celery rot,
which is possibly identical with a bacterial rot reported earlier
by Halsted.

B. araliavorous Uyeda, described on Ginseng in Korea is per-
haps also the cause of soft rot of Ginseng in America.*® The
organism was isolated and studied by Uyeda who made inocula-
tions.

Pseudomonas araliz and Bacillus koraiensis were also com-
monly present in the Oriental disease.”

B. aroidee Town. (Group Number 221.2223022.) 38

This organism was described in 1904 as the cause of soft rot of
calla % corms and leaves. The bacteria were present in almost
pure culture in affected tissue and by puncture inoculation in pure
culture produced the typical disease in a few days.

Townsend regarded the organism as distinct from B. carotov-
orus, B. oleracee, B. hyacinthi septicus and Pseudomonas de-

40 THE FUNGI WHICH CAUSE PLANT DISEASE

structans. Harding and Morse, however, believe it specifically
identical with B. carotovorus. See p. 42.

B. atrosepticus v. Hall,” was isolated from ducts of potatoes
affected with black leg.

B. avenz, Manns.** This is the symbiont of Pseudomonas
avene. See p. 23.

(Group number 222.2223532.) A very actively motile bacillus,
short, rod-shaped with rounded ends, 0.75 to 1 x 1.5 to 2 uz.

Fic. 26.—Plate culture of B. avenac, on nutrient glucose agar,
four days at 30°C. After Manns.

Gram negative; endospores not observed; flagella many, diffuse,
long, undulate; growth on agar stroke rapid, filiform, white,
glistening, later somewhat dull, margin smooth, growth rather
opaque, turning yellow third day; gelatine not liquefied; broth
clouded and on the second day showing heavy yellow precipitate;
milk coagulated at end of two weeks with extrusion of whey;
agar colonies round, entire, surface smooth, slightly raised. No
gas in dextrose, saccharose, lactose, maltose, or glycerins. Indol
production moderate; nitrates reduced to nitrites. T. D. P. 10
min., 60°; Opt. 20-30°

THE FUNGI WHICH CAUSE PLANT DISEASE 41

B. bete Mig. is reported as the cause of gummosis of beet.

B. brassicevorus Del. isolated from diseased cabbage 1°! is per-
haps identical with Pseudomonas fluorescens. See page 27.

B. carotovorus Jones. (Group number 221.1113022.) From
agar 1-2 days: old as by
short or long rods, in
short or long chains.
0.7-1.0 x 1.5-5 p, com-
monly 0.8 x 2 yw; ends
rounded. No spore;
flagella 2-10, peritri-
chiate; no capsule;
Gram negative. White
on all media. Agar
slope filiform to spread-
ing, glistening, opaque
to opalescent. Ingela-
tine stab; liquefaction
crateriform to infun-
dibuliform. Broth
clouded, pellicle thin
to absent, sediment
flocculent; milk coagu-
lated. Agar colonies,
round, smooth, entire
to undulate, amor- .
phous or granular. Fic. 27.—B. Geroloverus 9 yess Ebert cells of the
Some gas in dextrose, ° :
lactose and saccharose, nitrates reduced to nitrites; indol feeble.
T. D. P. 48-50°. Opt. 25-30°.

A considerable number of cultivated plants suffer soft rot from
the attacks of a non-chromogenic liquefying bacillus. Among the
plants so affected are cabbage, turnips and other crucifers; parsnip,
carrot, mangel, sugar-beet, potato, celery, tomato, Jerusalem
artichoke, asparagus, rhubarb, onion and iris.

In 1901, Jones reported an organism isolated from rotting carrots
which he named B. carotovorus. ™ It disorganized tissue
by solution of the middle lamella; and infection into wounds led

42 THE FUNGI WHICH CAUSE PLANT DISEASE

to decay of roots of carrot, parsnip, turnip, radish, salsify, of
onion bulbs, hyacinth corms, cabbage heads, celery stalks and
fruits of tomato, pepper and egg plant. Jones found no decay pro-
duced in young carrot or parsnip plants, fruits of orange, banana,
apple, pear, cauliflower head,* Irish potato tuber, beet root or
tomato stems. Infection
did not occur unless the
epidermis was broken. The
rotten mass was always
soft, wet, and exuded a

liquid clouded with bac-
teria.
NS Jones *? in 1909 made an

Fic. 28.—B. carotovorus. After Jones. exienewe study at the eyto-

litic enzyme of this germ.
This enzyme was separated by heat, filtration, formalin, phenol,
thymol, chloroform, diffusion, alcohol, and its conditions of pro-
duction and action investigated. Heating the enzyme to 60° in-
hibited its activity to a marked degree; higher than 63° inhibited
it entirely; chloroform, thymol and phenol did not retard its ac-
tion. No loss was suffered through alcoholic precipitation and
resolution. The dried enzyme remained active for fully two
years. Its effect was greatest at 42°, less at 32° and 48°. No
diastatic action was observable.

In 1909 Harding and Morse,*®* from an extended study of some
12,000 cultures of non-chromogenic, liquefying soft-rot bacilli
of some forty-three pathogenic strains (including B. carotovorus,
B. oleracez, B. omnivorus, B. aroidex and what Potter regarded
as Pseudomonas destructans), from six different vegetables, con-
clude that ‘unless later studies of the pathogenicity of these cul-
tures shall offer a basis for subdividing them, there is no apparent
reason why they should not all be considered as somewhat variant
members of a single botanical species.

This conception would lead to the abandonment of the supposed
species mentioned above and the recognition of all of them under
their oldest described form, B. carotovorus Jones, which in our

*Harding and Stewart later showed that it is capable of rotting cauli-
flower.

THE FUNGI WHICH CAUSE PLANT DISEASE 43

present knowledge seems certainly to be the most wide spread,
common and destructive of the soft rot bacteria. Some, perhaps
much, of the rot of crucifers generally thought to be due to Pseudo-
monas campestris is probably caused by B. carotovorus. See
Harding & Morse.*

B. caulivorus, Pril. & Del. has been reported as the cause of
spots on grapes under glass,” also as a parasite on a large number
of other plants among them Pelargonium, potato, begonia, clem-
atis. It is later stated that this is probably really a variety of
Ps. putrifaciens liquefaciens.

B. cepivorus Del. (possibly a Bacterium) is recorded on onion
bulbs.®!

B. coli (Esch.) Mig. or an organism indistinguishable from it is
held by Johnston ’® capable of causing rot of soft tissues of the
cocoanut plant and is perhaps responsible for cocoanut bud
rot.

.B. cubonianus Macc. was originally described as the cause of
mulberry disease (cf. Ps. mori). This organism, or at least one
that. was regarded as indistinguishable from it, has been men-
tioned as the cause of a disease of hemp.

B. cypripedii Hori is a medium sized slender, non-sporulating
form with four flagella.’

B. delphini E. F. Sm. This is a motile, gray-white, nitrate-
reducing, non-liquefying organism. On agar young colonies small,
circular, wrinkled. Grows well at 30°, not at all at 37.5°. T. D.
P. 48-49.1°.

The cause of stomatal infection of larkspur resulting in sunken
black spots on leaves and stems.’

B. elegans Hegyi is reported on lupine.””

B. dahliz Hori & Bakis is on dahlia.

B. gossypini Stedman was reported by Stedman 108 as the
cause of cotton-boll soft rot in Alabama; much doubt, however,
remains as to its actual identity and causal relation. It was de-
scribed as a short, straight, spore-forming motile bacillus; 1.5 x
.75 w; aérobic; non-liquefying (?).

B. gummis Comes. has by some been held responsible for gum-
mosis or mal nero of the grape vine ! though others discredit this
idea.

44 THE FUNGI WHICH CAUSE PLANT DISEASE

B. haria Hori & Miy. is a parasite of the Japanese basket
willow.!®”

B. hyacinthi septicus Heinz,!”° is recorded as the cause of a soft
white rot of the hyacinth.

B. iactuce Vogl. is said to cause a lettuce disease.!!

B. lycopersici Hegyi has been described as the cause of a rot
of tomatoes.!!”

B. maculicola Del. is regarded as the cause of a tobacco leaf
spot.!8

B. melanogenus P. & M.?!‘is recorded in England on potatoes.

B. melonis Giddings.!!°

An actively motile bacillus, 0.6-0.9 x 1-1.7 wu; flagella 4-6
peritrichiate; nospores. Gram negative. Broth strongly clouded,
no pellicle or ring,
slight sediment. Agar
stroke slimy, glistening
translucent; colonies
round or ameeboid. In
gelatine stab liquefac-
tion infundibuliform in
two days. Milk co-
agulated with abun-
dant gas. Nitrite pro-
duction abundant; indol
slight. T. D. P. 49-
50°. Opt. 30°. The
vegetables rotted were
muskmelon, citron, car-
rot, potato, beet, cu-
cumber and turnip.

In the soft rot caused

Fic. 29.—Photomicrograph of B. melonis. a, show-
ing nee Peco e) in agar hanging block cul-
ture; b, with flagella stained by Léwitz method. 7 j i i
Ate Gide by this organism in

muskmelons, motile
bacteria were observed in abundance by Giddings in 1907. Plating
gave pure cultures which by inoculation tests were shown to be
those of the causal organism of the rot. Decay is produced by
solution of the middle lamella by enzymic action, the remainder
of the walls withstanding the attack. The bacteria are thus

THE FUNGI WHICH CAUSE PLANT DISEASE 45

strictly intercellular. Wound inoculations in muskmelon generally
gave complete decay in from three to seven days. Similar inocula-
tion of citron and cucumbers resulted in decay, though inoculation
into squash did not. No decay of musk-
melon followed applications of the bacteria
to unbroken surfaces.

B. mycoides Fliigge. (Group number
—22.1--—-8-.)

Rods thick, 0.95 x 1.6-2.4 yu, usually in
long threads, sporiferous. Spores elliptical,
1.3-1.48 x 0.7-0.9 mm. Gelatine colonies
white with mycelium-like outgrowths; gela-
tine liquefied. Pellicle formed in broth.
Gram positive.

This common soil organism has been held
responsible for a disease of beets.!!6

B. nicotianze Uyeda is ascribed as the
cause of a tobacco wilt in Japan 1!" "8 which
closely resembles that caused by B. sola-
nacearum in America.

The bacillus is 1-1.2 x 0.5-0.7 p with
rounded ends, actively motile by peritri-
chiate flagella. Spores are produced. A
complete physiological study is to be found
in the articles above cited.

Bacillus olezw (Arc.) Trev. (Group num-
ber —22.333-0—.) C. O. Smith describes
the organism as a motile rod with rounded
ends, 1.5-2.5 x 0.5-0.6 uw. On agar slant
growth thin, gray-white, spreading; colonies
circular, whitish. On gelatine no liquefac-
tion. Milk not coagulated. Distribution of Fyc. 30 —Cultures of B.
flagella not stated. eee

In oleander tubercles on leaves and twigs, as After Gid-
and in olive tubercles C. O. Smith #° found ;
bacteria which he regards as this species. Upon puncture inocu-
lation in both olive and oleander, tubercles were produced. Con-
trols were not diseased. The organism was reisolated from the

46 THE FUNGI WHICH CAUSE PLANT DISEASE

artificially produced knot with unchanged characters. E. F.
Smith’s results ® do not agree with those of C. O. Smith. (See
Pseudomonas savanastoi.)

B. oleracee Harr. (Group number 221.1113022.) 127122

This organism was studied by Harrison in 1901 in Canada where
it was found associated with a soft rot of cauliflower, cabbages and
turnips. In the rotting tissue it was always present; it was iso-
lated, and upon inoculation and cross inoculation characteristic
infection followed. The organism was reisolated in unchanged
character. The chemical products of the bacillus, secured by
filtration, also produced the characteristic tissue changes. Sec-
tions of diseased tissue showed the bacteria in the intercellular
spaces, occupying the position of the middle lamella which was
softened and eventually dissolved by the bacterial enzymes.

Harding and Morse ** from their extensive studies conclude
that this form is identical with B. carotovorus. See p. 42.

B. omnivorus v. Hall is described by van Hall !** as the cause of
a soft rot of iris shoots and rhizomes. According to Harding &
Morse ** it does not present characters sufficient to distinguish it
from B. carotovorus. See p. 42.

A species closely related to B. omnivorus is described by Uyeda 14
as the cause of adiseaseof Zingiber. The organism was isolated and
studied and the disease produced by inoculation with pure culture.

B. oncidii (Pegl.) Stev. is mentioned }% as the cause of an
orchid leaf spot.

B. oryze Vogl. has been mentioned as the possible cause of
brusone ?75 of rice.

B. phytophthorus Appel: (Group number 221.21230—.) A
non-sporiferous rod, 0.6-0.8 x 1.5-2.5 yu, actively motile by per-
itrichiate flagella. Gram negative. It rots potatoes, cucumbers,
etc.; is aérobic or a facultative anaérobe; grayish white on agar;
surface colonies round, smooth; gelatine liquefaction moderate;
bouillon clouded; no indol; no gas. Nitrate changed to nitrite.
Milk coagulated and casein precipitated. Opt.28-30°. T.D.P.47°.

It was described by Appel !” of Berlin as the chief cause of
potato black-leg. The description given above is by E. F. Smith 1%
and was made from Appel’s organism. Smith also isolated it from
potatoes grown in Maine and in Virginia.

THE FUNGI WHICH CAUSE PLANT DISEASE 47

It is closely related to but is not identical with B. solanisaprus
and B. atrosepticus.!%

B. populi Brizi is said to cause galls on the poplar ™.

B. pseudarabinus R. G. Sm. is capable of producing on inocu-
lation a crimson-red gum in the vessels of sugar cane and is per-
haps responsible for a disease showing this symptom.

B. rosarum Scalia is the name given to a very imperfectly
described organism said, on scant evidence, to be the cause of rose
tumors or crown galls.®

B. sesami Malk.® Malkoff in infection experiments caused a
disease of sesame with this organism.

B. solanacearum E. F. Sm. (Group number 212.333-8—.)
A medium sized, easily stained, strictly aérobic bacillus with
rounded ends; about 114-3 times longer than broad; 0.5 x 1.5 yu.
Motile, sluggish or active; flagella long, diffuse. Spores not
known. Zoéglcea occur in liquid media as small, white flecks or
as surface rings. It grows well at 20-30°. Milk is saponified with
no casein precipitation or acidity. Gelatine not liquefied. Agar
surface colonies, dirty-white. Agar streaks first dirty-white, later
yellowish to brownish-white, then brown. On potato as on agar,
but darker, with substratum and fluid browned. No gas from
cane sugar, lactose, maltose or dextrose.

The disease caused by this bacillus upon tomato and other
plants was early studied by Halsted *4183 and perhaps by Bur-
rill.434185 Halsted made inoculations which produced the disease
but he did not use pure cultures. The first complete account of
the causal organism was given by E. F. Smith ' 1%” in 1896.

In its hosts the bacillus is found in the pith, in the xylem which
is browned, and more rarely in the bark. From the cut ends of in-
fected ducts bacteria exude as a viscid ooze and the diseased ducts
may be traced to great distances through the plant, even from root
to leaf. From the bundles the organism later invades other tissues.

Needle prick inoculations in tomatoes and potatoes with pure
cultures, were followed after several weeks (tomato) by typical
disease. Inoculations in Irish potato resulted similarly, though in
this host the parenchyma and bark were eventually invaded, and
the tuber was reached through its stem end and rotted. In South
Carolina, Smith noted the disease on egg plants and crude cross

48 THE FUNGI WHICH CAUSE PLANT DISEASE

inoculations were made to tomato. Smith demonstrated experi-
mentally the efficiency of the potato beetle in transmitting the
disease.

The disease was described for tobacco by Stevens }*8 and Stevens
and Sackett.1°°

Successful inoculations were reported upon tobacco by E. F.
Smith in 1909 !° though in his earlier trials tobacco and pepper
gave negative results when inoculated with this bacillus. In addi-
tion to the above hosts it is known to grow upon Datura, Solanum
nigrum, Physalis and Petunia.

B. solanicola Del. was reported as the cause of a potato stem
disease.141

B. solaniperda Mig. (Group number 121._---0Q—-.) A rod,
2.54 x 0.7-0.8 uw, with rounded ends, often in long chains; actively
motile; spores present. Agar colonies dirty-white; gelatine liquefied.
This was shown by Kramer in 1890 !*? to be the cause of soft rot
of potatoes. The organism
was grown in pure culture
and inoculated on potatoes
producing the characteris-
tic decay. The germs enter
through the lenticels, con-
sume the sugar, then at-
tack the intercellular sub-
stances and the cell wall.
Later the albuminous sub-
stances are destroyed.

B. solanisaprus Harr.
(Group number 221.212-0—
—.) M43

Fic. ee enieiles of B. solanisaprus. A bacillus with rounded

: ends, 154 x 0.60.9 u,

variable in culture; no capsule; actively motile by 5-15+ peritri-
chiate flagella; no spores seen. Gram negative. Gelatine colonies,
punctiform 0.25 mm. at two days; gelatine stab filiform. Liquefac-
tion noticeable on the thirty-fifth day. Agar colonies punctiform
at two days, 1-5 mm., gray-white, slimy, flat. Bouillon turbid
with fine sediment; ring, and thin band present; milk curdled.

THE FUNGI WHICH CAUSE PLANT DISEASE 49

Gas only in mannite and lactose. Nitrate reduced to nitrite.
Opt. 25-28°. T. D. P. 54°, 10 min.

It was found constantly associated with a type of potato disease
which Harrison regarded as distinct from black-leg and from the
disease caused by B.
solanacearum. It was
repeatedly isolated
from diseased tubers,
stems and leaf veins
and occurred in prac-
tically pure culture in
freshly infected tissue.

The organisms first
appeared in the ducts
and thence invaded
the surrounding tis-
sue, dissolving the
middle lamelle and
MOU ag’ VEMIES. 5.

Inoculations of pure

cultures into healthy Fic. 32.—B. solanisaprus, from agar 24 hours.

Es After Harrison.
plants produced char-

acteristic lesions and the organism was reisolated. Characteristic
enzymic action was observed on placing precipitated enzyme on
slices of potato.

B. sorghi Burr.’ Rods 0.5-1 (usually 0.7) x 1-3 (usually
1.5) w, cylindrical or oval, motile, spore-bearing, non-liquefying.
Colonies on agar, white to pearly. In broth with a white smooth
membrane. :

The bacillus was recognized as the cause of a sorghum blight
by Burrill and this view was confirmed by Kellerman & Swingle
through 1° inoculation experiments.

B. spongiosus A. & R.'® causes gummosis of cherry in Ger-
many.

B. subtilis (Ehr.) Cohn.

Straight rods, often united in threads, 0.7 x 2-8 ». Sporiferous.
Spores central or lying near one pole; germination equatorial.
Flagella, 6-8, peritrichiate; gelatine liquefied; gelatine colonies

50 THE FUNGI WHICH CAUSE PLANT DISEASE

bordered by numerous fine filamentous outgrowths. Growth on
slant agar gray. It is reported as the cause of vegetable rot.1”

Fia. 33.—Muskmelon plant inoculated with a pure culture of B. tracheiphilus. After Smith.

B. tabacivorus Del. is recorded on tobacco stems.®

B. tabificans Del.\* which perhaps belongs to the genus Bac-
terium is reported as the cause of a beet disease in France.

B. tracheiphilus, E. F. Sm. (Group number 222. —03-.)

THE FUNGI WHICH CAUSE PLANT DISEASE 51

Bacillus 1.2-2.5 x 0.5-0.7 uw, variable, actively motile in young
cultures. Capsulated, no spores, peritrichiate. No gelatine
liquefaction. On agar thin, smooth, milk-white. No gas, aérobic
or facultative anaérobic. Milk not curdled. T. D. P. 43°, 10 min.

This pathogen was first reported by E. F. Smith without de-
scription in 1893 “° and more fully in 1895. It is found filling
the vessels of cucurbits, (musk melons and cucumbers) affected
with wilt. Smith produced the disease artificially by puncture
inoculations on the blades of leaves with the white sticky fluid
from infected veins. The inoculated plants showed symptoms of
wilt after four days and sixteen days later the ducts of the vine
were found to be plugged with bacteria. The organism was then
isolated from this artificially infected plant. The cultures thus
obtained were carried by transfers over winter and in December
were used successfully to

infect cucumber plants. Soe ig aismm
Control plants were never . oe ——"
diseased. The ready < iy a

growth of the organism in NS te fot ae

be -
the vessels is attributed to ir au % a ;
the alkalinity of the latter; ee : my ee ay
the failure to grow inthe ‘““s * ,jv oe 1 ty fF Bel

f : y s
parenchyma is attributed " “enke, xe % nYnXe :
to its acidity. se 4G ° sees of P
B. uve Cug. & Mac. is Tepe Leonie Be
reported as causing injury ,y,% Ww v 2% a. ANG:
151 ° a an a e AS we ae,
to young grape clusters. < “et

It is perhaps identical with ,*s. > = AY ter st sy
B. ampelopsore. »—>
B. vulgatus (Fliigge) * “%y--S" as
Mig. This organism is
found as small thick rods Fic. 34.—B. tracheiphilus. After Smith.
with rounded ends, or is
often paired or in chains of four; sporiferous. Gelatine colonies
round, liquefaction rapid. Growth on agar dirty-white.
It has been shown capable of causing rot of various vegetables.
B. zee Burr. is the name applied to a bacillus isolated from
diseased corn plants by Burrill in 1887-1889.%*'** It is often

152

52 THE FUNGI WHICH CAUSE PLANT DISEASE

cited as the cause of a bacterial corn disease but the evidence of
causal relation as well as the identity of the germ are not clear.

B. zinzgiberi Uyeda causes a disease of Zinzibar,° B. sac~-
chari and B. glange are on sugar cane as the possible cause of
sereh.*®

An organism called Clostridium persice-tuberculosis by
Cavara 1 is mentioned as cause of knot on peach trees.

Less known bacterial plant diseases. The literature abounds
in references to what are regarded as cases of plant bacteriose,
cases which as yet rest upon very incomplete evidence. In many
of these bacteria are found in abundance in the diseased tissue
but pathogenicity has not been proved by inoculation nor pure
cultures made. Among such incompletely studied diseases may
be mentioned those of geranium; #18 celery,? onion,’% 1% 1
cucumber," orchard grass,!® lettuce,” '®* (one lettuce disease
is due to a motile rod-shaped organism cultured and inoculated
but not named,1*‘) strawberries," mulberry, hemp,” calceo-
laria.17!

There are also. several obscure bacterial beet diseases; another
cabbage rot due to Pseudomonas; ?”? a decay of apples said by
Prillieux to be due to a Bacillus; *”* the blossom-end-rot of tomatoes
which is perhaps bacterial; !"4 a cyclamen leaf spot; 1” a juniper dis-
ease; 1” a pine gall; 1” an ash bark disease; 18 and an ash canker; 1”
an ivy canker; ® a grape disease; *“ a salsify rot; ®! a carnation
spot; “2 and a banana disease; 8% a gummosis of tobacco; #4 a
disease of tobacco seedlings; '*° also perhaps the serious widespread
mosaic disease of tobacco and an orchid gummosis.**

BIBLIOGRAPHY OF INTRODUCTION
MYXOMYCETES AND BACTERIA * (pp. 1 to 53)

1 Eycleshymer, A. C., Journ. Myc. 7: 79, 1892.

* Nawaschin, S., Flora 86: 404, 1890.

* Woronin, M., Jahrb. f. wiss. Bot. 11: 548, 1878.

* Rowazek, S., Arb. d. Kais. Gesund. Berlin 22: 396, 1905.
5 Maire, R., & Tison, A., Ann. Myc. 7: 226, 1909.

6 Idem., 9: 226, 1911.

7 Kirk, T. W., D. Agr. R., N. Zeal., 365, 1906.

8 Viala & Seuvageau, C. R. 114: 1892 and 120.

9 Idem., C. R., 115: 67, 1892.

10 Massee, G., Ann. Bot. 9: 95.

nt Abbey, Jour. Hort. Soc. London, 1895.

12 Debray, Rev. d. Viticulture, 35, 1894.

13 Behrens, J., Weinbau u. Weinhandel, 33, 1899.

‘4 Ducomet, V., C. R. Ass. Fr. Avanc. Sc. Angers, Pt. 2: 697, 1903.
15 Maublanc, C., Agr. Prat. Pays Chauds. 8: 91, 1908.

16 Osborne, T. G. B., Ann. Bot. 25: 271, 1911.

1 Lagerheim, Jour. Mye. 7: 103, 1892.

18 Johnson, Sci. Proc. Roy. Dublin Soc. N.S. 12: 165, 1909.

*In the bibliographies the usual abbreviations for the states followed by
B. or R. indicate respectively Bulletin or Report of the State Agricultural
Experiment Station, B. P. I. or V. P. P. of the Bureau of Plant Industry or
Division of Vegetable Physiology and Pathology of the United States De-
partment of Agriculture, respectively.

Zeit.= Zeitschrift fiir Pflanzenkrankhciten.

Sc.=Science New Series.

E. 8. R.=Experiment Station Record.

Ann. Myce.= Annales Mycologici.

Soc. M. Fr.=Société Mycologique de France.

Y. B.= Yearbook, U. 8. Department of Agriculture.

C. R.=Compt. Rendu.

C. Bak.=Centralblatt f. Bakt. Par. u. Inf. Ab. IT.

Other abbreviations are those usually employed or readily understood.

All bold face references, will be found in the book bibliography, page 678.

53

54 THE FUNGI WHICH CAUSE PLANT DISEASE

1% Johnson, Econ. Proc. Roy. Dublin Soc. 1, pt. 12, 1908.

2» Wulff, T., Zeit. 16: 203, 1906.

21 Mangin, L., Rev. Hort. Paris 81: 568.

22 Zeit. 13: 267, 1903.

23 Toumey, Ariz. B. 33.

24 Prillieux, E., Ann. Sc. Nat. 6 ser. 7: 248, 1879.

26 Frank, Ber. d. Deut. Bot. Gas. 16: 237, 1898.

* Frank, C. Bak. 5: 98, 1899.

7 Roze, E., C. R. 122: 548, 1896 and 123: 1323.

28 Delacroix, G., Maladies d. Pl. Cult. 19, 1909.

2° Metcalf, H., Neb. R. 17: 69, 1904.

% Vuillamen, C. R. 107: 874, 1888.

21 Busse, W. & V. Faber, F. C., Mit. K. Biol. Anst Land u Forst,
18, 1907.

22 Jones, L. R., N. Y. (Geneva) T. B. 11: 1909.

82 Harding, H. A., and Morse, W. J., N. Y. (Geneva) T. B. 11: 1909.

34 Smith, E. F., V. P. P. 28: 1901.

35 Manns, T. F., O. B. 210: 1909.

38 Pammel, L. H., Ia. B. 27: 1895.

37 Russell, H. L., Wis. B. 65: 1898.

* Smith, E. F., B. P. I. 29: 1903.

* Smith, E. F., C. Bak. 3: 284, 485, 1897.

“ Harding, H. A., Stewart, F. C., and Prucha, M. S., N. Y. (Geneva)
B. 251: 1904.

41 Garman, H., Ky. R. 3: 43, 1890.

“2 Harding, H. A., C. Bak. 6: 305, 1900.

4 Potter, M. C., C. Bak. 7: 282, 1901.

44 Jones, L. R., C. Bak. 14: 257, 1905.

46 Arthur, J. C. & Bolley, H. L., Ind. B. 69: 17, 1896.

4° Barlow, B. B., Ont. Ag. Co. B. 136: 1904.

“ Griffon, E., C. R. Acad. Sci. Paris 149: 50, 1909.

8 Scalia, Agricolt Calabro-Siculo, 1903.

Smith, E. F., V. P. P. 26: 1901.

van Hall, C. J. J., Zeit. 13: 129, 1903.

51 Pierce, N. B., Bot. Gaz. 31: 272, 1901.

52 von Oven, E., C. Bak. 16: 1907.

53 Osterwalder, A., Cent. Bak. 25: 260, 1910.

54 Sackett, W. G., Colo. B. 158: 1910.

86 Smith, E. F., Se. 31: 794, 1910.

% Boyer & Lambert, C. R., Paris 117: 342, 1893.

7 Smith, E. F., Se. N. S. 37: 792, 1910.

BIBLIOGRAPHY OF INTRODUCTION 55

58 Macchiati, L., Malpighia 5: 289, 1892.

59 Beach, 8. A., N. Y. (Geneva) B. 48: 331, 1892.

® Halsted, B. D., N. J. R. 13: 288, 1892.

1 Smith, E. F., Proc. A. A. A. 8. 288: 1897.

62 Smith, E. F., Se. 17: 456, 1903.

63 Rorer, J. B., Mycoligia 1: 23, 1909.

64 Pierce, G. P., Proc. Cal. Acad. Sc. 3rd Ser. Bot. 2: 295, 1902.
6 Smith, E. F., B. P. I. 181: 25, 1908.

% Malkoff, K., C. Bak. 16: 664, 1906.

67 Stewart, F. C., N. Y. (Geneva) B. 130: and R. 16: 401, 1897.
« Smith, E. F., Proc. A. A. A. S. 422: 1898.

® Smith, E. F., C. Bak. 10: 745, 1903.

Smith, E. F., Se. 17: 458, 1903.

7 van Hall, C. J. J., Bij. t. Kenn. Bak. Plonet 142, 1902.

72 Smith, E. F., and Townsend, C. O., Sc. 25: 672, 1907.

73 C, Bak. 20: 89.

™ Townsend, C. O., Sc. 29: 273, 1909.

7 Smith, E. F., Phytopathology 1: 7, 1911.

7% Smith, E. F., Brown, N. A., and Townsend, C. O., B. P. I. 213, 1911.
7 Cobb, N. A., New So. Wales, Dept. Agr. 1893.

7% Smith, E. F., C. Bak. 13: 726, 1905.

7” Brown, Nellie A., Sc. 29: 914, 1909.

80 Jamiesson, Clara O., Sc. 29: 915, 1909.

81 Delacroix, G., Ann. Inst. Nat. Agron. 2, Ser. 6: 353, 1906.
82 Burrill, T. J., Trans. Ill. Hort. Soc. 114, 1877.

83 Idem, 80, 1878.

* Burrill, T. J., Proc. A. A. A. S. 29: 583 and Am. Nat. 15: 527.
85 Arthur, J. C., N. Y. (Geneva) R. 3: 1884.

86 Arthur, J. C., Proc. A. A. A. 5. 34: 1885.

87 Arthur, J. C., Bot. Gaz. 10: 343, 1885.

® Arthur, J. C., Proc. Phila. Acad. Science 331, 1886.

8 Jones, L. R., C. Bak. 9: 835, 1902.

% Paddock, W., Col. B. 84.

21 Detmers, F., O. B. Ser., IV: No. 6, 129, 1891.

22 Whetzel, H. H., N. Y. (Cornell) B. 236, 1906.

93 Burrill, T. J., Trans. Ill. Hort. Soc. 147, 1881.

94 Brizi, U., C. Bak. 3: 575, 1897.

% Halsted, B. D., N. J. B. Q: 1892.

%* Rankin, W. H., Special Crops. N. 8. 9: 94, 356.

7 Uyeda, Y., see 96.

% Townsend, C. O., B. P. I. 60: 1904.

56 THE FUNGI WHICH CAUSE PLANT DISEASE

* van Hall, C. J. J., Diss. 1902.

10 Busse, W., Zeit. 7: 65, 1897.

101 Delacroix, C. R. 140: 1356, 1905.

102 Jones, L. R., C. Bak. 7: 12, 1901.

103 Jones, L. R., Vt. R. 13: 299, 1901.

104 Harding & Stewart, Sc. 16: 314, 1902.

105 Peglion, V., Zeit. 7: 81.

10 Smith, E. F., Se. 19: 416, 1904.

107 Hegyi, Kizer Kozlem 1: 232, 1899.

108 Stedman, J. M., Ala. B. 55: 1894.

19 Prillieux & Delacroix, Rev. Int. d. Vit. D’Oenol, 1894.

110 Heinz, Cent. f. Bakt. 5: 535, 1889.

111 Voglino, P., An. R. Ac. d. Agr. d. Torino 46: 1903.

u2 Hegyi, D., Kiser. Kézlem 2: 1899, No. 5235.

13 C, R. 140: 678, 1905.

114 Pethybridge, & Murphy, P. A., Nature (London, 1910), 296,
No. 2148.

115 Giddings, N. J., Vt. B. 148: 1910.

us Linhart I., Zeit. 10: 116, 1900.

117 Uyeda, Y., Bull. Imp. Centr. Agric. Sta. 1: 39, Dec., 1905.

u8 Uyeda, Y., C. Bak. 13: 327, 1904.

u9 Smith, C. O., Bot. Gaz. 42: 302, 1906.

120 Harrison, F. C., C. Bak. 13: 46, 1904.

121 Harrison, F. C., Se. 16: 152, 1902.

122 Harrison, F. C., Ont. B. 137: 1904.

123 van Hall, C. J. J. Zeit. 13: 129, 1903.

124 Uyeda, Y., Bot. Cent. 17: 383, 1907.

225 Voglino, P., Bot. Cent. 274, 1893.

128 C. Bak. 5: 33, 1899.

127 Appel, O. Arb. aus. Biol. Abt. Kaisel Gesundtheilamt 3: 364, 1903.

12 Smith, E. F., Sc. 31: 748, 1910.

129 Brizi, U., Atte. Cong. Nat. Ital. Milan, 1907.

120 Smith, R. G., Proc. Lin. Soc. N. S. Wales 29: 449.

141 Halsted, B. D., N. J. R. 12.

132 Halsted, B. D., N. J. R. 4: 267, 1891.

133 Halsted, B. D., Miss. B. 19: 1892.

4 Burrill, T. J., Proc. 11th Ann. Meeting Soc. Prom. Agr. Sci. 21, 1890.

135 Thid. 29, 1891.

136 Smith, E. F., V. P. P. 12: 109, 1896.

137 Smith, E. F., Proc. A. A. A. S. 191, 1895.

138 Stevens, F. L., Press Bull. N. C. 11: Aug. 1903.

BIBLIOGRAPHY OF INTRODUCTION 57

139 Stevens, F. L. and Sackett, W. G.,,N. C. B. 188: 1903.

140 Smith, E. F., B. P. I. 141, Pt. II, 1909.

441 Delacroix, G., C. R. 133: 417, 1030, 1901.

142 Kramer, If., Oest. land. Cent. /: 11, 1891.

148 Harrison, C. Bak. 17: 34, 1907.

144 Burrill, T. J., Proc. Am. Soc. Mic. 1888.

145 Kellerman, W. A. and Swingle, Kan. R. 1: 1888.

140 Aderhold and Ruhland, Arb. d. Kais. Biol. Anst f. Land. u. Forst.
: 1907.

M7 van Hall, C. J. J. C. Bak. 9: 642.

18 Delacroix, C. R. 37: 871, 1903.

149 Smith, E. F., Bot. Gaz. 18: 339, 1893.

150 Smith, E. F., C. Bak. 1: 364, 1895.

151 Macchiati, L., Rev. inter d. Vit. et D’Oenol. 1: 129, 1894.

182 van Hall, C. J. J. C. Bak. 9: 642, 1902.

153 Burrill, T. J., Billings, the corn stalk disease in cattle investigation
163, 1889.

154 Burrill, T. J., Ill. B. 6: 1889.

155 Sta. Sperim Agr. Itat. 30: 482, 1897, also Zeit. 8: 37.

156 Stone, G. E., and Smith, R. E., R. Mass. (Hatch) 12: 57, 1900.

187 Stone, G. E., and Monahan, N. F., R. Mass. Sta. 19: 164, 1907.

158 Galloway, B. T., J. Myc. 6: 114.

199 Stewart, F. C., N. Y..(Geneva) B. 164, 1889.

100 Halsted, B. D., N. J. R. 11: 1890.

11 Stone, G. E., and Monahan, N. F., R. Mass. Sta. 19: 161, 1907.

182 Rathay, E., Sitz, K. A. K. Wiss. Wien 597, 1899.

163 Jones, L. R., Vt. R. 6: 1892.

164 Fawcett, H.8., Fla. R. 1908, 80.

165 Detmers, O., B. 4: 1891.

188 Voligno, P., Zeit. 17: 150.

187 Stone & Smith, Mass. R. 1896.

188 Smith, R. E., Mass. R. 9: 59, 1897.

1 Cavara, Sta. Spm. Agr. ital. 30: 482, 1897.

170 Peglion, Zeit. 7: 81, 1897.

7” Halsted, B. D., N. J. R. 430, 1893.

172 Spieckermann, Land. Jahr. 31: 155, 1902.

173 Prillieux, B. Soc. Bot. d. France 33: 600, 1896.

74 Earle, F. 8., Ala. B. 108: 19, 1896.

175 Prillieux, E. & Delacroix, G., C. R. 118: 668, 1894.

176 Cavara, B. Soc. Bot. Ital. 241, 1898.

17 Tubeuf, Nat. Zeit. Forst und Land. 9: 25, 1911.

58 THE FUNGI WHICH CAUSE PLANT DISEASE

18 Jour. Bd. Agr. London, 17: 478.

179 Noack, F., Zeit. 3: 191, 1893.

10 Lindau, Zeit. 4: 1, 1894.

181 Halsted, B. D., N. J. R. 11: 351, 1890.

182 Woods, A. F., Sc. 18: 537, 1903.

183 Rorer, J. B., Proc. Agr. Soc. Trinidad and Tobago, 10: No. 4.

184 Honing, J. A., Med. Deli. Medan 4: 24.

185 Comes, O. Atti. d. R. Inst. d’Incor. d. Napolo, 4: 6, 1893.

16 Potter, Gard. Chron. Mch. 6, 145, 1909.

187 Schwartz, E. J., Ann. Bot. 25: 791, 1911.

188 Nemec B., Ber. d. deut. Bot. Gez. 29: 48, 1911.

18 Johnston, J. R., Phytop. I: 97, 1911.

1 Payarino, G. L., Atti R. Acad. Lincei Cl. Sci. Fis. Mat. e. Nat.
6: 355, 1911.

191 Boyer & Lambert, C. R. 128: 342, 1893.

12 Pavarino, L., Riv. d. Pat. Veg. 5: 65, 1911.

183 Halsted, B. D., N. J. B. Q., also R. 1891, 558.

194 Cavara, B. Soc. Bot. Ital. 241, 1898.

15 Stevens, F. L., N. C. R. 31: 74, 1908.

196 Hori, 8., C. Bak. 31: 85, 1911.

197 Hori, 8., B. Imp. Cent. Ag. Ex. Sta. Nishigahara, 1910.

198 Tdem., 11, 1911.

19 Marchand, E. F. L., C. R., heb. d. seans. d. l’ac. d. Sc. 140: 1348.

2 Stewart, F. C., N. Y. (Geneva) R. 14: 525, 1895.

201 Kirk, N. Zeal. R. 13: 427.

202 Jones, L. R., Vt. B. 66: 1898.

203 Halsted, B. D., N. J. R. 306, 1896.

24 McCulloch, L., B. P. I. 225: 1911.

206 Orton, W. A., Farm B. 41: 309, 1907.

206 Uyeda, Y., C. Bak. 17: 383, see also extensive Japanese publica-
tion later by Uyeda. i

207 Sackett W. G., Col. B. 177: 1911.

208 Bull. No. 2, 1896, p. 76, Torr. Bot. Cl.

2 Jour. Am. Pub. H. Assn., Jan. 1898: 60; Recommendation for the
study of Bacteria. See also Rept. Soc. Am. Bact. Meeting of 1907.

210 Pavarino, L., Rend. d.r. Ac. d. Lincei, Classe Scienze, 20: 161, 1911.

DIVISION III
EUMYCETES. TRUE FUNGI (p. 3) 727 192,28. 29, 45-68

The Vegetative Body is devoid of chlorophyll and typically
consists of a more or less branched filament of apical growth, the
mycelium. This mycelium may be cut into cells by partitions
(septa) or may be continuous, i. e., without septa. The cells of
the septate mycelium do not differ essentially from typical plant
cells except in the absence of chlorophyll. They consist of masses
of protoplasm, the protoplasts, bearing vacuoles and are more or
less rich in oils, acids,
gums, alkaloids, sug-
ars, resins, coloring
matter, etc., varying
in amount and kind
with the particular
species and condition
of the fungus. The
protoplast is covered
by a cell wall which
consists of cellulose
though often of a
special quality known {
as fungous cellulose.

The protoplast bears

j * Fic. 35.—Showing a septate mycelium within host
one, Chane fungi cells. After Stevens and Hall.

two or more nuclei.

The vacuolation of the protoplasm, the mode of branching of the
cells, their color, dimensions, etc., are in some cases quite charac-
teristic.

In one class, the Phycomycetes, the active vegetative mycelium
possesses no septa except such as serve to cut off the sexual or
other reproductive organs or such as are found in senility. The

59

60 THE FUNGI WHICH CAUSE PLANT DISEASE

protoplasm is therefore continuous throughout the whole plant
body and may be regarded as constituting one cell though it may
be of great extent and bear very numerous nuclei. Such multi-
nucleate cells, coenocytes, may be regarded as cell complexes with
the walls omitted.

In one comparatively small order, the Chytridiales, there is
often no filamentous mycelium and the vegetative body consists
merely of a globular, irregularly spherical or amceboid cell. Such
forms are thought by some mycologists to be degenerate, to have
in remote time possessed a mycelium which has been lost owing to
the present simple mode of life of the fungus, the needs of which
no longer call for a filamentous body, while others! find here
primitivé forms of Phycomycetes, and trace their phylogenetic
connection with the higher orders of the class.

Reproduction.

Vegetative. Most mycelia, if cut in bits and placed in suitable
environment, continue to grow, soon equaling the parent mycelium

y in size if abundant nourishment obtains. Bits
of diseased tissue, bearing mycelium, thus con-
stitute ready means of multiplication and dis-
persal.

Asexual Spores. A spore is a special cell set
aside to reproduce the plant. An asexual spore
is a spore not produced by a sexual process.
Manifold forms of asexual spores exist among
the fungi. In some of the simplest cases, bud-
like out-growths (gemme) appear on the myce-
lium; or portions of the mycelium itself are cut
off by partitions and the protoplasm inside
gathers into a mass and protects itself by a
firmer wall than that of the mycelium, chla-
mydospores. In other cases special branches,
F 0 oo hyphe, are set apart for the purpose of bearing

Qidium. After spores. If the spores are cut off from the tip of

: the branch they are known as conidia or conidio-
spores, and the branch bearing them is a conidiophore. Conidia
may be borne singly or in false clusters caused by the youngest
pushing the older conidia aside; frequently they are produced in

THE FUNGI WHICH CAUSE PLANT DISEASE 61

chains, catenulate, Fig. 36, owing to the development of one spore
below another before the elder spore is shed. Conidia may be
either simple, composed of one cell, or compound, composed of two
or more cells. In compound spores each cell is at least potentially
a spore and can germinate under favorable conditions and per-
petuate the species. In many compound spores the germinating
function is sacrificed by one or more of their component cells.

Conidiophores may consist of loosely branching, rather long
hyphe, or they may be short, innate, and in close clusters forming
distinct spore bearing
spots. Fig. 371. Such
sporiferous spots when
naked are called acer-
vuli. Often the conid-
iophores are roofed over
with a net-work of
woven fungous threads
thus constituting a
special spore-bearing
structure, the pycnidium.
Figs. 37, 335. Conidio-
phores may be solitary
or grow together in bun-
dles or branch loosely as
in Fig. 383.

The basidium, Fig. 38,
is a special kind of sporo-
phore bearing at its Fic. 37.—Conidia borne in a_pycnidium. After

Quaintance and Shear.
apex usually four, or
two, small projections, sterigmata, each of which produces one
spore, for distinction called a basidiospore.

Some fungi bear the spores loose inside of the swollen tips of
sporophores as in Fig. 68. The spore bearing structure is then
called a sporangium and its stalk a sporangiophore. The ascus
is another spore bearing structure. In it the spores are borne very
much as they are in the sporangium but usually of definite num-
ber, 1, 2, 4, 8, 16, etc., eight being the most common number.
Asci may be naked or covered, scattered or collected in groups.

62 THE FUNGI WHICH CAUSE PLANT DISEASE

When covered, the chamber in which they are borne is called a
perithecium, Fig. 39; when on an open disk the disk is called an
apothecium, Fig. 101.

According to their length of life spores are classed as: 1. rest-
ing spores whose function is to tide over unfavorable conditions,
hence the common name
“winter spore,” and
in contradistinction: 2.
“Summer spores” which
are produced in abun-
dance in warm weather,
germinate immediately,
and can ordinarily live
but a short time.

In some species the
spores that are to func-
tion in water possess cilia,
and the power of motion.
These are zo0spores or
swarm spores, Fig. 44.

At sporing time many kinds of fungi produce special structures
for the bearing of spores. The fungous threads interweave to
form a firm, or even a densely solid, mass and constitute a false
parenchyma. Such are the stalks and caps of the mushrooms and
of the shelving toadstools, the skin of the puff ball, ete. A cross
section of such a structure appears much as a true parenchyma, a
longitudinal section shows it to be merely a mass of interwoven
fungous threads.

Sexual Spores are formed by the union of sexual elements,
gametes. They are most conspicuous among the Odmycetes
where the antheridium carries the sperms into the odgonium,
fertilizes the odsphere and produces an odspore. Figs. 53-55.

As a rule the sexual spores are produced toward the end of the
vegetative period of the fungus. The asexual spores are produced
earlier and for a longer period. Sexual spores are commonly
resting spores.

Germination of spores. Under suitable environment mature
spores germinate and eventually give rise to vegetative bodies

Fie. 38.—Basidia of various ages. After Schenck.

THE FUNGI WHICH CAUSE PLANT DISEASE 63

similar to that of the parent. The most usual mode is for the
mycelium to rise directly from the spore. In other instances the
spores produce zoéspores which migrate, come to rest, then develop
a mycelium. In still other cases a short mycelium, promycelium,
is formed and from this small conidia, sporidia, are made.
Figs. 217, 240. These conidia give direct rise to the mycelium.
Spores of some species may by gemmation lead a more or less
prolonged existence without return to the mycelial stage.

Heat and Moisture Relation. Like all living things these
organisms cannot develop without heat and moisture. The
necessary degree of each varies with different species. Some

g ascospore
Nee ninto

Fic. 39.—A perithecium with asci. After Reddick.

species are strictly aquatic, and must be surrounded with water;
others can grow in comparatively dry situations. Generally
speaking, however, dampness favors fungous development, and
the growth of most fungi is more vigorous in a damp atmosphere
than inadrier one. Similarly moderate warmth, as that of summer
heat, favors fungous growth. Humidity and warmth combined
are proverbial as producers of mold and mildew. So conspicuous
is the coincidence of these conditions with fungous growth, that
in the minds of many a warm damp air is the cause rather than the
condition of fungous development.

Respiration with the fungi as with other plants and animals
consists in oxidation, involving intake and consumption of oxygen
accompanied by the giving off of carbon dioxide and water, and

64 THE FUNGI WHICH CAUSE PLANT DISEASE

since no photosynthesis occurs, this process is never masked as it
is in the case of the chlorophyll-bearing plants.

In nutrition requirements there is great diversity; but in all
cases carbon must be taken from some organic source. Starch,
sugar, cellulose and kindred compounds are frequent sources of
the carbon food supply. Nitrogenous foods are, generally speaking,
not required in such abundance by the Eumycetes as by the
bacteria and advantage may frequently be taken of this fact in
isolating the fungi from bacteria by growing them on media poor
in nitrogen, in which case the fungi often outgrow the bacteria.

The color of the fungi is determined largely by the constitution
of the media upon which they grow.” * * 4

Many fungi exhibit a peculiar hetercecism, that is, part of their
life cycle is passed through upon one host, part of it upon another
host, even of very distant botanical kinship. Thus among the
rusts; in one instance part of the life cycle is upon the apple, the
remainder upon the cedar tree. Fungi also exhibit polymor-
phism, i. e., in one stage they exhibit one spore form and in an-
other stage another spore form totally different. In this way
several apparently quite distinct types of spores and sporiferous
structures may belong to the same species.

Classification of Fungi.® 7 1% 31-3528 The true fungi in them-
selves constitute a very large group made up of diverse forms, many
of which are as yet little known. Any satisfactory system of classi-
fication is impossible until much more knowledge is gotten regard-
ing their morphology, cytology, life histories and especially their re-
lations to their hosts. According to present knowledge they com-
prise very numerous species distributed in three classes as follows:

Key to Ciasses or Eumycetes
Mycelium continuous in vegetative

BURBS sess shee ie avi end a Class 1. Phycomycetes, p. 65.
Mycelium septate
Spores in asci................0.... Class 2. Ascomycetes, p. 113.
Spores on basidia* ............... Class 3. Basidiomycetes, p. 298.

Not as above; spores on conidio-
phores, naked, or in pycnidia;
or spores quite unknown...... Fungi Imperfecti, p. 475.
*In the rusts and smuts the promycelium is regarded as a basidium.

THE FUNGI WHICH CAUSE PLANT DISEASE 65

Class I. Phycomycetes, Alga-like Fungi (p. 64)

The Phycomycetes are characterized by the absence of septa in
the mycelium except in sporing branches, where they occur to
cut off the spore-bearing cells or the gametangia, and in old fila-
ments. The body is multi-nucleate and sexual spores as well as
asexual ones are usually, though not always, produced. Some of
the Phycomycetes live in water and possess zodspores, others are
parasitic on land plants and bear conidia or sporangia. These
may germinate either by germ tubes or by zodspores. The char-
acteristic fertilization consists of a union of two gametes which
may be like in character (isogamy) or unlike (heterogamy). If
the sexual organs are unlike the receptacle which bears the sexual
spores is called the o6gonium, its eggs before fertilization odspheres,
and the spores odspores. The receptacle bearing the fertiliz-
ing gamete is the antheridium, and the fertilizing elements
are the sperms. The sperms may be motile and swim or creep
into the odgonium or the antheridium may develop a tube leading
into the oégonium through which the fertilizing nuclei pass. In
some forms which, by their sexual or asexual spores, show relation
to the Phycomycetes the mycelium is wanting and the vegetative
body is reduced to a single spherical or amceboid cell, which fre-
quently lives in a purely parasitic manner entirely imbedded in
the protoplasts of its host. This mode of life constitutes the
strictest kind of parasitism inasmuch as the fungus derives its
nourishment from the still living host cell.

Key To ORDERS or Phycomycetes

Sexual spores when present heteroga-
MOUS sachs oN ea vecde a ee eee Subclass I. Oomycetes, p. 66.
Conidia absent; sexual spores and z06-
sporangia only
Mycelium poorly developed, frequently
reduced to a single cell
Fruiting mycelium a single cell, or a
group of cells in a sorus, forming
either asexual resting spores or
sporangia from the entire proto-
plasmic mass..................... 1. Chytridiales, p. 66.

66 THE FUNGI WHICH CAUSE PLANT DISEASE

Fruiting mycelium multicellular,
some cells forming sporangia,
others producing gametes and
OUSPOLES 55 Gv sai ec weeks 2. Ancylistidiales.
Mycelium well developed
Fertilization by motile sperms. ... 3. Monoblepharidiales.
Fertilization eee an anther-
idial tube . vesssseeeesss. 4, Saprolegniales, p. 74.
Conidia present. . Lasied 5. Peronosporales, p. 77.
Sexual spores isoenious, formed ie the
union of similar gametes..Subclass II. Zygomycetes, p. 101.
Asexual spores several, in sporangia... 6. Mucorales, p. 102.
Asexual spores solitary, conidia....... 7. Entomophthorales, p. 107.

Of these orders the Ancylistidiales which are parasitic upon
Algz, and the Monoblepharidiales which are saprophytic will not
be considered further.

Subclass Oomycetes (p. 65)

In the Odmycetes there is pronounced difference between the
male and female sexual organs. The odgonium is comparatively
large, and contains one or more large passive eggs (odspheres),
which are fertilized by sperms, differentiated or not, which either
swim to the odgonium by cilia, creep to it, or are carried to it by
a fertilizing tube. Odspores are in some species produced fre-
quently and abundantly while in others they are entirely unknown.
The asexual reproduction is by either conidia or sporangia.

Chytridiales (p. 65)

The members of this order are the simplest of any of the Phy-
comycetes. Many of them are single, more or less globose, undif-
ferentiated cells, others have a more or less prominent haustoria-
like mycelium, while but few have any approach to a true myce-
lial development. Most are intracellular parasites; a few of the
more highly developed genera are intercellular parasites. With
few exceptions reproduction is entirely asexual, all spores being
formed directly from the vegetative cell. Zoésporangia and thick-

THE FUNGI WHICH CAUSE PLANT DISEASE 67

walled resting spores are produced. The zodspores have either
one or two cilia. There are over forty genera and two hundred
species. The majority of the species are inconspicuous parasites
of alge and infusoria; but some genera, like Synchytrium and
Urophlyctis, produce conspicuous sori and even cause hyper-
trophy of land plants.

Key To Famiuies or Chytridiales

Spores all asexual, or rarely formed by the
union of free-swimming gametes
Mycelium none
Sporangia solitary.................. 1. Olpidiace, p. 67.
Sporangia grouped into sori.......... 2. Synchytriacea, p. 69.
Mycelium present
Mycelium of delicate, evanescent haus-
toria-like strands
Mycelium limited, sporangia ter-

Mina. ccc aw ee vax wees yews 3. Rhizidiacee.
Mycelium extended, sporangia ter-
minal or intercalary.......... 4. Cladochytriacee, p. 72.
Mycelium of permanent hyphe...... 5. Hypochytriacee.
Spores both sexual and asexual
Gametes hetrogamous. ................ 6. Odchytriacee, p. 73.
Gametes isogamous. ...............005 7. Zygochytriaceee.

Four only of these families have parasitic representatives on
higher plants in America, the others being chiefly parasitic on
alge and infusoria.

Olpidiaceze

This family which contains the simplest members of the order
has no mycelium; the entire plant body consists of a single more
or less globular or elliptic cell which never divides, but at maturity
forms either a zodsporangium or an asexual resting spore which
after a period of rest gives rise to swarm spores. All the species
are endobiotic. The family contains some forty species but few
of which are of economic importance.

68 THE FUNGI WHICH CAUSE PLANT DISEASE

Key To Genera or Olpidiacee

Vegetative body ameeboid...........-.-- 1. Reessia.
Vegetative body of definite form
Sporangia free in the cells of the host
Sporangial membrane very delicate,
evanescent. ...... Sahih Ga atte Mateus 2. Spheerita.
Sporangial membrane firm, swarm
spores escaping by a definite open-
ing
Sporangium globular or ellipsoid
Sporangium with only one or two
openings
Swarm spores uniciliate
Vegetative cells globose or sub-

globose 3. Olpidium, p. 68.
Vegetative cells stellate 4. Asterocystis, p. 69.
Swarm spores biciliate 5. Olpidiopsis.
Sporangium with several openings 6. Pleotrachelus.
Sporangium elongate ............. 7. Ectrogella.
Sporangial membrane united to the wall of
the host cell..............2...000. 8. Pleolpidium.

Olpidium A Braun

In this genus a single swarm spore invades the cell of the host
and develops in its pro-
toplasm. Later a cell
wall forms and the vege-
tative body changes into
a zodsporangium which
develops a neck. This
reaches to the outside
of the host even though
the fungus be developed
several cells below the
surface. The uniciliate

Fie. 40.—O, brassice; right, three sporangia in 20 6spores pass out
a cell; left, resting spores. After Woronin. through this neck to

make their escape. Thick-walled resting spores are also formed.

THE FUNGI WHICH CAUSE PLANT DISEASE 69

There are some twenty-five species most of which live as para-
sites on alge, worms, pollen grains, etc.

O. brassice (Wor.) Dang.‘ is parasitic on quite young cabbage
seedlings, sometimes infecting cells deeply seated in the host.
The same or a nearly related species also attacks tobacco and
several weeds. :

Sporangia solitary or several in each infected host cell, globular;
zodspores numerous, globose, uniciliate; resting spores globose,
with a wrinkled epispore which gives them more or less of a star-
like appearance. Fig. 40.

Asterocystis de Wildeman (p. 68)

There is a single species, A. radicis d. Wild.’ which differs from
Olpidium in its stellate vegetative cell and the absence of the tube
for the escape of the zodspores, this being accomplished by the
breaking away of the tissues of the host. The fungus attacks the
roots of various plants, notably flax, Brassica and other crucifers,
Plantago, Veronica and numerous grasses, producing chlorosis.
It has not been reported from America.

A Chytridiaceous fungus of unknown genus thought to stand
near the Olpidiacee and Synchytriacee has been described by
Horne’ as the cause of an Irish potato disease.

Synchytriacez (p. 67)

The infecting zodspore invades the host cell and becomes
parasitic upon the still living protoplasm. Hypertrophy of this and
adjacent host cells is usually induced, resulting in the formation of
a small gall around the infected cell. This gall is often colored
and bears a superficial resemblance to a rust sorus. The parasite
enlarges until it occupies nearly the whole of the host cell. In
Synchytrium the one nucleus then enlarges and divides to produce
very numerous nuclei.* 1412 The whole mass then divides
into segments regarded as sporangia, and each sporangium divides
into numerous uninucleate parts, each of which develops into a
zodspore. In some species development is arrested before the
division of the primary nucleus and the protoplast becomes
spherical, invests itself with a thick wall and becomes a resting

70 THE FUNGI WHICH CAUSE PLANT DISEASE

spore. (Fig. 42.) After a more or less protracted period of rest
this produces zodspores.

The family includes some fifty species, all of which, except two
small genera, are parasitic upon land plants.

Key To GENERA or Synchytriaceze

Zoésporangia formed by direct division of
the entire plasma of the young fruiting
body.

Swarm sporangia completely filling the
host cell, membrane united to the

wall of the host cell.............. 1. Rozella.
Swarm sporangia lying free in the host cell
Parasitic on alge ............2..-55- 2. Woronina.
Parasitic on land plants. . ........ 8. Woroniella.

Zoésporangia formed by divieion af an ini-
tial cell to forma sorus of sporangial cells.
Sporangia formed directly from the full-
grown plant body................. 4. Synchytrium, p. 70.
Sporangia formed by the division of a thin-
walled mother cell after its escape
from the plant body. .............. 5. Pycnochytrium, p. 72.

Synchytrium de Bary & Woronin

Upon reaching maturity the plant body develops directly into
asporangial sorus. Both zodsporangia and winter spores present.

Fic. 41.—Showing nucleus in Sy eerisae After Stevens.

S. endobioticum (Schilb.) Perc., the cause of a very serious wart
disease of the potato, was originally described as Chrysophlyctis
endobioticum by Schilberszky '* and transferred to Synchytrium
by Percival.!® It invaded America about 1909.1! It was reported
from Africa by Zimmermann.!®

THE FUNGI WHICH CAUSE PLANT DISEASE 71

In summer the resting spores which average about 52 u in diam-
eter are found in abundance in the host cells near the surface, few
in the outer layer, more below
down to the sixth or eighth
row of cells. Each resting
spore contains several hun-
dred roundish zoéspores which
measure 2-2.5 wu. In spring
the resting spores germinate,
freeing numerous pear-shaped
uniciliate zodspores, which at
first swim with a jerky motion

5 : ; but soon become ameeboid.

Fr, 42 A. soption showing sporangia °F ‘The summer sporangia may

ameeboid. After Percival. germinate without protracted

rest, and also give rise to zoéspores. Another type of sporangium

consists of thin sacs, produced singly or two to five in a sorus,

each bearing numerous zodspores somewhat smaller than those
from the first type of sporangia.

The zodspores, says Percival, enter the potato apparently in
the amceboid state in bud tissue of rhizomes and in the “eyes” of
young tubers. Usually only one zoéspore enters each cell but
occasionally more may do so. Crushed sporangia produced
characteristic warts in three to four days when placed on suscep-
tible parts. Successful inoculations were also made by Salmon and
Crompton.’ The cytology has been studied by Percival.* The
full grown tumors vary in size from that of a
pea to a hen’s egg, and represent metamor-
phosed branch systems.

S. vaccinii Thomas '” is the cause of a
disease of the cranberry and related hosts. It
forms numerous, small, reddish galls in which,
deeply embedded, are the sori.

S. papillatum Farl.”° occurs on Alfilaria in

F i Fic. 43.—Gall of S.
California. vaccinii. After

Other species of Synchytrium arefound upon = Shear.
dandelion, Hnothera, Geranium, Amphicarpa, Ornithogalum, clo-
ver, elm, etc., but as yet are not of economic importance in America.

72 ‘THE FUNGI WHICH CAUSE PLANT DISEASE

Pycnochytrium Schréter (p. 70)

Only resting spores are known. In germination their proto-
plasmic contents emefges and forms a sporangial sorus.

P. anemones (D. C.) Schr. is common on various species of
Anemone; P. globosum (Schr.) Schr. on the violet, blackberry,
maple, etc. None of the species are of any considerable economic
importance.

Cladochytriacez (p. 67)

A branching mycelium runs through or between the cells of
the host drawing nourishment from many cells. Sporangia are
either apical or intercalary and contain uniciliate zodspores.
Resting spores are also produced. There are about a half dozen
genera and some thirty species.

Key to GENERA oF Cladochytriacez

Resting spores only known. .............. 1. Physoderma.
Swarm spores only known
Intracellular and endophytic
Swarm spores at first ciliate, becoming
ameeboid.................... 0. 2. Cladochytrium, p. 72.
Swarm spores not becoming ameeboid 3. Pyroctonium, p. 73.
Living free among the hosts
Sporangia opening by a pore. ........ 4. Ameebochytrium.
Sporangia opening by a lid........... 5. Nowakowskiella.

Cladochytrium Nowakowski?!

The genus contains about ten species of intercellular parasites
with branched mycelial threads. The zoésporangium is globose,
and opens by a distinct mouth which develops a tube for the

escape of the zodspores much as does Olpidium. Resting spores
are not known.

THE FUNGI WHICH CAUSE PLANT DISEASE 73

The most important species are C. tenue Nowak. on Acorus
and Iris; C. graminis Bisg.™® on various grasses, C. viola Berlese
on violets.”?

C. viticulum Pru.** and C. mori Pru.?4 have been described on
grape and mulberry, but further study is very desirable.

C. brassice E. & B.*°is described from dead leaves of cab-
bage.

C. cespitis G. & M.” occurs in France on Lolium.

Pyroctonium sphericum Pru.” was reported in 1894 as the
cause of wheat disease in France but has not since been
found.

Oschytriacez (p. 67)

The plant body is either an undifferentiated cell or a well de
veloped mycelium; reproduction by means of asexual swarm
spores and sexual resting spores. Of the three genera only one
is of economic importance.

Key to Genrera or Oochytriacee

Mycelium entirely lacking. .............. 1. Diplophysa.
Mycelium present
Mycelium producing a single gametan-
UUM ct. aati Seay are Me ttalahdie dak aes 2. Polyphagus.
Mycelium producing several gametangia 3. Urophlyctis, p. 73.

Urophlyctis Schroter

Mycelium endophytic, producing zodésporangia on the surface
of the host and thick-walled odspores within the tissues; zodspores
uniciliate. The genus contains some half dozen species all of
which are parasitic on higher plants.

U. leperoides (Sacc. & Trab.) Magnus * * causes “beet root
tumor,’”’ in North Africa and Western Europe. The rootlets of
.the upper portion of the root are attacked and develop tumorous
growths, sometimes as large as a walnut. The infection is super-

74 THE FUNGI WHICH CAUSE PLANT DISEASE

ficial and does not extend to the fleshy tap root. The develop-
ment of the spores is the typical method for the genus, the an-
theridium persisting at the base of the odgonium and retaining its
hyphal connection, while the odgonium becomes free just before
conjugation. The odspores are
subglobose, depressed on one side,
smooth, brown, 45-50 x 30 z.

U. pulposa (Wallr.) Schr., a
closely related species occurs on
the aérial portions of Chenopo-
dium and Atriplex.

U. alfalfze Mag. 137, 138, 141, 142
causes a crown gall of alfalfa in
America and Europe. The dis-
ease is quite similar to that de-
Fic. 44.—Urophlyctis pulposa. a, z06- scribed above for the beet.

formationsd, mature odspores, Aiter U. trifolii (Pass.), Mag., a

acai closely related species, forms
small, glassy, globose pustules on the leaves and petioles of
various species of clover in Europe.

U. hemispherica (Speg.) Syd.*! in South America, U. krieger-
iana Mag.*! in Europe and U. pluriannulata (B. & C.) Farl.®?
in America form Synchytrium-like galls on various umbelliferous
genera. All may belong to the same species. U. major Schr. and
U. rubsaameri Mag. infect respectively the leaves and the roots of
Rumex.

Saprolegniales (p. 66)

Asexual reproduction is mainly by biciliated spores formed in
large numbers in sporangia of various shapes. Sexual spores,
often apogamous, are produced in most genera, much after the
fashion of those of the Peronosporales except that more than one
odspore is frequently formed in one odgonium.}32

The order consists of fifty or more species, mostly parasites
or saprophytes upon aquatic organisms. One species of the genus
Achlya causes serious disease in young fish.

There are three families:

THE FUNGI WHICH CAUSE PLANT DISEASE 75

Key To Famiuies or Saprolegniales

Vegetative mycelium of thick tubular hy-
phx; aquatic; zodsporangia cylindrical
not much thicker than the mycelium
Filaments uniform, not constricted. ..... 1. Saprolegniacer.
Filaments constricted regularly........ 2. Leptomitaces.
Vegetative mycelium of thin hyphz, mostly
parasitic or saprophytic on plant tis-
sues; zodsporangia much broader than
the mycelium, mostly globular. ...... 3. Pythiacee, p. 75.

Dictyuchus Leitgeb.

This genus of the Saprolegniacee contains the only parasite
genus in the first two families.

Sporangia cylindric or clavate, swarm-spores becoming walled
within the sporangium and emerging singly through its lateral
walls. The genus is usually saprophytic but, D. monosporus
Leit. is said by Halsted to be a serious hyacinth enemy.

The other members are mainly on dead or diseased insects or
other animals that are in water or are on diseased alge or in water-
slime.

Pythiacez '%4

This family shows affinity with both the Peronosporales and
the Saprolegniales and is sometimes classed with the one, some-
times with the other. It consists of three genera and about twenty
species characterized by a mycelium of very delicate hyphe which
show no differentiation into sterile and fertile regions. The
species are either aquatic or terrestial; in the latter case they are
soil fungi that grow to maturity upon seedlings. When of aérial
habit the sporangia become conidial in character, that is, they are
detached from the hypha before the discharge of the zodspores.

Zoésporangia elongate.................65 1. Nematosporangium.
Zodsporangia spherical or oval, not linear
Zoéspores formed outside of the zodspo-

76 THE FUNGI WHICH CAUSE PLANT DISEASE

Pythium Pringsheim ** (p. 75)

The mycelium is found in abundance in and about the infected
tissue as fine, branched continuous threads. These, in the terrestial

Fic. 45.—Cucumber seedlings.

Pots 5, 6, and 8 inoculated with Pythium. Pot 7,

Control. After Atkinson.

species, bear conidia on branches which are of the same character
as the mycelium itself. The conidia germinate either by a rupture

Fic. 46.—Fertilization in Py-
thium, showing odgonium,
antheridium, odéspore, peri-
plasm and the o and Q
nuclei. After Miyaki.

of the wall or by the formation of a
beak-like process through which the
protoplasm is extruded, after which it
becomes differentiated into zodspores.
Gemme, very like the conidia in ap-
pearance, are also produced.

The odgonia are quite like the conidia
and gemmz in structure but develop
odspores within. The odgonium is at
first multinucleate but as the odsphere
matures all of the nuclei except one
migrate toward the periphery, the peri-
plasm, or degenerate in the odplasm, re-

sulting at maturity in an uninucleate egg. This is fertilized by
one nucleus from the antheridium. No sperm is differentiated,

THE FUNGI WHICH CAUSE PLANT DISEASE 77

and the contents of the antheridium are carried over to the egg
by a fertilizing tube. Members of the
genus are aggressively parasitic only under
most favorable environmental conditions
of heat and moisture.

Some sixteen species are known.

P. de baryanum Hesse. is most com-
mon **"37 as the cause of ‘Damping Off.’’

Zoésporangia or ‘‘conidia”’ globose to
elliptic, usually papillate, 20-25 »; gemmez
similar in form and size; odspores globose,
hyaline, smooth, 15-18 uy.

P. intermedium de Bary, causes a SOR fy SL ca
“damping off” of fern prothalia,®* P. from. sporangia. After
gracile Schenck, a rot of ginger;* P, Smith and ae
palmivorum Butler, a palm disease in India.* **

Pithiacystis, Smith & Smith (p. 75)

The sporangiophore is delicate; septate; and bears numerous
sporangia sympodially. These produce many biciliate zodspores
internally. No odspores have been
seen. Only one species is known.

P. citriophora Sm. & Sm.* ”

Parasitic on lemons, the sterile
mycelium inhabiting the rind;
spores normally formed in the soil
near infected fruits; sporangia ovate
or lemon-shaped, papillate, 20-60 x
Fro, 48.—Sporangiophores and spe- 30-90 u, averaging 35 x 50 u, borne

Smith and Smith. sympodially; zoéspores 10-16 4,
at first elongate, becoming rounded and bearing two lateral cilia.

This was first noted by Smith and Smith ® “ on rotting lemons
in California. Infection by pure cultures proved that the fungus
was the true cause of the rot.

Peronosporales (p. 66)

These fungi constitute an order characterized by a richly
developed, branching, non-septate, usually coarse, mycelium of

78 THE FUNGI WHICH CAUSE PLANT DISEASE

strictly parasitic habit. The mycelial threads in most genera
wander between the host cells and draw nutriment from them by
short branches, sucking organs (haustoria), (Fig. 49) of various
forms, which penetrate into the victimized cell. In one genus
only, Phytophthora, does the mycelium grow directly through cells.
Two kinds of spores are produced, sexual and asexual. The
sexual spores result from the union of two
unlike gametes, the egg (odsphere) and
sperm, borne respectively in the oégonium
and antheridium. Each odgonium bears a
solitary odsphere. Fertilization is accom-
plished by means of a tube from the anther-
idium and penetrating into the oégonium.
Pen ee ee eran The sexual spores are thick walled, re-

Peronospora. After sistant, and usually require a long time to

apt reach maturity. They are, therefore, often
called “resting spores.”’ In germinating the sexual spores pro-
duce either germ tubes or develop directly into zodsporangia.
The aséxual spores are conidia. They are borne on conidio-
phores which arise from the mycelium and which may be short
or long, simple or branched, subepidermal or superficial accord-
ing to the habit of the species. The conidia in various genera
germinate by three methods, (1) a germ tube is sent out by
the conidium, (2) the entire protoplasmic contents of the spore
passes outside the spore wall and then forms a germ tube, or
(3) the conidium by internal division breaks up into zodspores.

Key To Famities or Peronosporales

Conidiophores, short, thick, subepidermal,

conidia catenulate.................. 1. Albuginacee, p. 78.
Conidiophores, longer, superficial, simple or

branched, conidia not catenulate...... 2. Peronosporacee, p. 82.

Albuginaceze

There is a single genus, Albugo (Persoon) Roussell. This genus
of about fifteen species is entirely parasitic upon flowering plants,

THE FUNGI WHICH CAUSE PLANT DISEASE 79

causing the ‘white rusts.’ The conidia are borne in white
blister-like sori under the raised and finally ruptured epidermis
of the host. The conidiophores are short, club-shaped, arranged

Fic. 50.—Albugo. A, section through a sorus showing epidermis, conidia,
conidiophores and mycelium; B, conidiophores and conidia; C, myce-
lium and haustoria. After Bergen and Davis.

in clusters; the spores are borne in basipetal succession and
remain attached in rather long chains unless disturbed.

The mycelium ‘is very fine, intercellular and penetrates the cells
by globular haustoria. The rudimentary odgonium is multi-
nucleate and filled with uniform proto-
plasm. As the odgonium grows older
the protoplasm within differentiates
into two parts, the inner part of dense
protoplasm, the odsphere, and the
outer part less dense, the periplasm.*!
Figs. 51, 53, 54. During this process
the nuclei enlarge, undergo one or two
mitoses, Fig. 54, and in some species
all the nuclei except one pass to the
periplasm. In other species the Fir A ite datheridial tube
odsphere is multinucleate at maturity. discharging sperms. After
The latter type is fertilized by nu- Stevens.
merous nuclei from the antheridium, the former by a single nu-
cleus.4!" 52. After fertilization the odsphere matures to an
odspore.

80 THE FUNGI WHICH CAUSE PLANT DISEASE

The globular odspores fall into two classes; * first tuber-
culate or ridged; second, reticulated. These are illustrated in
Fig. 52.

Fic. 52.—Oéspores of Albugo. 1. A. candida. 2. A. tropica. 3. A. ipomcee-
pandurane. 4. A.lepigoni. 5. A. swertie. 6. A. tragopogonis. 7. A. bliti. 8. A.
platensis. 9. A. occidentalis. 10. A. portulace. After Wilson.

The conidia in germination usually produce several ovate
zoéspores with two unequal, lateral cilia. After a brief period of
motility they became walled and produced germ tubes capable of
infecting susceptible hosts. The odspores after a period of rest

THE FUNGI WHICH CAUSE PLANT DISEASE 81

germinate in a similar manner. Conidia germinate freely only if
they are chilled.“

A. candida (Pers.) Roussel.*” Sori on all parts of the host except
the roots, white or rarely light-yellow, prominent and rather deep-
seated, variable in size and shape, often confluent and frequently
producing marked distortion of the host; conidiophores hyaline,
clavate, about 35-40 x 15-17 u; conidia, globular, hyaline, with
uniformly thin walls, 15-18 4; odspores, much less common than
conidia, usually confined to stems and fruits, chocolate-colored,

Fic. 54.—A. bliti,
showing differ- y
entiation of
oéplasm and Fia. 55.—A. bliti, an-

periplasm, the theridium showing

Fia. 53.—A. bliti, young oégo- nuclei in mito- the multinucleate

nium and antheridium show- sis. After tube. After Ste-
ing nuclei. After Stevens. Stevens. vens.

40-55 p; epispore thick, verrucose, or with low blunt ridges
which are often confluent and irregularly branched.

This is the most widely distributed and most common species
of the genus. It occurs throughout the world on a large number
of cruciferous hosts, and often gives rise to very pronounced
hypertrophy. Practically all cultivated crucifers, cabbage,
radish, turnip, etc., are subject to attacks of this fungus. In
Europe the caper and mignonette are attacked by the same
species. It has been reported in New York on Tropcolum.®

A. ipomoez-pandurane (Schw.) Sw.” }“ Sori amphigenous or
caulicolous, white or light yellow, prominent, superficial, 0.5—
20 mm., rounded, often confluent and frequently producing
marked distortions of the host; conidiophores hyaline, clavate,

82 THE FUNGI WHICH CAUSE PLANT DISEASE

unequally curved at base, 15 x 30 yu; conidia hyaline; short-
cylindric, all alike or the terminal more rounded, 14-20 x 12-18 uy;
the membrane with an equatorial thickening, usually very pro-
nounced. Oésporic sori separate from the conidial, caulicolous,
rarely on petioles, 1-2 x 5-6 cm. or even more, causing marked
distortion; odspores light yellowish-brown, 25-55 yu; epispore
papillate or with irregular, curved ridges.

Common throughout the world on various species of Convol-
vulacez, morning glory, moon flower, sweet potato, etc., although
causing but little damage.

A. occidentalis G. W. W., reported by Pammel ™ on the beet
has been collected but once.

A. portulacee (D. C.) Kze. on purslane *! and A. bliti (Biv.)
Kze.* occur on Amaranthus and related plants.

A. tragopogonis (D. C.) S. F. G.54 4 Sori hypophyllous or
caulicolous, prominent, deep-seated, white or yellowish, pul-
verulent, rounded or elongate, 1-3 x 1-8 mm; conidiophores
hyaline, clavate, about 12-15 x 40-50 y; conidia, 12-15 x 18-22 p;
light yellow or hyaline, short-cylindric, the terminal larger and
less angular than the others, membrane with an equatorial thick-
ening; odspores produced in stems and leaves, dark brown or
almost black at maturity, opaque, 44-68 un, epispore reticulate,
areola 2 4; wing bearing papillate tubercles at its angles.

A cosmopolitan species of less economic importance in America
than in Europe attacking a wide range of hosts of the Composit.
Salsify is the chief economic host.

Peronosporacez (p. 78)

The members of this family, producing the diseases commonly
known as the “downy mildews,” have been long known and much
studied. They contain many important plant pathogens. The
globular odspores are in general indistinguishable from those of
the Aibuginacee but the conidiophores are quite different from
those of that family, being aérial instead of subepidemal. In
most cases they are branching and tree-like, Fig. 63, but in a
few genera they are short. The odspore in such genera as have
been studied (Peronospora * Sclerospora *) is formed as in Albugo
resulting when mature in an uninucleate egg surrounded by a

THE FUNGI WHICH CAUSE PLANT DISEASE 83

periplasm bearing the degenerate supernumerary nuclei. Fer-
tilization is as in the Albugos that have an uninucleate
egg. ts 44 52 58

The family has suffered many revisions of classification and
much renaming of genera. Plasmopara and Peronospora are
especially rich in a masquerade of names.‘ °5”

Key to GENERA oF Peronosporacese

Conidiophores scorpioid-cymosely branched;
conidia germinating by zoéspores. .... 1. Phytophthora, p. 84.
Conidiophores simple, monopodially or
dichotomously branched.
Conidiophores simple or monopodially
branched; conidia germinating by
zoospores or by a plasma
Conidiophores simple or irregularly
branched...............00008: . 2. Kawakamia, p. 89.
Conidiophores regularly branched
Conidiophores with the main axis
indurate, the lateral branches
reduced and basidia-like...... 3. Basidiophora, p. 89.
Conidiophores with the main
axis not indurate, the lateral
branches developed normally.
Conidiophores fugacious, stout,
sparingly branched; odspore
permanently united to the
wall of the odgonium. ....... 4, Sclerospora, p. 89.
Conidiophores persistent, slender,
usually freely branched; 06-
spore free from the wall of
the odgonium
Branches of the conidiophore

apically obtuse........... 5. Plasmopara, p. 90.
Branches of the conidiophore
apically acute. .........., 6 Peronoplasmopara, p. 93.

Conidiophores dichotomously branched;
conidia germinating by a germ tube.
Conidiophores with subapical disk-like
enlargements from which the ul-

84 THE FUNGI WHICH CAUSE PLANT DISEASE

timate branchlets arise radially;

germ tube produced from the apex

of the conidia.................. 7. Bremia, p. 95.
Conidiophores without subapical en-

largements; conidia germinating

from the side. ...............-.. 8. Peronospora, p. 95.

Phytophthora de Bary (p. 83)

This genus is of especial interest on account of its one exceed-
ingly destructive representative, P. infestans, which occupies an
historic position in phytopathology as one of the earliest of para-
sitic fungi to receive study in any way complete or adequate;
study moreover which did much to turn attention and interest
toward plant pathology.

A distinctive character is that the conidiophores have irregular
thickenings below the apparently lateral conidia. The conidio-
phore is at first simple and bears a single apical conidium, after
the production of which a lateral branch arises below the conidium
and grows on in such a way as to give the first conidium a lateral
appearance. This process is, in some species, repeated until a
large scorpioid cyme is produced. The genus
contains seven or eight species, all parasitic.
The mycelium is much branched, non-septate,
hyaline; the conidiophores arise singly or in
groups from the stomata, or break through
the epidermis; conidia oval, papillate; zoé-
spores oval, biciliate, escaping by rupture of
the papilla; odspores, when present, with the
epispore more or less ridged.

P. phaseoli Thax.***!_ Mycelium well de-
veloped, intracellular; conidiophores single or
Seether ee : clusters from the stomata, simple or

tails of P. phaseoli. branched below, apparently simple above

After Thaxter. but really one to many times cymosely
branched; conidia oval or elliptic, papillate, 35-50 x 20-24 uy;
germination by about fifteen zodspores. Oédgonia in the seed
coats or cotyledons of seeds, rarely in the pods, thin walled,
slightly folded; subspherical 23-28 4; Odspores spherical or

85

THE FUNGI WHICH CAUSE PLANT DISEASE

“souo0r Jo V

*890}8}0d Jo satyalic

A OM} UO YYAOIZ JO soUaIayIp Furmoys ‘suvysojut

‘d— Lg “lg

86 : THE FUNGI WIiICH CAUSE PLANT DISEASE

subspherical with smooth, moderately thick walls, hyaline or
light yellow, 18-26 yu. It was described on lima beans in 1889.
The methods of infection were studied by Sturgis © who showed
that spores are carried to the basal portion of the style and ovary
by visiting insects. Odspores were described and extensive arti-
ficial culture experiments made by Clinton ® who first grew the
fungus successfully in pure culture on corn-meal-agar, and other
media, on which odspores were produced in abundance.

The species is unique within the genus on account of the single
conidia which are borne at the apex of apparently simple conidio-
phores but subtended by several enlargements of the kind so
characteristic of the genus.

P., infestans (Mont.) de Bary 54 14% 146-148

Mycelium well developed, probably perennial; conidiophores
single or in groups of 2-4 from the stomata; scorpiose-cymosely
branched; conidia 27-30 x 15-20 y, ovoid, germinating by about
six to sixteen zodspores. :

On diseased solanaceous.hosts, particularly the potato and
tomato,™ this species is very destructive. It was first described
in 1845 as a Botrytis and
has since been the subject
of many extensive papers.

The conidiophores are
abundant on the lower sides
of infected leaves near the
invasion line. The myce-
lium migrates between the
cells piercing them with
haustoria.

: The existence of odspores

Fia. a ee A ogamey ce ous of is a much _ controverted
point; the structures re-

ported by Smith ®*’ as odspores probably belonged to some other
fungus. Recently Jones® found peculiar thick-walled bodies,
somewhat resembling odspores, in undoubtedly pure cultures of
P. infestans. Whether they are odspores is not known. Clinton
bee recently announced ss that he, in pure cultures, has obtained
absolutely perfect odgonia, antheridia and even odspores.”” The

THE FUNGI WHICH CAUSE PLANT DISEASE 87

oval, flattened biciliate zodspores which emerge from the conidia,
swim about, come to rest, develop a wall, then produce a germ
tube. Direct germination by a germ tube also occurs rarely. In-

if

Fic. 59.—P. infestans; 1, section showing conidiophores and conidia-
formation; 5, germination of a conidia. After Scribner.
fection is brought about by the germ tube, either by penetrating
through stomata or directly through the epidermis.

The walls and contents of parasitized cells are browned. When
this fungus is alone on the tubers dry rot is induced, but invasion
of numerous saprophytic fungi and bacteria usually turns this
into a disagreeable wet rot. Tuber infection occurs largely from

88 THE FUNGI WHICH CAUSE PLANT DISEASE

conidia washed into the soil by rain; possibly sometimes by the
mycelium migrating by way of the stem.

The fungus was extensively studied by Jones in pure culture and
a decided difference in luxuriance of growth was observed on blocks
cut from different varieties of potatoes, Fig. 57.

The mode of hibernation is not thoroughly known but undoubt-
edly hibernation occurs in part in live mycelium in infected
tubers.” The conidia are short-lived, especially when dry.

P. omnivora de Bary. Conidiophores simple or branched;
conidia ovoid or lemon-shaped, 50-60 or even 90 x 35-40 x, ger-
minating by as many as fifty zodspores; odspores smoothish or
wrinkled, light-brown, transparent, 24-30 yu. This species which
includes forms previously described as P. cactorum (Lebert &
Cohn) Schr., P. fagi Hartig, and P. sempervivi Schenk is found
upon seedlings of some fifteen families ranging from Pinace to the
higher Angiosperms. It is of considerable economic importance
in Europe especially in the seed beds of the forester. Recently it
has been found on ginseng in
Japan and the United States.”!
The same fungus is credited with
destructive rotting of apples 7?
and pears”? in Europe and with
causing two wide-spread tropical
diseases, the cocoa pod rot and a
palm disease. From the studies
of de Bary ™ and from the nature
of the more recent outbreaks cred-
ited to this fungus it appears that
P. omnivora is a composite species
gE ner rire of gwarm-spore which will eventually be segre-

gated. Indeed segregation has

already been begun. Coleman” has described the palm in-

fecting fungus of India as P. omnivora var. arece while Maub-

lanc has gone further and described the cocoa disease as P.
faberi. See also ™ 7

P. syring# recently described by Klebahn is a closely related

species, which is very destructive in the propagating beds of the
lilac in Germany.

THE FUNGI WHICH CAUSE PLANT DISEASE 89

P. agaves Gan.” occurs on the Agave in Mexico.

P. nicotiana v. B. d H.® is also closely related to P. omnivora,
but culture work shows it to be rather fastidious in its choice of
host as it attacks only tobacco seedlings.

P. calocasiz Rac. occurs on Calocasia antiquorum in the Orient.
An undescribed species on Castor is also reported.®!

Kawakamia Miyabi (p. 83)

Mycelium slender, copiously branched; conidiophores single or
in groups of 2-5 or more from the stomata, simple or sometimes
irregularly branched, but branches never arising near the conidia.
Conidia usually upon a slender pedicel cell, lemon-shaped, ob-
tusely tipped, contents and wall colorless, germination normally
by zodspores; zodspores oval, flattened and laterally biciliate;
odspores spherical, smooth.

A single species, K. cyperi (M. & I.) Miyabe,®* which was intro-
duced from Japan into Texas in imported plants of a sedge,
Cyperus tegetiformis. The species is very destructive in Japan.
Both conidia and odspores were produced in the Texan material.®?

Basidiophora Roze & Cornu (p. 83)

B. entospora R. & C. occurs on species of Erigeron and culti-
vated aster in Europe and America.

Sclerospora Schriter (p. 83)

This genus differs from all other Peronosporales in the pre-
ponderance of its odspores; these are the conspicuous stage, while
the conidiophores and conidia are few, small and evanescent.
There are about five species.

Mycelium much branched, with small vesicular haustoria;
conidiophores erect, solitary or in groups of two or three,
fugaceous, low and stocky, sparsely branched, the branches
also stocky; conidia elliptic or globose-elliptic, hyaline, smooth;
odspores globose, intramycelial, the epispore brown, irregularly
wrinkled, permanently united to the persistent wall of the odgo-
nium.

90 THE FUNGI WHICH CAUSE PLANT DISEASE

S. graminicola (Sacc.) Schr.,°* °? infects leaves and inflorescences,
the odspores causing marked distortion of the latter and rapid
disintegration of the former; conidiophores 100 x 10-12 yu, conidia
20 x 15-18 yw; odgonium wall thick, 4-12 y, at maturity 30-60 yu
in diameter, reddish-brown; odspore pale-brown, 26-36 u.

The conidial phase is not prominent, while the odspores by their
disintegrating effect upon the leaves of the host, render the plants
quite conspicuous and closely simulate the habit of a brown smut.

©, S

Fia. 61.—S. graminicola.

Conidiophores and co- Fic. 62.—S. graminicola, 06-
nidia; germinating gonium, odspore and an-
conidia and z06- theridium in section. Af-
spores. After Butler. ter Stevens.

On millet (Setaria italica), pearl millet, fox tail and corn; in India
of considerable economic importance.**

S. macrospora Sacc. has been reported in corn tassels and on
wheat in Italy and the United States.8* 8° (Conidia unknown;
odgonia embedded firmly in the tissue of the host, not causing
disintegration as in 8. graminicola; odspores light yellow, smooth,
60-65 py.

Plasmopara. Schroter (p. 83) 134

The tree-like, branching conidiophores, Fig. 63, are common to
this genus, Peronospora, Peronoplasmopara and Bremia, and
unlike the conidiophores of Phytophthora they are completely
formed before they begin to bear spores.

Mycelium branched; haustoria simple; conidiophores erect,

THE FUNGI WHICH CAUSE PLANT DISEASE 91

solitary or fasciculate, from the stomata of the host, monopodi-
ally branched, the branches arising at right angles to the main
axis, as do also the secondary branches (at least never appearing
truly dichotomous) the ultimate branches apically obtuse; conidia
glebose to ovoid, hyaline or smoky, germinating by zodspores or
the entire protoplasmic mass escaping and then sending out a
germ tube; odspore globose yellowish-brown, the epispore va-
riously wrinkled sometimes appearing somewhat reticulate; odgo-
nium persistent, but free from the odspore.

P, viticola (B. & C.) B. & d T.,™ * ™ 4 1 first collected in
1834 by Schweinitz and regarded as a Botrytis was first published
in 1851.8

Hypophyllous, caulicolous, or on young fruits, covering the
infected areas with a white downy growth; on the leaves epiphyl-
lous discoloration yellowish; on the fruit often causing a brown rot
without producing conidia; conidiophores fasciculate, 250-850 x
5-8 uw, 4-5 times branched, the ultimate branchlets about 8 u long;
conidia ovate-elliptic, very variable in size, 9-12 x 12-30 u;
odspores 30-35 yu, epispore brown, wrinkled, or almost smooth;
odgonium thin-walled, hyaline or light yellowish-brown.

The mycelium is found in all diseased tissues except the xylem.
The conidiophores issue from stomata. The conidia germinate
readily in water, producing in about three-fourths of an hour
biciliate zodspores. These after fifteen to twenty minutes activity
cease motion, round off, become walled, then germinate by a tube.
This bores through the epidermis and develops into the internal
mycelium. Infection is almost exclusively from the lower side of
the leaf.2* Odspores are much more rare than conidia but are often
found in autumn, sometimes two hundred to a square millimeter of
leaf surface. Though hibernation is doubtless chiefly by odspores
it has been shown that the mycelium can perennate in old wood,
and even form odspores therein. The fungus is dependent on
abundant moisture.

P. nivea (Ung.) Schr. attacks various species of umbellifers in-
cluding the parsnip and carrot. It has been reported in America
only from the region of San Francisco.

P. halstedii (Farl.) B. & d T.

‘This form is quite variable and should perhaps be separated

92 THE FUNGI WHICH CAUSE PLANT DISEASE

into several distinct species. It is limited to the Composite,
Helianthus and Madia being the only hosts of economic impor-
tance.

Hypophyllous; conidiophores fasciculate, slender, 300-750 un,
3-5 times branched, ultimate branchlets 8-15 » long, verticillate

Fia. 63.—P. viticola. .A, section of a leaf with conidiophores emerg-
ing from a stoma; C, formation of swarm spores; D, formation
of oéspores. After Millardet.

below the apex of the branching axis which is frequently swollen

and ganglion-like; conidia oval or elliptic, 18-30 x 14-25 uy;

odspores 30-32 yu, epispore yellowish-brown, somewhat wrinkled.
P. ribicola (Schr.) Schr. grows on various species of currants in

Europe and America but is probably of but slight economic
importance.

THE FUNGI WHICH CAUSE PLANT DISEASE 93

P. obducens (Schr.) Schr. occurs on Impatiens, both wild and
cultivated, in North America, Europe and Asia.

P. pygmea (Ung.) Schr. on various Ranunculaceex, including
Aconitum in Europe and cultivated Hepaticas in America,” is
of little economic importance.

Peronoplasmopara (Berlese) Clinton (p. 83)

There are three species which have been variously designated
as Peronospora, Plasmopara, Pseudoplasmopara and Peronoplas-
mopara. The genus combines colored conidia and zodsporic germi-
nation with a type of conidiophores intermediate between those of
Peronospora and Plasmopara.

Mycelium much branched, haustoria small, usually simple;
conidiophores pseudo-monopodially branched, the ultimate branch-
lets acute, the primary arising at acute angles; conidia colored,
elliptic, conspicuously papillate both apically and basally; oéspores
thin-walled, smooth or roughened; odgonium thin-walled.

P. celtidis (Waite) Cl.*! is unique in the family as the only
species infecting dicotyledonous trees. It occurs on hackberry in
the region about Chesapeake Bay, also in Japan.

P, humuli Miy. & Taka *? causes a serious hop disease in Japan.
It has recently been found by Davis * on wild hops in Wisconsin.

P. cubensis (B. & C.), Cl.94% 102

Hypophyllous, rarely amphigenous; discoloration of the host
yellowish, or water-soaked; conidiophores 1-2 rarely more from a
stoma, 180-400 x 5-9 u, 3-4, rarely 2-5 times branched, the ulti-
mate branchlets recurved; apically acute, 5-20 yu long; conidia
gray, brownish or smoky, ovoid to ellipsoid, papillate, 20-40 x
14-25 y; odspores spherical, yellowish, warty-papillate, 30-43 u,
maturing in the decaying leaves.

The mycelium abounds in the spongy parenchyma. The
conidiophores emerge through stomata, or rarely directly through
the cuticle, near the invasion line of the fungus. Fresh conidia
germinate in water in two to four hours forming flattish zodspores
with one anterior and one posterior cilium. The zodspores later
become spherical, walled and develop a germ tube. These germ
tubes enter the host through the stomata or directly through the
cuticle from either above or below. Moist weather is favorable to

94 THE FUNGI WHICH CAUSE PLANT DISEASE

the fungus in that conidia are produced more abundantly and
retain their power of germination longer when moist. Disease
spots appear two or three days after infection; conidia same nine
or ten days after infection.

The species is perennial in Florida and spreads northward as
the season advances, reaching Ohio and New York by late summer

Fic. 64.—P. cubensis: 3. Conidiophore with young and
old conidia. 5. Conidium. 6. Conidium germinating.
11. Zodspores. 18. Infection through a stoma.

After Clinton.
or early autumn.” For a series of years after its discovery it was
not well known even scientifically, its first serious outbreak being
about 1889.” It appeared in Japan about the same time ™ and
is now known to be almost cosmopolitan. The odspores have
been found only by Rostewzew and have not been seen in America.
A wide range of wild and cultivated cucurbits is infected, among

THE FUNGI WHICH CAUSE PLANT DISEASE 95

them the pumpkin, squash, cucumber, muskmelon, watermelon,
gourd, in fact according to the work of Selby any cucurbit ap-
pears liable to attack. Clinton infected muskmelons with spores
produced on cucumber. The fungus is especially prevalent on
cucumbers raised under glass.

Bremia Regel (p. 84)

As in Peronospora except that just below the ends of the conidio-
phore branches there are pronounced swellings from which spring
radially a number of short branches each
bearing an ovate, papillate conidium. The
conidia germinate by apical germ tubes.

There is only one species.

B. lactuce Regel is found on lettuce and 0
several other Composite. It is more in-
jurious in Europe than in America.

Hypophyllous or amphigenous, causing

discoloration, then wilting of the host; conid- iq. 65.—B. lactuce.
iophores produced singly but in great abun- After Tubeuf.
dance, much branched; conidia ovate, 16-22 x 15-20 mu; odspores
small, 26-35 y, light brown, the epispore wrinkled.

Peronospora Corda (p. 84) *?

This genus of some sixty species contains several aggressive
parasites. Its conidiophores are much like those of Plasmospara
but with more tendency to dichotomous branching and to more
graceful habit; the apices are acute.

Mycelium well developed, haustoria filiform, simple or
branched; conidiophores dichotomously 2-10 times branched at
acute angles, ultimate branchlets acute, more or less reflexed;
conidia hyaline or colored, papillate, germinating directly by lateral
germ tubes; ospores globose, reticulate, tuberculate, wrinkled or
smooth.

P. parasitica (Pers.) De Bary.“ This is often associated with
Albugo candida, giving it the appearance of a parasite on that
fungus. Almost all species of Crucifere are subject to attack,
among them cabbage, cauliflower, radish, collards, turnips, horse-

96 THE FUNGI WHICH CAUSE PLANT DISEASE

radish, and others of minor economic importance. It is cos-
mopolitan in distribution. ;

The fungus covers any green part of the host with a dense white
growth, often causing hypertrophy especially in odspore forma-
tion; conidiophores 200-300 x 10-12 u, bushy branched, stout,
deliquescent, with 5-8 main branches, each from 3-7 times
branched, ultimate branchlets slender, more or less curved,
usually arising at acute angles, about 12-15 x 2-3 u; conidia
broadly elliptic, bluntish, often becoming globose, about 12-22 x
24-27 y, hyaline or very light; odspore
globose, yellow-brown, 26-45 y, epispore
smooth or wrinkled; odgonium thick, color-
less.

P. effusa (Grev.) Rab. causes a serious
disease of spinach. It also occurs on a
wide range of weeds of the Chenopodiacez.
The species was formerly made to include
all the effusee forms of the genus so that
literature abounds with references to it on
Viola, Plantago, Polygonum, etc.

Hypophyllous, causing yellowish or brown-
ish discolorations, the mass of conidiophores
of a violet cast; conidiophores 150-400 x
7-9 p, much branched, the ultimate branches
at right angles, usually recurved, 8-15 x
3-4 yu; conidia ellipsoid to globose 17-18 x
22-24 yp, violet or smoky; odspores globose,
. is : 30-40 yu, epispore light brown, more or
Sak * after ast less regularly wrinkled; odgonium thin,
ssi brown.

P. schleideni Ung.’ was first, described as a Botrytis in 1841.
It was noted in America in 1872 by Taylor, later by Trelease
and by many others. A very complete description was given
by Whetzel ! in 1904 under the name P. schleideniana.

The conidia in mass present a purplish tint. The- conidio-
phores usually emerge singly through the stomata.. The slender,
branched haustoria abound in the parasitized part often with
their ends wrapped around the nuclei. In water the conidia

THE FUNGI WHICH CAUSE PLANT DISEASE 97

germinate directly to form an infective tube (Fig. 67) which
grows into the stomata. According to Whetzel gonidia retain
their germinating power only a few hours. Shipley believed them
viable for a much longer time. Fertilization occurs much as in
P. parasitica (Fig. 67) and the sexual spores, which abound,
serve for hibernation. They may live several years.

It is found on onion, garlic, etc. (Allium sps.) everywhere,
covering leaves with a dense growth; conidiophores, 3-6 times
branched, 300-700 x 12-15 y; branches 2-5, scattered, ultimate
branchlets subulate, 15-20 u, more or less recurved; conidia large,
obovate to pyriform, basally papillate, 45-58 x 20-25 u, the
membrane violet; odspore globose, light-brown, about 30 u,
epispore smooth or slightly wrinkled.

P. sparsa Berk. is parasitic on roses *” and constitutes a serious
pest in Europe, though not so common in America.

Hypophyllous, with a whitish growth; conidiophores about
9 times branched, the ultimate branchlets reflexed; conidia sub-
elliptic, pale gray.

P. trifoliorum de Bary. Hypophyllous, forming a dense grayish
or dirty-white growth over the host; conidiophores slender, 360—
600 x 9-11 y», 6-8 times branched at acute angles, the primary
branches rather erect, the secondary more spreading, flexuose, more
or less recurved, ultimate branchlets at right or obtuse angles,
straight, subulate, 7-12 x 7-3 u; conidia globose to broadly elliptic,
15-20 x 18-36 yu, violet; odspores globose, 24-30 yu, epispore light
brown, smooth.

It causes serious loss to clover in Europe. Species of related
genera also suffer. Recently it has assumed a réle of importance
in America by its attacks upon Alfalfa 1° on which it occurs from
New York to California.

It differs from P. vicie in the branching of the conidiophores,
the lighter color of the spot and fungus, and the smooth odspores.

P. vicie Berk. Hypophyllous or caulicolous, covering the host
with a grayish-violet growth, epiphyllous discolorations yellowish
or inconspicuous; conidiophores fasciculate, 300-700 x 9-11 un,
5-8 times branched, the main branches arising at acute angles,
erect, the ultimate subequal, slightly flexuose, arising at right or
obtuse angles, the lateral recurved, 10-17 x 2-3 y; conidia elliptic

98 THE FUNGI WHICH CAUSE PLANT DISEASE

Fia. 67.—P. schleideni. 11. Mycelial threads between the large conductive cells of
the leaf; (a) the mycelial thread; (b, b) branched or coiled haustoria; (c) branched
haustorium wrapped about the nucleus. 13. Young conidiophores, ( a) turn-
ing toward the stoma, (b); (c) haustorium wrapped about the nucleus of the
epidermal cell. 14. Mature conidiophore (a) with mature conidia, (c, c);
(d) germ tube of conidium entering stoma. 15. Odspores, (a) mature odspore
with old antheridium, (d) still attached; (b) mature odspore still inclosed in the
old wall of the oédgonium. After Whetzel.

THE FUNGI WHICH CAUSE PLANT DISEASE 99

or obovoid, 15-20 x 21-28 uy, light-violet ; Odspores small, 25-30 yu,
epispore yellowish-brown, with low, broad reticulations, areole
about 8 »; odgonium thin, fugaceous, 32-40 p.

This fungus on Vicia and related genera is sometimes quite

Fic. 68.—A sporangium with a columella (Mucor).
After Sachs.
serious, particularly on vetch and peas in Europe, Asia and
America.

P. viol de Bary; on cultivated violets and the pansy in Europe
and America,*’ forming discolored spots; foliicolous or caulicolous,
with a pale violet growth, conidiophores fasciculate, short, 2-7
times dichotomously branched; ultimate branchlets short, sub-
ulate, reflexed; conidia elliptic, short, apiculate, 20-22 x 15-18 uy,
violet.

100 THE FUNGI WHICH CAUSE PLANT DISEASE

P. dipsaci Tul. on teasel and Scabiosa in Europe and America and
P. violacea Berk. on the flowers of species of Scabiosa in Europe
are quite distinct from the preceding; P. schachtii Fcl. on beets
kills seedlings in Europe. P. linariz Fel. is on digitalis; P. cytisi

Fria. 69.—Sporophores in the Zygomycetes. After De Bary,
Brefeld, Cunningham, Schréter.

Rost." 1!? on species of Cytisus in Europe; P. arborescens (Berk.)
de Bary on poppies, especially garden seedlings, in Europe and
Asia.

Species of less importance are:

P. rubi Rab. on various species of Rubus in Europe and
America; P. fragarie R. & C., usually cited as a synonym of
P. potentille de Bary, on the strawberry in France and America;
P. trichomata Mas.!!* 114 the cause of a root rot of Colocasia

THE FUNGI WHICH CAUSE PLANT DISEASE 101

in the West Indies; P. candida Fcl. on the primrose in Europe
and upon non-economic Primulacez in America; P. maydis Rac.1!°
the cause of a disease of corn in Java. [Its identity with Sclero-
spora graminicola is suggested by the recent studies of that species
by Butler.] P. vince Schr. on Vinca minor in Europe; P. myoso-
tidis de Bary on several species
of forget-me-not and related
genera in Europe and America;
P. cannabina Otth. on hemp in
Europe and Japan; P. con-
glomerata Fel. upon alfilaria
in Europe; P. ficarie Tul. on
various species of Ranunculus
both in the old and the new
world; P. antirrhini Schr. on
the snapdragon and related
hosts in Europe; P. nicotiane
Speg." on various ornamental
species of Nicotiana in South Fie. 70.—Mucor: zygospore formation.
America and California; P. va- Biter Becteld

leria melle Fcl. in Europe on Valerianella; P. valeriane Trail on
Valerian; P. dianthi de Bary on species of Dianthus in Europe;
P. coralle Tranz. on Campanula in Europe; P. jaapiana ” on
rhubarb in Europe; P. phcenixee Tap. on Phcenix 1 and an un-
determined species on Para rubber.

Mycelophagus castanee Man.’” is an imperfectly described
form which may belong either to the present group or to the
Chytridiales. A serious disease of the chestnut in France is
charged to it.

Zygomycetes (p. 66)

This group of fungi is readily distinguished from the Odmycetes
by its isogamous sexual organs, when these are present. In the
absence of sexual organs the general type of sporangium is usually
sufficient mark of distinction for those who are even but slightly
acquainted with the two groups. The mycelium, if young, serves
to indicate relationship to the Phycomycetes. Older mycelium is
often septate and would lead the unwary into errors of classification.

102 THE FUNGI WHICH CAUSE PLANT DISEASE

Asexual spores are either in sporangia or are borne as conidia.
The sporangium is usually with a columella. The spore-bearing
stalks exhibit the widest diversity in shape and form of branch-
ing, Fig. 69.

Sexual spores (zygotes) are produced through the union of two
like gametangia. (Fig. 70.) Though the cytology of zygote
formation has not been completely studied it seems clear that the
fertilization is multi-nucleate }*° as in Albugo bliti and that the
two uniting elements are ccenogametes.

Key To Orpers or Zygomycetes

Asexual spores borne in sporangia which
in some genera are reduced to

conidia-like bodies...............- 1. Mucorales, p. 102.
Asexual spores true conidia borne singly
at the apex of the conidiophores.... 2. Entomophthorales, p. 107.

Mucorales (p. 66)

This order is comprised mainly of saprophytes, about twenty
genera and one hundred fifty species; but includes a few forms
which prey upon vegetation in a very
low ebb of life, as cells of ripe fruit,
tubers, etc., and a few species which
are of especial interest as they grow
upon other fungi. The sporangial
stage is exceedingly common; the
zygosporic much less so, very rare in
the case of some species. Blakeslee !2°
has shown that in some species,
though the two uniting sexual organs
Se poms are to all appearances alike, the plants

contact between + and — are in reality dicecious; that a branch

strains. After Blakeslee.
from one plant cannot produce sexual
organs that will unite with other sexual organs produced upon
the same plant. Moreover, there appears to be a differentia-
tion of sex in that one plant, which may provisionally be re-

THE FUNGI WHICH CAUSE PLANT DISEASE 103

garded as the male, unites freely with another plant, provisionally
the female, but this male plant refuses to unite with any other
plant which is capable of uniting with the female and all plants
that can unite with the male refuse to unite with the females. In
some species the plants of one sex show a more luxuriant vegeta-
tive growth than do plants of the other sex.

Key To Famiuies oF Mucorales.

Asexual spores in typical sporangia, although
in some genera few-spored
Sporangium with columella; zygospores
naked or thinly covered with out-
growths of the suspensor........... 1. Mucoracea, p. 103.
Sporangium without a columella; zygo-
spores closely covered by hyphe. .. 2. Mortierellacez.
Asexual sporangia monosporic and conidia-
like, sometimes accompanied by larger
polysporic sporangia
Sporangia of two kinds, polysporic and

MOMNOSPOTIC.... 2.2... 3. Choanephoracea, p. 106.
Sporangia all monosporic; parasitic on
other genera of Mucorales......... 4. Chetocladiacer.

Sporangia simulating chains of conidia.. 5. Piptocephalidacex.

Of these families the second and fifth are pure saprophytes,
while the fourth is parasitic upon other members of the order.

Mucoracez

Mycelial threads all alike or of two kinds, one aérial, the other
buried in the substratum, ccenocytic during growth but septate
at maturity; reproduction by asexual spores borne in sporangia
and by zygospores formed by the union of equal gametes; spor-
angiophores, simple or branched; sporangia variable, typically
with a columella, and many spores but in some genera some of
the sporangia are few-spored and without columellas; zygospores
variable, smooth or spiny, borne on short branches of the myce-
lium.

104 THE FUNGI WHICH CAUSE PLANT DISEASE

Key to SUBFAMILIES AND GENERA OF Mucoracee

Sporangial membrane cuticularized and per-
manent above, thin and fugaceous be-

loWisenk cats ek ee Subfamily I. Pilobolez.
Sporangiophore of equal size throughout;
spore mass not forcibly discharged... Pilaira.

Sporangiophore swollen beneath the spo-
rangium; spore mass forcibly dis-

charged at maturity............... Pilobolus, p. 105.
Sporangial membrane thin and fugaceous
throughout
Sporangia all similar...... Subfamily II. Mucoree.

Mycelium differentiated into a colorless
vegetative and a colored aérial re-
gion

Aérial mycelium stoloniferous, zygo-
spores formed in the substratum
Sporangiophores arising from the

TOMES 4.6 Gear eon Se ase 1. Rhizopus, p. 105.
Sporangiophores arising from the
internodes... ................ 2. Absidia.

Aérial mycelium not stoloniferous;
zygospores aérial

Sporangiophores simple .......... 3. Spinellus.
Sporangiophores dichotomously
branched... ................. 4. Syzygites.

Mycelium undifferentiated
Mycelium gray or brown; suspensors
smooth
Sporangiophores simple .......... 5. Mucor, p. 106.
Sporangiophores variously branched
Sporangia borne apically on the
sporangiophore and __ its

branches
Zygospores formed from equal
gametes... .............. 6. Calyptromyces.
Zygospores formed from un-
equal gametes........... 7. Zygorhynchus.

Sporangia borne only on the
lateral, circinate branches of ,
the sporangiophore

THE FUNGI WHICH CAUSE PLANT DISEASE 105

Sporangia globular; columella

not constricted. ......... 8. Circinella.
Sporangia pear-shaped; colu-
mella constricted........ 9. Pirella.

Mycelium metallic; suspensors spiny 10. Phycomyces.
Sporangia of two kinds, the primary

many-spored; the secondary few-

spored ................ Subfamily III. Thamnidiex.

Pilobolus crystallinus (Wigg.) Tode, a form with beautiful
crystalline sporangia on yellowish, evanescent sporangiophores has
been frequently noted as injuring or smudging chrysanthemum,
rose and other leaves ?!?"}°? by its profuse discharge of spo-
rangia. It is not, however, a parasite.

Of the other genera the only ones of interest regarding: plant
disease are Rhizopus and Mucor. The others are saprophytes found
on a great variety of substances, manure, fungi, and many other
kinds of organic matter.

Rhizopus Ehrenberg (p. 104)

The sporangium wall is not cutinized, and falls away. The
sporangia are all of one kind and with columellas. The sporan-
giophore is never dichoto-
mous; zygotes are found in the
mycelium. The suspensor is
without outgrowths. Twelve
or fifteen species, chiefly sap-
rophytes.

R. nigricans Ehr. Aérial
mycelium at maturity choco- Fic. 72.—Rhizopus. Diagram showing
late-colored; rhizoids numer- mycelium and sporophores. After Coul-

ter, Barnes and Cowles.

ous; sporangiophores fascicu-

late, erect, aseptate; sporangia globose, blackish-olive, granular;
columella hemispheric; spores gray to brown, subglobose or irregu-
lar, 11-14 yw; zygospore 150-200 yu, epispore with rounded warts,
black. This is the cause of soft rot of stored vegetables, particu-
larly of sweet, potatoes,!” also of Irish potatoes,’ apples and pears;
it causes death of squash blossoms }” and is destructive to barley

106 THE FUNGI WHICH CAUSE PLANT DISEASE

during malting. It is distinctly a wound parasite and is unable
to force entrance through a sound epidermis.

The richly branched mycelium which varies from very thin and
hyaline to thick, coarse and slightly fuscous, is found throughout
the rotten portion of the host. After a period of luxuriant vegeta-
tive growth hyphe protrude to the air, first through existing
ruptures in the epidermis, later by rifts forced by the fungus
itself. Sporangiophores then form in dense bush-like growths,
each sporangiophore bearing one terminal sporangium. The
sporangia are at first white, later black and contain very numerous
spores. Spore formation has been closely studied by Swingle.”
Aérial stolon-like hyphz reach out in various directions and at
their points of contact with some solid develop holdfasts (Fig. 72)
and a new cluster of sporangiophores.

Zygotes are produced by union of two mycelial tips as is shown
in Fig. 70.

Orton '** inoculated pure cultures of this fungus on sterile raw
Irish potato and induced typical decay. He also noted that there
was a difference in the rate of decay produced by strains of Rhizo-
pus derived from different sources and that thé most rapid decay
of potatoes was caused by strains taken from rotting potatoes.

R. necans Mas.'”’ causes decay of lily bulbs in Japan.

R. schizans Mas. is cited as the cause of split-stone in peach.!

Mucor Linnzus (p. 104)

Mycelium all of one kind, buried in the substratum or grow-
ing over its surface; sporangiophores scattered or not, simple
or branched; sporangia globose; columella cylindric, pyriform or
clavate; spores numerous, variable; zygospores globose, smooth or
warty.

Some thirty species, chiefly saprophytes.

M. mucedo L. is destructive to beech nuts in winter.

; M. pyriformis Fisch and M. racemosus Fes. cause decay of
ruits.

Choanephoracee (p. 103)

Mycelium parasitic on living plants; sporangia of two kinds;
macrosporangia globose, columella small, spiny, spores few, on

THE FUNGI WHICH CAUSE PLANT DISEASE 107

simple or branched, erect sporangiophores; microsporangia clavate,
one-spored simulating conidia and borne in heads on the enlarged
apices of umbellately branched sporangiophores; zygospores as
in Mucorace.

A single genus, with three species.

Choanephora infundibulifera (Curry) Sacc. and C. americana
A. Moll occur on blossoms in India and South America.

A third species, C. cucurbitarum (B. & Br.) Thaxter, is the
cause of decay of cucurbits especially pumpkins, in the eastern
and southern states.

Entomophthorales (p. 66)

This order is predominately one parasitic on insects. Some
fifty species are known, only four of which are plant parasites.
Asexual reproduction is chiefly by conidia, apically borne and for
the most part forcibly ejected from their stalks at maturity.

Key To Fami.ies or Entomophthorales

Endozoic parasites (Insecta, Arachnoidea). 1. Entomophthoracee.
Endophytic or saprophytic. .............. 2. Basidiobolacee, p. 107.

Basidiobolaceze

This family is characterized chiefly by its habitat. Septa are
numerous in the vegetative mycelium.

Key to GENERA OF Basidiobolacee

Intracellular parasites, the mycelium greatly
TOCUCED 5s os So es ees Be PS 1. Completoria, p. 108.
Saprophytes, or parasites on higher fungi,
the mycelium well developed.
Conidia produced directly from an un-
swollen conidiophore. Parasites on
higher fungi. ..... .......-.------ 2. Conidiobolus.
Conidia cut off from the apex of a swelling
of the conidiophore. Saprophytic... 3. Basidiobolus.

108 THE FUNGI WHICH CAUSE PLANT DISEASE

With the exception of the one spccies given below these are not
parasitic on higher plants.

Completoria complens Lohde is parasitic upon fern prothallia.1

Vegetative body compact, of oval or curved branches in a single
host cell, extending to other cells by slender tubes. Resting spores
10 to 20, formed in the host cell. Propagation by non-motile
conidia, 15-25 y, in diameter.

BIBLIOGRAPHY OF PHYCOMYCETES *
(pp. 59-108)

1 Atkinson, G. F., Ann. Mye. 7: 441, 1909.
2 Stevens, F. L. and Hall, J. G., Bot. Gaz. 48: 1, 1909.
3 Bessey, Ernst, Diss, Halle, 1904.
‘Smith, E. F., B. P. I. B. 17: 13, 1899.
5 Milburn, Thomas, C. Bak. 13: 129, 257, 1904.
6 Woronin, Jahrb. Wiss. Bot. 11: 556, 1878.
7 Horne, A., Ann. Myc. 7: 286.
8 de Wildeman, E., Mem. Roy. Belg. Soc. Mier. 21, 1893.
9 Stevens, F. L., Bot. Gaz. 35: 405, 1903.
10 Stevens, F. L., Ann. Myc. 5: 480, 1907.
11 Griggs, R. F., Bot. Gaz. 48: 339, 1909.
12 Kusano, C. Bact. 19: 558, 1907.
13 Percival, C. Bak. 25: 440, 1910.
14 Schilberszky, Ber. Deut. Bot. Gez. 14: 36, 1896.
16 Zimmermann, E., Nat. Zeit f. Forst u. Land. 8: 320, 1910.
16 Salmon, E. S. & Crompton, T. E., Wye Ag. Coll. R. Ec. Myc. 109,
1908.
17 Thomas, Insect Life 1: 279, 1884.
18 Halsted, B. D., N. J. B. 64: 4, 1889.
19 Shear, C. L., B. P. I. 110: 37, 1907.
20 Farlow, W. G., Bull. Bussey Inst. 2: 233, also Bot. Gaz. 10: 239, 1885.
21 Nowakowski Beitrag. Kennt, Chytrid. 1876.
22 Berlese, A. N., Riv. Path. Veg. 7: 167, 1901.
23 C, R. 119: 572, 1894.
4 C. R. 120: 222, 1894.
25 Ellis and Bartholmew, Trans. Kan. Acad. Sci. 16: 167, 1899.
2 B. My. d. Fr. 26:
7 C. R. 119: 108, 1894.
2 Magnus P. Ann. Bot. 11: 92, 1897.
29 Massee, Bull. Kew Garden, 1906.
30 Magnus, P. Ber. Deutsch. Bot. Ges. 20: 291, 1902.
31 Sydow. Ann. Myc. 1: 517, 1904.
32 Farlow, W. G., Rhodora 10: 9, 1908.
*See footnote, page 53.
109

110 THE FUNGI WHICH CAUSE PLANT DISEASE

33 Atkinson, G. F., N. Y. (Cornell) B. 94, 1895.

34 Mass. Agr. Exp. Sta. R. 8: 220, 1890.

35 Miyaki, Ann. Bot. 15: 653, 1901.

36 Butler, E. J., Mem. Dept. Agric. India, Botan. Ser. 14: 86-91, 1907.
37 Halsted, B. D., N. J. R. 18.

38 Butler, E. J., R. Pusa. 10: 44, 1909.

99 Smith, E. H. & Smith, R. E., Bot. Gaz. 42: 215, 1909.
4 Smith, R. E., Cal. B. 190.

41 Stevens, F. L., Bot. Gaz. 32: 77, 1901.

42 Stevens, F. L., Bot. Gaz. 28: 149, 1899.

43 Davis, B. M., Bot. Gaz. 29: 297, 1900.

44 Wager, H., Ann. Bot. 10: 295, 1896.

45 Wilson, G. W., Torr. Bull. 34: 61, 1907.

46 Melhus, I. E., Se. 33: 156, 1911.

47 Halsted, B. D., N. J. R. 11: 350, 1890.

4 Stewart, F. C., N. Y. (Geneva) B. 328, 1910.

49 Halsted, B. D., N. J. B. 76: 1890.

60 Pammell, L. H., Ia. B. 15: 236, 1891.

51 Halsted, B. D., N. J. R. 15: 355, 1894.

52 Ruhland, Diss., 1903.

53 Stevens, I’. L., Bot. Gaz. 34: 420, 1902.

54 Wilson, G. W., Torr. Bull. 34: 387, 1907.

55 J, Myc. 13: 205, 1907.

58 Clinton, G. P., Ct. R. 329, 1904.

57. Berlese, A. N., Riv. d. Pat. Veg. 9: 1, 1900; 10: 185, 1902.
58 Thaxter, R., Bot. Gaz. 14: 273, 1889.

59 Thaxter, R., Ct. R. (State) Sta. 167, 1899, 1890.

® Scribner, F. L., D. Agr. R. 337, 1888.

61 Lodeman, E. G., N. Y. (Cornell) Bul. 113: 249, 1896.
62 Sturgis, Bot. Gaz. 25: 191, 1898.

83 Clinton, G. P., Ct. R. 278, 1905.

64 Smith, R. E., Cal. B. 175, 1906.

65 Smith, W. G., Gard. Chron. 1875.

6 Smith, W. G., Quar. Jour. Mic. Sc. 15: 1875.

% Smith, W. G., Diseases of Crops, 1884.

* Jones, L. R., Sc. 29: 271, 1909.

* Clinton, G. P., Se. 33: 746, 1911.

7 Clinton, G. P., Ct. R. 362, 1904; also R. 304, 1905.
71 Whetzel, H. H., Sc. 31: 790, 1910.

7 Osterwalde, A., C. Bak. 15: 434, 1906.

73 Bubak, Fr., Zeit. 20: 257, 1910.

BIBLIOGRAPHY OF PHYCOMYCETES 111

74 de Bary, A., Bot. Zeit. 587, 1881.

78 Coleman, L. C., Mycol. Bull. 2: Dept. Agric. Mysore State, 1910.

% Maublanc, L’Agr. Prat. d. Pays Chauds 79: 315, 1909.

7 Ridley, H. N., Agr. B. Straits & Fed. Maley Sts. 10: 70, 1911.

78 Petch, T., Cire. and Agr. J. Roy. Bot. Gard. Ceylon 5: 143, 1910.

” Gandary, G., Mem. Y. Rev. Soc. Cient “Antonio Alzate” 25: 293,
1909.

80 Meded, Lands. Plant. Batavia 15: 1896.

*1 Butler, E. J., Rept. Agr. Research Inst. Pusa 10: 45, 1909-1910.

82 Patterson, F. and Charles V. K., B. P. I. 171: 1910.-

83 Kawakamia, a new genus belonging to Peronosporacee on Cyperus
tegetiformis. With a postscript by Dr. Kingo Miyabe, 1904.

84 Butler, E. J., Mem. Dept. Agric. India, 2: No. 1, 1907..

85 Cugini, G. and Traverso, G. B., Staz. sperim. Agr. Ital. 35: 46, 1903.

% Peglion, C. Bak. 28: 580, 1910.

87 Berkeley, J., Hort. Soc. Lond. 6: 289, 1851.

8 Dept. Agr. R. 96, 1886.

89 Appel & Riehm, Ber d. Kais. Biol Ans. f. L. u. F. Heft, 8, 1908.

% Stewart, F. C., N. Y. (Geneva) B. 328: 352.

91 Waite, M. B., Journ. Myce. 7: 105, 1902.

92 Miyabe, K., Trans. Sappora Acad. Sci. 1: 1909.

% Davis, J. J., Science, 31: 752, 1910.

94 Clinton, G. P., Ct. R. 336: 1904, 1905.

9 Rostewzew, Ann. Inst. Agron. Moscow, 9: 47 and Flora 92: 405, 1903.

96 Clinton, G. P., Ct. R. 23: 277, 1899.

7 Hume, H. H., Fla. R. 30, 1900.

9 Orton & Garrison, 8. C. B. 116: 7, 1905.

9 Halsted, B. D., Bot. Gaz. 14: 149, 1889.

10 Farlow, W. G., Bot. Gaz. 14: 187, 1889.

101 Selby, A. D., Bot. Gaz. 27: 67, 1909.

102 Stewart, F. C., N. Y. (Geneva) B. 119: 158, 1897.

103 Arthur, J. C., N. Y. (Geneva) R. 4: 253, 1885.

104 Halsted, B. D., N. J. B. 70.

105 Whetzel, H. H., N. Y. (Cornell) B. 218: 1904.

16 Taylor, T. R., D. Agr. 193, 1872.

107 Trelease, Wm., Trans. Wis. Acad. Sc. 6: 7, 1881-1884.

108 Wis. R. 16: 34, 1883.

109 Shipley, A., B. 19: Miss. Kew. 1887.

110 Stewart, F. C., French, G. T., & Wilson, T. K., B. N. Y. (Geneva)
805: 394, 1908.

111 Rostrup, Zeit. 2: 1, 1892.

112 THE FUNGI WHICH CAUSE PLANT DISEASE

u2 Magnus, P., Hedw. 149, 1892.

113 Massee, G., Jour. Linn. Soc. Bot. 24: 48, 1887.

114 Barrett, O. W., R. Porto Rico 398, 1904.

115 Raciborski, M., Ber. d. Deut. Bot. Ges. 15: 475, 1897.

118 Spegazzini, C., Rev. Argent. Hist. Nat. 1: 36, 1891.

u7 Magnus, P., Ber. d. Deut. Bot. Ges. 28: 250, 1910.

us Taplin, W. H., Amer. Florist 21: 587.

19 ©, R. Acad. Sci. Paris, 136: 472, 1906.

120 Blakeslee, A. F., Proc. Acad. Art. & Sci. 40: 1904.

121 Halsted, B. D., Amer. Flor. 13: 117.

122 Stewart, F. C., N. Y. (Geneva) B. 328: 342.

123 Halsted, B. D., N. J. B. 76: 1890.

124 Orton, W. A., Sc. 29: 916, 1909.

125 Kirk, T. W., N. Zeal. D. Agr. R. 77: 1909.

126 Swingle, D. B., B. P. I. 37: 1908.

127 Kew Bull. 871, 1897.

128 Rept. Mic. Vio., N. S. Wales, 1909.

129 Thaxter, R., Rhodora 99: 1903.

130 Atkinson, G. F., N. Y. (Cornell) B. 94: 252: 1895, also Bot. Gaz.
19: 47, 1894.

131 Gussow, Ottawa B. 63, 1909.

132 Trow, A. H., Ann. Bot. 18: 541, 1904.

133 Tdem, 15: 269, 1901.

134 Rosenberg, O., Bihand till K. Svens Vet. Akad. Handl. 28: 10, 1903.

135 Gruber E., Ber. d. Deut. Bot. Gaz. 19: 51, 1901.

138 Edgerton, C. W., La. B. 126: 1911.

137 Smith, E. G., Se. 30: 211, 1909.

28 McCallum, W. B., Ariz. R. 583, 1909.

3° Halsted, B. D., N. J. R. 1893, 393.

140 Stevens, F. L., Bot. Gaz. 38: 300, 1904.

141 Bubak, Fr., C. B. 8: 817, 1902.

12 Magnus, P., C. Bak. 9: 895, 1902.

143 Tarlow, W. G., Bus. Inst. 1: 415, 1871.

“4 Scribner, F. L., D. Agr. R. 96, 1886 and 88, 1887.

145 Stewart, F. C., Eustace, H. J. & Sirrine, F. A., N. Y. (Geneva) B.
241: 1908.

146 Morse, W. J., Me. B. 169: 1909.

17 Jones, L..R., Vt. B. 72: 1899.

46 Stewart, F. C., Eustace, H. J. and Sirrine, F. A., N. Y. (Geneva) B.
264: 1904.

“9 Farlow, W. G. B. Bussey, Inst. 415, 1876.

ASCOMYCETES (p. 64) * ” #® 25 46, 92, 58, 62

The distinguishing mark of this group is the ascus. This in its
typical form is shown in Fig. 73, as a long, slender or club-shaped
sac in which the spores are borne. The number of spores in the
ascus is usually definite and is commonly of the series, 1, 2, 4, 8,
16, 32, 64, etc., the most common number being 8. The spores
vary in size, color, shape, markings and septation. The asci
in most genera are arranged in a definite group, a layer, con-
stituting the hymenium which may be either
concave, convex, or flat. Between the asci in the
hymenium are often found slender hyphal threads
of various form, the paraphyses, Fig. 73.

The hymenium may be borne in or upon 2
firm substratum of woven threads, the stroma,
or upon a very tenuous substratum, the subicu-
lum, or without any definite subascal structure.
The stromata vary widely in character, size, tex-
ture, color, surface, form, etc.

' The mycelium is usually abundant, branched
and septate, the septation readily distinguishing
this group from the Phycomycetes. In many
species the mycelium weaves together into a false =i
parenchyma and constitutes relatively large yp. 73.— Portion
spore-bearing structures. Fig. 74. —

The ascigerous organ, ascocarp, or ascoma, paraphyses. Af-
if saucer-shaped and open is an -apothecium, Her Shami berlin
Fig. 92; if closed a perithecium, Fig. 144. In other cases, the
ascigerous layer covers the exterior surface. Fig. 74.

On the boundary lines between the Ascomycetes and other groups
are fungi which do not present the typical Ascomycete picture
but which are regarded as probably belonging to the group, i.e.,
transition forms between this and other groups. Among such are

113

114 THE FUNGI WHICH CAUSE PLANT DISEASE

forms in which the asci are without either stroma or covering,
(Protodiscales, p. 125); others in which the asci are not even in
groups but are scattered irregularly throughout the ascocarp
(Aspergillales, p. 164); and still others with the asci neither in
regular groups nor covered (Protoascomycetes, p. 119). One
further deviation from the typical form occurs in the Hemiascomy-

Sidhe oa

Fic. 74.—The large ascocarp of the morel. After Freeman.

cetes which possess a sporangium-like structure resembling that
of the typical Zygomycete; but a mycelium like that of the typical
Ascomycetes. This is by many regarded as the transition form
bridging the gap between and indicating the kinship of these two
groups; a view strongly supported by the existence of very similar
sexual processes in the two groups.

Besides the ascus the Ascomycetes possess many other kinds of

THE FUNGI WHICH CAUSE PLANT DISEASE 115

reproductive structures in the form of conidia. These may be

borne singly or in rows on simple or branched conidiophores.
The conidiophores may be single or variously grouped in columns

or layers. Figs. 352, 378, 382. In some instances they are very

Fic. 75.—Spherotheca castagnei. Fertilization and de-
velopment of the perithecium. Og=odgonium, an=
antheridium, st=stalk-cell. 6 as the ascogonium
derived from the oégonium. After Harper.
short, innate; again they are long, loose or floccosc. They may
emerge through stomata singly or in tufts or they may form sporo-
genous cushions below the epidermis or again they may be borne
inside of a hollow structure, the pycnidium, which covers them.
Chlamydospores are also found.
One or several distinct types of
sporification may belong to one
species of Ascomycete. These dif-
ferent forms of spores may appear
simultaneously on the same myce-
lium or they may follow in definite

5 i Fic. 76.—Boudiera. Six sets of
succession regulated by the changes “Suslorgans.. After Claussen.

in environment, or again one or
more of the spore forms belonging to the life history of the fun-
gus may be omitted for long intervals to appear only as the
result of stimuli of which little is yet known.

The conidia and chlamydospores are asexual spores. Sexuality

116 THE FUNGI WHICH CAUSE PLANT DISEASE

in the great majority of Ascomy-
cetes has not been investigated;
but in some species fertilization is
known to occur; in many species,
at least in form similar to that
shown by the Phycomycetes, it is
absent, probably having been lost
by degeneration or else very much
modified.

In some of the Discomycetes
there is one or more carpogonia

Fic. 77.—Later stage showing asci par : . a
and ascophores. After Claussen. and fertilization is through a tri-

chogyne by spermatia; a mode often met among the lichens.
In Pyronema,’ Fig. 78, the carpogonium is multi-nucleate and itis
fertilized by amulti-nucleate antheridium through atrichogyne. Fu-

Fic. 78.—Pyronema confluens. A. the sex or, = 00 i ichogyn
Pyro f . A. gans, og = odgonium, t= trichogyne.
B. fertilization stage in section through young apothecium, asc=asci, asf=as-
cogenous filament. After Harper.

sion of nuclei is probably in pairs as in Albugo bliti of the Phycomy-
cetes. In Boudiera? a very similar relation is found. Figs. 76, 77.

In some Perisporiales * an uninucleate odgonium is fertilized by
an uninucleate antheridium. Fig. 75.

THE FUNGI WHICH CAUSE PLANT DISEASE 117

The odgonium after fertilization gives rise to a more or less
complicated system of ascogenous hyphae, very simple in the
Erysiphacex, very complex in some Discomycetes, which produces
the asci. The sterile parts of the ascocarp, the paraphyses and
enveloping structures, arise from parts below the oégonium and
antheridium.

The very young ascus usually receives two nuclei from the parent
strand of the ascogenous hypha. These nuclei unite giving the

Fie. 79.—Tip of ascus
of Erysiphe showing : .
delimitation of asco- Fic. 80.—Later stage than

spore from asco- fig. 79, showing well de-
plasm by astral fined spore-wall. After
rays. After Harper. Harper.

primary-ascus-nucleus. This by successive mitoses affords the
single spore-nuclei. The spores are cut out from the protoplasm
of the ascus in a most peculiar manner by reflexion of and union
of astral rays which emanate from a centrosome-like organ at the
beak of the prolonged nucleus. Figs. 79, 80.

The significance of two nuclear fusions in the life cycle of these
fungi, one following the union of the antheridium with the odgo-
nium, the other later, in the asci, is a puzzling phenomenon, the
real significance of which is not clear.

Key to SusciassEs or Ascomycetes
Asci with varying number of spores,

usually numerous.............+--- 1. Hemiascomycetes, p. 118.
Asci with definite number of spores
Asci separate or scattered. ........... 2. Protoascomycetes, p. 119.

Asci approximate, usually forming a
hymenium................---5- 3. Euascomycetes, p. 123.

‘118 THE FUNGI WHICH CAUSE PLANT DISEASE

Hemiascomycetes (p. 117)

There is a single order, the Protomycetales, which contains about
twenty-five species. Mycelium filamentous, branched, septate;
conidia present; asci sporangia-like, containing numerous spores,
terminal, naked or covered with a hyphal felt; in some species
known to originate from the fertilization of an o6gonium.

Protomycetales

Ky To Famities oF Protomycetales

Asci naked

Asci long, tubular ..............-... 1. Ascoideacee.

Asci elliptic or globular............. 2. Protomycetacez, p. 118.
Asci more or less covered by hyphe..... 3. Monascacez.

Of these families the first is found in slime flux; the last is sap-
rophytic.

Protomycetacez

Mycelium prominent; asci intercalary or terminal, large, de-
velopment arrested before spores are formed; a process which is
completed only after a period of rest.

Key to GENERA or Protomycetacee

Parasitic, intercellular in living plants...... 1. Protomyces, p. 118.
Saprophytic, building hemispheric sporing
MASSES 214 aus4urs eiew/are saa ela e ote acth ene 2. Endogone.

Protomyces Unger

Asci thick walled; after a long period of rest forming a large
mass of elliptic spores which conjugate in pairs, then germinate
immediately by a germ tube.

This genus is sometimes placed with the Phycomycetes.™

THE FUNGI WHICH CAUSE PLANT DISEASE 119

P. macrosporus Ung.

Asci globose to elliptic, 40-80 x 35-60 4; membrane yellowish,

up to 5 » in thickness, contents colorless; spores elongate-ellipsoid,
2-3 x1 yp.

It produces small galls, which are at first watery looking, then

Fic. 81.—Protomyces. A, mycelium and
young ascus; E, ascus with mature spores.
After De Bary.

brown, upon the leaves and stems of various economic and non-
economic Umbbelliferz.

P. pachydermus Thiim. affects carrots and dandelions.” P.
rhizobius Trail, grows on Poa annua in Scotland. Several other
species are found on wild plants.

Subclass Protoascomycetes (p. 117)

There is a single order, the Saccharomycetales, with about
seventy species.

Mycelium often undeveloped; asci isolated or formed at different
points on the mycelium, mainly 4-spored; spores unicellular;
asexual reproduction by gemmation or by conidia.

120 THE FUNGI WHICH CAUSE PLANT DISEASE

Key to Famiuies or Saccharomycetales

Vegetative cells single or loosely

attached in irregular colonies,

mycelium not usually developed,

asci isolated, not differentiated

from vegetative cells. ......... 1. Saccharomycetacee, p. 120.
Vegetative cells forming a mycelium, '

asci terminal, or intercalary,

differentiated from mycelium.. 2. Endomycetacee, p. 122.

The first family, the yeasts, to which belong the majority of the
species of the order, is of prime importance in fermentation. A

Ets
Fic. 82.—Yeast plant-bodies, showing

budding and sporulation. After
Coulter and Rees. :

few species are known to cause animal diseases; others are found
associated with the slime fluxes.

Saccharomycetaceze

Vegetative cells separate or few together, never truly filamen-
tous, propagating by buds; asci globose to elliptic, 1 to 8-spored;
growing typically in sugary or starchy materials.

THE FUNGI WHICH CAUSE -PLANT DISEASE 121

Key To Genera or Saccharomycetacere

Vegetative cells globose, ovoid, pyriform, etc.
Vegetative cells increasing by budding;
asci typically 3 10 4 spored.
Spores globose or ovoid.
Spores upon germination forming
typical yeast cells.
Ascus formation preceded by the
conjugation of like gametes.
Ascus formation not preceded by
the conjugation of gametes.
Spore membrane single. .......
Spore membrane double. ......
Spores upon germination forming a
poorly developed promycelium.
Spores pileiform or limoniform, costate
Spores hemispheric, angular or irregular
in form, upon germination forming
an extended promycelium........
Vegetative cells increasing by fission; asci
S-spored. . 0.0... 00. c ccc eee
Vegetative cells elongate, cylindric; spores
filiform,
Asci I-spored.......... 0.0.0 e eee ee eae
Asci 8-spored..............00 ccc eee

. Zygosaccharomyces.

. Saccharomyces, p. 121.
. Saccharomycopsis.

. Saccharomycodes.

. Willia.

. Pichia.

. Schizosaccharomyces.

. Monospora.
. Nematospora, p. 122.

Saccharomyces Meyen

Vegetative cells globose, ellipsoid, ovate, pyriform, etc., repro-
ducing by budding and remaining attached in short, simple or
branched pseudo-mycelial groups, at length separating; asci
globose, ellipsoid, or cylindric, 1 to 4-spored (typically 3 to 4
spored), single or in chains; spores globose to ellipsoid, continuous.

Many species, chiefly saprophytes.

S. croci Roze is described as the cause of a crocus disease.4

From sorghum plants suffering from blight a yeast was isolated
by Radais.’ This when inoculated in pure culture into healthy
plants produced the characteristic lesions and effects.

122 THE FUNGI WHICH CAUSE PLANT DISEASE

Nematospora Peglion (p. 121)

Colonies (in culture) disciform; cells elongate; asci cylindric,
8-spored; spores filiform, continuous, long-ciliate, hyaline.

Monotypic.

N. coryli Pegl.,° the cause of malformation of the hazel nut in
Italy, is a peculiar fungus with what appears to be asci contain-
ing eight long slender flagellated spores.

Endomycetacez (p. 120)

Mycelium usually well developed, often producing a luxuriant
growth, multiseptate; asci borne singly on branches, or inter-
calary, 4 to 8-spored; spores one-celled; conidia produced apically,
unicellular.

Key To GENERA oF Endomycetacer

Mycelium poorly developed, parasitic on

Mucoralesy:s:si5.05.¢ssae 005s seek Ges es 1. Podocapsa.
Mycelium well developed
Asci formed after conjugation of a pair of
spirally entwined branches. ........ 2. Eremascus.

Asci formed asexually, produced termi-
nally, rarely intercalary.
Asci 4-spored.............-.20..0005 3. Endomyces, p. 122.
Asci 8-spored..............0--20.05. 4. Oleina.

Endomyces Rees

Mycelium well developed, byssoid; asci
borne singly on the ends of short lateral
branches, globose to pyriform, 4-spored,
Fe spores continuous.

NS cite The members of this genus are of ques-

Co) tionable importance as parasites. Some
ie ee ies are commonly found in sap exuding from

sacs of E, mali, spores tfee wounds” where they, together with

ee pone in these. other fungi present, set up a fermentation

the products of which prevent the wound

from healing and result in injury. One species has been re-
ported in America as an active parasite on apples.

THE FUNGI WHICH CAUSE PLANT DISEASE 123

E. mali Lewis”

Mycelium well developed, multiseptate; conidia formed on
short conidiophores or on the ends of short germ tubes, averag-
ing 3 x 8 yw; no yeast-like budding; asci usually
on short lateral branches, 11-14 yw in diameter;
ascospores spheroidal, slightly elongate, 4.5 x
5.5 » with thickened places on the walls, brown
when mature. Figs. 83, 84. Fi. 86 ak:

Lewis isolated the fungus from decayed spots Typical manner

i of bearing conidia
on apples by plate cultures. Inoculations proved on agar. After
that it is capable of causing a slow decay with- Lew
out the aid of other fungi. An extensive cultural study as well as
a considerable cytological study was made.

E. decipiens (Tul.) Rees is parasitic on Armillaria; E. parasitica
Fayod on Tricholoma.*® *”

Euascomycetes (p. 117)

This is an extraordinarily large group comprising some 16,000
species, with great variety of size, color and shape of plant body.
Most of them are saprophytes, still many are parasites either in
their ascigerous or their conidial stages of development.

The twelve orders may be recognized by the following key.

Kery To Orpers oF Euascomycetes

Asci approximate in an indefinite hyme-
nium, NO ascoma. ...........+-+e ees 1. Protodiscales, p. 125.
Asci grouped in a definite ascoma
Asci collected in a flattened, concave or
closed ascoma, often bordered by a
distinct layer
Ascoma at maturity open and more or
less cup-like. Discomycetes
Ascoma open from the first, clavate or
convex, pitted, or gyrose....... 2. Helvellales, p. 130.
Ascoma at first closed, opening early,
without special covering, more
or less fleshy............-+--- 3. Pezizales, p. 133.

124 THE FUNGI WHICH CAUSE PLANT DISEASE

Ascoma opening tardily, enclosed by
a tough covering which becomes
torn open at the maturity of the
spores
Ascoma roundish, opening by stel- .
late or radiating fissures. .... 4. Phacidiales, p. 154.
Ascoma elongate, opening by a
longitudinal fissure. ......... 5. Hysteriales, p. 159.
Ascoma at maturity closed and tuber-
like, subterranean,..........---- 6. Tuberales.
Asci collected in a cylindric or globose
perithecium
Perithecia sessile, solitary and free, or
united and embedded in a stroma
Asci arranged at different levels in
the perithecium. ............. 7. Aspergillales, p. 164.
Asci arising from a common level
Mycelium superficial, perithecia
scattered, globose and without
apparent ostiole, or flattened
and ostiolate............... 8. Perisporiales, p. 170.
Mycelium nearly superficial, peri-
thecia ostiolate
Perithecia and stroma (if pres-
ent) fleshy or membranous,
bright colored............ 9. Hypocreales, p. 195.
Perithecia and stroma (if pres-
ent) hardened, rarely mem-
branous, dark colored
Wall of perithecia scarcely
distinguishable from the
stroma. ............... 10. Dothidiales, p. 215.
Perithecia with distinct wall,
free or embedded in the
STOMA ce we os 11. Spheriales, p. 221.
Perithecium borne on a short pedicel;
microscopic fungi parasitic on
Insects c.05 Scie ke eo ae ees 12. Laboulbeniales.

Of these all contain plant parasites with two exceptions; the
Tuberales, which bear underground tuber-like ascocarps, some of

THE FUNGI WHICH CAUSE PLANT DISEASE 125

these prized as table delicacies, and the Laboulbeniales, an order
rich in species which are all parasitic upon insects.

Protodiscales (p. 123)

The 4-8 to many-spored asci form a flat palisade-like hymenium
which arises directly from the mycelium; paraphyses none; spores,
one-celled, elliptical or round.

Key To Famiuies oF Protodiscales

Parasiti¢. 2.5.20 ¢e sei gseeceweceereuans 1. Exoascacee, p. 125.
Saprophytic. ..................0..000. 2. Ascocorticiacee.

Of these families the second contains only one genus and two

species found in bark. The first family is aggressively parasitic.
Exoascaceze ** **” #77

This is the most simple of the parasitic Ascomycetes, definitely
recognizable as such, and is comparable with the Exobasidiales
among the Basidiomycetes. All the
species are parasitic and many of
them very injurious. The mycelium,
which can be distinguished from : |’;
that of other fungi by its cells of ~ Lt
very irregular size and shape, wan-
ders between the host cells (intra- CH)
cellular in one species), or is some-
times limited to the region just fy, 35.—Exoascus showing myce-
below the cuticle. The asci develop Jliumandasci. After Atkinson.
in a palisade form on a mycelial network under the epidermis, or
the cuticle, or on the ends of hyphe arising from below the epi-
dermal cells. They are exposed by the rupture of the cuticle or
epidermis and contain four to eight hyaline, oval, one-celled
spores. These by budding, while still in the ascus, may pro-
duce numerous secondary spores, conidia, which give the im-
pression of a many-spored ascus. The ascospores also bud freely
in nutritive solutions. The primary-ascus-nucleus arises from

126 THE FUNGI WHICH CAUSE PLANT DISEASE

fusion of two nuclei as is general among the Ascomycetes. The
spore-nuclei arise by repeated mitoses of the primary nucleus.
Affected leaves, fruit and twigs become swollen and much dis-
torted; wrinkled, curled, arched, puckered. In woody twigs the
mycelium often induces
unnatural, profuse,
tufted branching result-
ing in “witches brooms”
a though such structures
Ge t often arise from irrita-
; i tion due to other causes.
o 4 Many attempts have

Fic. 86.—Taphrina showing mitoses in the young been made to arrange the
ascus leading to the development of spore- species In natural genera;

ee eine some based on the num-
ber of ascospores,” *** others largely on the biologic grounds of an-
nual or perennial mycelium.® Giesenhagen ™ whose classification
is followed here, recognizes two genera, Exoascus being merged
into Taphrina.

35.

Key to GENERA oF Exoascacese
Asci cylindric, clavate or abbreviate-cylin-
dric, produced above the epidermis of

the hosts ssa 5.62cese08 ¢seedew ge 1. Taphrina, p. 126.
Asci saccate, in epidermis................ 2. Magnusiella.

Taphrina Fries

Mycelium annual or perennial; asci 4 to 8-spored, or by germina-
tion of the ascospores, multispored, borne on the surface of blisters
and other hypertrophied areas, cylindric to clavate, or a modifica-
tion thereof. Of this genus Giesenhagen ” recognizes four series
of species which are arranged in three subgenera.

Subgenus 1. Taphrinopsis,—one series (Filicina)

The asci are slender clavate, narrowed at each end, rounded
above, broadest in the upper fourth. Parasitic on ferns. None of
the five species is of economic importance.

THE FUNGI WHICH CAUSE PLANT DISEASE 127

Subgenus. 2. Eutaphrina,—one series (Betula)

Asci broadly cylindric, rarely contracted at the base or from
the middle down, truncate above and sometimes in-sunken. On
Amentacex, chiefly Betula, Alnus, Ostrya, Carpinus, Quercus,
Populus. Of the twenty-four species of this series but few are
of importance.

T. coerulescens (D. & M.) Tul." Annual, producing blisters
on the leaves of oak, the sporing surface bluish; asci elongate,
broadly cylindric, 55-78 x 18-24 u; spores breaking up into
conidia.

On various species of Quercus in Europe and America.

T. ulmi (Fcl.) Joh., on the elm; T. aurea (Pers.) Fries on the
leaves of Populus and T. johonsonii Sad. on the fertile aments of
the aspen are among the more important remaining species of the
series.

Subgenus 3. Exoascus,—two series

Asci clavate, normally cylindric or more or less abbreviated.

(1) Prunus series on Rosacex. Asci slender, clavate, narrowed
below, broadest in their upper fourth, varying through all inter-
mediate forms to narrowly cylindric.

(2) Aisculus series, on Sapindace, Anacardiacee, etc.—Asci
broadly cylindric, short, rounded or truncate.

The more important economic species of the genus belong to
the Prunus series.

T. deformans (Fcl.) Tul.® ! 38

The irregular vegetative mycelium devoid of haustoria grows
in the leaf parenchyma and petiole and in the cortex of branches.
A distributive mycelium lies close beneath the epidermal cells of
twigs and in the pith and extends some distance through the twig.
Fig. 87. Branches arise from the vegetative mycelium, penetrate
between the epidermal cells to the cuticle and then branch freely
to form a network of short distended cells beneath the cuticle.
This is the hymenium, a layer of ascogenous cells. These cells
elongate perpendicularly to the host’s surface, Fig. 85, rupture
the cuticle, and form a plush-like layer. The protoplasmic con-

128 THE FUNGI WHICH CAUSE PLANT DISEASE

tents crowds toward the tips of these cells and a basal septum cuts
off the ascus proper from the stalk cell, Fig. 88. The spores then
form within the ascus. The ascospores may bud either before
or after extrusion
from the ascus, pro-
ducing conidia, which
may themselves bud
indefinitely, producing
secondary, tertiary,
ete., crops. In this
condition the conidia
strongly resemble
yeast cells. On the
host plant ascospores
germinate by germ
tubes, which are ca-
pable of infecting
proper hosts. No
success has rewarded
‘ attempts to secure
germ tubes from co-
nidia. Leaf infection
is chiefly external;
rarely internal from
mycelium perennating
in the twigs. It oc-
curs when the leaf is
very young. Infected
leaves are thickened
Fic. 87.—T. deformans. 5, distributive hypha; and broadened and

1, vegetative hyphz; 9, sporiferous hyphe. After the tissues are stiff

Pierce. 5

and coriaceous. The

palisade cells increase in size and number and lose their chloro-
phyll. Blistering and reddening of the leaves follows.

Asci clavate, 25-40 x 8-11 y; spores 8, subglobose or oval,
3-4 yp. On the peach in Europe, North America, China, Japan,
Algeria and South Africa.

T. pruni (Fel.) Tul® ™ is found in Europe and North America

THE FUNGI WHICH CAUSE PLANT DISEASE 129

on plum and wild cherry, causing “plum pockets.” The ovary is
the seat of attack. The mycelium after bud infection pervades
the mesocarp which hypertrophies and alone produces a much
enlarged fruit, usually with entire sacrifice of the other fruit parts.
Asci are formed over the diseased surface much as in the last
species. The mycelium is perennial in the bast and grows out into
the new shoots and
buds each spring. In-
fection also reaches
other shoots and trees
by means of the spores.

Ascus elongate-cylin-
dric, 30-60 x 8-15 u;
spores 8, globose 4-5 yu.
Perennial.

T. cerasi (Fel.) Sad.® 15
produces the witches
broom effect upon culti-
vated and wild cherries.
It is common in Eu-
rope, rare in America.
Perennial; asci clavate
30-50 x 7-10 yu; spores
8, forming conidia in
the ascus, oval, 6-9 x Fic. 88.—T. deformans. Young and old asci.

5-7 po After Pierce.
On Prunus avium, P. cerasus, etc. in North America and
Europe.

T. mirabilis (Atk.) Gies.* * grows on leaf buds and twigs of
Prunus angustifolia, P. hortulana, P. americana in North America.

Perennial; sporing on the fruits and tips of branches of the host;
asci subcylindric, blunt above, 25-45 x 8-10 yu; spores 8, ovate.

T. longipes (Atk.) Gies. is on Prunus americana in North
America, causing plum pockets.’

Perennial; sporing on young fruits; asci cylindric, truncate or
not, 30-40 x 7-10 y; spores 8, globose or ovate, 3-4 pn.

T. rhizipes (Atk.) Gies. ‘Known only in North America, caus-
ing pockets on Japanese plums; ® probably of wider distribution.

130 THE FUNGI WHICH CAUSE PLANT DISEASE

Perennial; asci cylindric, or club-shaped, 30-40 x 8-10 u,
appearing to have basal rhizoids; spores 8, globose.

T. communis (Sad.) Gies.2 Perennial in branches; sporing on
immature fruits; asci clavate, 24-45 x 6-10 u; spores 8, elliptic,
5 x 3-4 yu, often producing conidia.

On Prunus americana, P. maritima, P. nigra, and P. pumila, in
North America.

T. institie (Sad.) Joh. Forming witches brooms on Prunus
institia, P. domestica, and P. pennsylvanica in Europe and
America.®

Perennial; sporing on the under side of the leaf; asci clavate to
cylindric, 25-30 x 8-10 u; spores 8, not rarely producing conidia,
globose, 3.5 yu.

T. decipiens (Atk.) Gies. On Prunus americana in North
America®

Perennial; sporing on under surfaces of leaves; asci irregularly
clavate, often almost cylindric, 20-40 x 10 u; spores breaking up
into conidia.

T. bullata (Fel.) Tul. On pear and Japanese quince.

Annual; asci clavate, 36-40 x 8-9 uw; spores 8, often forming
conidia, globose, about 5 yp.

T. farlowii (Sad.) Gies.® is found on Prunus serotina in America;
T. minor Sad. on leaves of Prunus chamecerasus and P. cerasus,
in Germany and England. It has recently caused considerable
damage in South England.

T. bassei Fab. causes witches broom of cacao in Kamerun.

T. rostrupiana (Sad.) Gies. is on Prunus spinosa;

T. crategi (Fcl.) Sad. on Crategus oxycantha.

T. maculans Butler is reported on Tumeric and Zinzibar by
Butler.* T. theobrome Ritzema Bos. is reported as injurious to
the cacao tree.

Many other species of Taphrina of minor importance occur upon
alder, poplar (Populus), Carpinus, birch, elm, maple, hawthorn,
oak and numerous other hosts.

Helvellales (p. 123)

Ascoma fleshy, separable into a definite hymenium of asci and
paraphyses and a stroma which is usually large and stalk-like;

THE FUNGI WHICH CAUSE PLANT DISEASE 131

fertile portion more or less cap-like; hymenium free from the first
or covered with a thin, evanescent veil; !” asci cylindric, opening

by an apical pore; spores ellipsoid, colorless or light yellow, smooth,
or in one genus echinulate.

Key To Famiuies or Helvellales

Ascocarp stalked
Fertile portion clavate or capitate; asci
opening by an irregular slit.......... 1. Geoglossaceg, p. 131.
Fertile portion pileate; asci opening by alid. 2. Helvellacee.
Ascocarp sessile... .......... 0.002 c cee eee 3. Rhizinacez, p. 132.

The majority of the species of this order are saprophytes, the
only parasites being of the first and third families. Of the second
family many of the species are edible and some are very large.

Geoglossacez

Key To TRIBES AND GENERA OF Geoglossacee

Ascoma clavate or spatulate, ascigerous
portion usually more or less com-
pressed, rarely subglobose.... Tribe I. Geoglossex.
Ascoma clavate, fertile portion at most
only slightly decurrent
Spores small, elliptic, cylindric or
fusiform, continuous; plants
bright colored ................ 1. Mitrula, p. 132.
Spores long, elliptic to cylindric, 3 to
many-septate at maturity

Hymenium bright colored ........ 2. Microglossum.
Hymenium black or blackish
Spores hyaline ............---- 3. Corynetes.
Spores brown. .........-+--+-- 4. Geoglossum.

Ascoma spatulate or fan-shaped, as-
cigerous portion decurrent on the stipe
Ascigerous only on one side of the

BEM, 09 ccc ee ieee ees 5. Hemiglossum.
Ascigerous on both sides the stem

Spores globose .........-----+- 6. Neolecta.

Spores elongate .........-.---- 7. Spathularia.

Ascoma stalked, capitate or pileate, in one
genus sessile... . 6.6.0... eee eee eee II. Cudoniez.

132 THE FUNGI WHICH CAUSE PLANT DISEASE

Mitrula sclerotiorum Rost.¥
which causes a disease of alfalfa in
Denmark is the only pathogen of
the family. The infected plants die
and later the roots and stems be-
come filled with black sclerotia
which lie dormant about a year.
Fic. 89.—Mitrula. B, habit Upon resuming growth they be-
sketch; F, asci. After Schréter. “

come covered by light. red eleva-

tions, which bear small light red ascocarps.

Rhizinacee (p. 131)
Key to Genera or Rhizinacese

Spores elliptic or spindle-shaped:

Without rhizoid-like structures. ......... 1. Psilopezia.
With rhizoid-like structures............. 2. Rhizina, p. 132.
Spores globose ..............0000 eee eeeee 3. Sphzrosoma.

Only one genus, Rhizina, causes
disease.

Rhizina Fries with some eight
species is recognized by its: crust-
formed, sessile, flat ascophore with
root-like outgrowths from the lower
side. Fig. 90. Asci cylindrical, 8-
spored, opening by a lid; spores one-
celled, hyaline; paraphyses many. It
is often purely saprophytic, growing
in burned-over spots in forests.

R. inflata “(Schaff) Quel.’® © is
counted as the cause of serious root Fi¢- 90-—Rhizina inflata. B, asco--

: . carp from below; C, asci and
diseases of forest trees, especially paraphyses. After Schréter and
conifers, in Europe. The fungus also ee 3
occurs in Asia and America.

R. undulata causes death of fir seedlings.”

THE FUNGI WHICH CAUSE PLANT DISEASE 133

Pezizales (p. 123)

In this order unlike the last, the hymenium is at first enclosed
but soon becomes exposed. The apothecia at maturity are typi-
cally disc or saucer-shaped (Fig. 101) or sometimes deeper, as
cup, beaker or pitcher-shaped. They vary from a size barely
visible up to 8-10 cm. in diameter. Some are stalked, more often
they are sessile. In consistency they vary from fleshy or even
gelatinous to horny. Paraphyses are present and may unite over
the asci to form a covering, the epithecium. The apothecium may
be differentiated into two layers; the upper bearing the asci is the
hypothecium, the lower the peridium. In some cases sclerotia
are formed. Many species possess conidiospores as well as asco-
spores, borne either on hyphe or in pycnidia. The great majority
are saprophytes, a few are parasitic. There are some three thou-
sand species.

Key to Famities or Pezizales

No lichenoid thallus and no algal cells
Ascocarps free, solitary or cespitose
Ascocarps fleshy or waxy, rarely gelati-
nous; ends of paraphyses free
Peridium and hypothecium without
distinct lines of junction
Ascoma open from the beginning,
convex; peridium wanting or
poorly developed. .......... 1. Pyronemacee.
Ascoma concave at first; a fleshy
peridium present.
Asci forming a uniform stratum,
at maturity not projecting. 2. Pezizacez.
Asci projecting from the ascoma
at maturity.............. 3. Ascobolacee.
Peridium forming a more or less dif-
ferentiated membrane.
Peridium of elongate, parallel
pseudo-parenchymatous, hya-
line, thin-walled cells ....... 4. Helotiacee, p. 134.

134 THE FUNGI WHICH CAUSE PLANT DISEASE

Peridium firm, of roundish or angu-
lar, pesudo-parenchymatous,
mostly dark, thick-walled cells 5. fener p. 146.
Ascocarps leathery, horny or cartilagi-
nous; ends of the paraphyses united
into an epithecium
Peridium wanting or poorly devel-
OPO: o.ccevese. oes kane es 6. Celidiacez.
Peridium well developed, mostly
leathery or horny
Ascccarps free from the beginning,
dish or plate-shaped, never en-
closed by a membrane. ...... 7. Patellariacez.
Ascocarps at first embedded in a
matrix, then erumpent, urceo-
late or cup-shaped, at first en-
closed in a membrane which
disappears later... ......... 8. Cenangiacee, p. 150.
Ascocarps borne on a highly developed
stringy or globoid stroma
Ascocarps at the ends of the branches

of a cord-like stroma............ 9. Cordieritidaceee.
Ascocarps embedded in the upper por-
tion of a globoid stroma......... 10. Cyttariacez.

Lichenoid thallus more or less prominent,
algal cells typically present, asci disap-
pearing early, disk with a mazedium.. 11. Caliciacez, p. 153.

The Pyronemacez, Peziacee, and Ascobolacee are pure sapro-
phytes on organic matter in the ground or on rotting wood. The
Patellariacee are largely, and the Celidiacex are nearly all, para-
sitic on lichens. The Cordieritidacee of four species, possessing
astony stroma, are unimportant. The Cyttariacex, of one genus,
and some six species, are limited to the southern hemisphere where
they grow on branches of the beech.

Helotiacee (p. 133)

In members of this family there is a distinctly differentiated
peridium. The apothecia are usually fleshy or waxy, superficial,
first closed, later opening; the paraphyses form no epithecium.
Asci 8-spored. Spores round to thread-shaped, one to 8-celled,

THE FUNGI WHICH CAUSE PLANT DISEASE 135

hyaline. Some of the genera are among the most serious of
plant pathogens. About one thousand species.

Key To GENERA oF Helotiaceze

Ascocarps fleshy, fleshy-waxy, thick ormem-
branous
Ascocarps fleshy-waxy, brittle when fresh,
leathery when dry. ...............
Ascocarps felty hairy externally. .....
Ascocarps covered with bristle-like hairs
externally.................0000.
Ascocarps naked
Ascocarps springing from a sclero-

Ascocarps not springing from a
sclerotium
Spores 1-celled
Substratum green.............
Substratum uncolored. ........
Spores at length 2 to 4-celled....
Ascocarps waxy, thick, tough or mem-
branous
Ascocarps externally hairy...........
Ascocarps resting on an extended
arachnoid mycelium
Spores I-celled.................
Spores becoming several-celled. . .
Ascocarps without arachnoid my-
celium
Spores globose..................
Spores ellipsoid or elongate
Disk surrounded by black hairs.
Disk smooth
Paraphyses obtuse at the apex
Walls of ascoma delicate;
spores mostly 1-celled,
rarely 2-celled at ma-
tUNtYs Wedec ok owes
Walls of ascoma thick;
spores 2-celled at ma-

tUTbY) o:sdacs eyes as 12.

. Sarcoscyphee.
. Sarcoscypha.

. Pilocratera.

. Sclerotinia, p. 136.

. Chlorosplenium, p. 144.
. Ciboria.
. Rutstreemia.

. Trichopezizee.

. Eriopeziza.
. Arachnopeziza.

. Lachnellula.

. Desmazierella.

. Dasyscypha, p. 144.

Lachnella, p. 145.

136 THE FUNGI WHICH CAUSE PLANT DISEASE

Paraphyses lancet-shaped at

apex
Spores l-celled........... 13. Lachnum.
Spores at length several-
celled... ..........5.- 14. Erinella.
Ascocarps naked. ..........-..+--++: III. Helotiez.
Spores globose...........-.---+--+ 15. Pitya.
Spores ellipsoid or fusiform
Spores 1-celled
Border of disk smooth. ........ 16. Hymenoscypha, p. 146.
Border of disk toothed........ 17. Cyathicula.

Spores at length 2 to 4-celled
Ascocarps sessile, rarely com-
pressed at base........... 18. Belonium.
Ascocarps stalked, or at least
compressed like a stalk
Walls of ascoma waxy; stem

short and delicate....... 19. Belonioscypha.
Walls of ascoma waxy, thick;
stem thick............. 20. Helotium.
Spores filiform
Ascocarps sessile. .............--. 21. Gorgoniceps.
Ascocarps stalked. .............. 22. Pocillum.
Ascocarps gelatinous gristly, horny when
GPs: sea tedsar kien seed ee eee IV. Ombrophilez.

Of these genera only the five given below have parasitic represen-
tatives of economic importance, while only one to two others are
parasitic. The rest grow as saprophytes on rotting wood and
organic debris in the soil.

Sclerotinia Fuckel (p. 135)

This genus contains several very important pathogens, some
of them preying upon a wide range of hosts and causing great loss.
A striking feature of the genus is the sclerotium which is black and
borne within the host tissue or upon its surface. From the sclerotia
after a more or less protracted period the apothecia develop. These
are disc-shaped and stalked. The asci are 8-spored; spores elliptical
or fusiform, unicellular, hyaline, straight or curved. Some species

THE FUNGI WHICH CAUSE PLANT DISEASE 137

possess Botrytis forms (see pp. 141 and 578), others Monilia (see
pp. 139 and 558) forms of conidial fructification. In addition to ”
these there may be gonidia, which appear to be
degenerate, functionless conidia. In some species
there is no known spore form except that in the
ascus.

8S. ledi Now. is of especial interest as the one

.fungus outside of the Uredinales that exhibits
heteroecism.**?

Many forms found upon separate hosts and
presenting slight differences under the micro-
scope, often even no microscopic differences,
have been named as separate species. Only
long careful culture studies and inoculation ex-
periments will determine which of these species
are valid, where more segregation, where more
aggregation is needed. Hie ish oe

The mere association of Botrytis or Monilia wath disjunctors.

oe. i Bae Scat er Woronin.
conidial forms with Sclerotinia, in the same host,
has repeatedly led to the assumption that such forms were genetic-
ally connected. Such assumptions arenot warranted. Only themost
careful study and most complete evidence justify such conclusions.

The genus contains some fifty species which are divided into two
subgenera; Stromatinia Boud., forming sclerotia in the fruits of
the host; Eusclerotinia Rehm forming sclerotia in or on stems
and leaves of the host.

When conidia are known those of Stromatinia are of the Monilia
type and those of Eusclerotinia of the Botrytis type. Each group
contains important economic species.

S. fructigena, S. cinerea and S. laxa.

These forms are perpetuated chiefly by their conidia. The
ascus-forms are much less often seen.

When the conidia fall upon the peach, the mycelium develops
and penetrates even the sound skin, then rapidly induces a brown
rot. The mycelium within the tissue is septate, much branched,
and light brown in color. It soon proceeds to form a subepidermal
layer and from this the hyph arise in dusty tufts of Monilia-form
conidiophores and conidia (Fig. 92). The earlier conidia are thin-

20, 21, 25, 291-295

138 THE FUNGI WHICH CAUSE PLANT DISEASE

walled and short lived, the later ones thicker walled and more
enduring.

After some weeks these tufts cease forming and disappear. The
mycelium within the fruit persists, turns olivaceous and forms
large irregular sclerotioid masses which on the following spring
may produce fresh conidia.

These sclerotioid (mummified) fruits under suitable conditions

LY
¥
Vy} f NG wath
et Liane

|
OCT
rN HD
Ke

Fic. 92,—Selerctinia on plum. a, section showing a spore pustule and chains
of conidia; b, part of a spore-chain; c, spores germinating; d, a mummy
plum and ascophores; e, an ascophore; f, ascus; g, mature spores. After
Longyear.
in nature, usually at blossom time of the host, can also produce
apothecia, a fact first demonstrated by Norton.22
These apothecia develop in large numbers from old fruits half
buried in soil, and send forth ascospores to aid in infection. The
ascospores germinate readily in water and it was proved by Norton
that they give rise to a mycelium which produces the characteristic
Monilia. Inoculation of ascospores on fruit and leaves also gave
positive results in two or three days. The flowers, and through
them the twigs, are also invaded by the mycelium which seeks
chiefly the cambium and bast. Shot-hole effect is produced on
leaves of peach and cherry (Whetzel 2%). Infection is frequently
through minute wounds.*4

THE FUNGI WHICH CAUSE PLANT DISEASE 139

On the apple the fungus shows two different modes of develop-
ment. In some cases the mycelium accumulates under the epider-
mis without producing spores, becomes dark colored and also
causes a darkening of the contents of the host cells, which results

in a black spot giving rise to the name black
rot. In other cases*> the mycelium produces a
brown rot and abundant conidial tufts, ar-
ranged in concentric circles around the point
of infection.

The form on pomaceous fruits has long been
regarded as identical with that on stone fruits;
but recently, at least in Europe, they have been
distinguished on cultural and morphological
grounds*® (see also 2’), as separate species,
the most distinctive character perhaps being
the color of the mass of conidia. In a similar
way S. laxa Ad & Ruhl. is set aside as a distinct
only apricots.!?4

Fic. 93.—S. fuckeli-
ana, attachment
organ. After Ist-
vanfii.

species infecting

American mycologists are inclined to doubt the distinctness of

the species on drupes and pomes in this country.

S. fructigena (Pers.) Schr.

Apothecia from sclerotia
in or on mummied fruits,

averaging 20.9 x 12.1 un.

Fic. 94. atypia conid- §, cinerea (Bon.) Wor.
iophore and conidia

produced either
0.5-3 cm. high,

stem dark brown, disk lighter, 5-8 or even
15 mm. in diameter; asci 125-215 x 7-10 py;
spores ellipsoidal, 10-15 x 5-8 yu.

Conidia (=Monilia fructigena Pers.). Co-
nidiophores covering the fruits of the host
with a dense mold-like growth of light
brownish-yellow or ochraceous color; spores

On stone and

pome fruits, especially the latter.

of the Botrytis-form Apothecia and asci similar to those of

of S. fuckeliana. Af-

cae Rete S. fructigena, Conidia (

=Monilia cinerea

Bon.). Conidiophores covering the fruits
with a dense grayish mold-like growth; spores averaging 12.1 x

8.8 uw. On stone and pome fruits, especially the

former.

140 THE FUNGI WHICH CAUSE PLANT DISEASE

S. linhartiana P. & D.* is reported on quince in France. S.
mespili Schell on medlar. S. seaveri, Rehm., conidia =Monilia
seaveri, is on Prunus serotina.!8 s

S. padi Wor. is found on Prunus padus and Castanea.

It possesses a Monilia-form conidial stage with typical dis-
junctors, i. e., spindle-shaped cellulose bodies between the conidia
which easily break across to facilitate the separation of the conidia.

Fic. 95.—S. libertiana. Sclerotia produced in artificial cul-
ture. After Stevens and Hall.

S. oxycocci Wor. is found on cranberry. It is unique in that
half of the spores in each ascus are larger than the others. The
conidial stage is a Monilia.

S. fuckeliana (De Bary) Fel.”

Apothecia in clusters of 2-3 from sclerotia in the leaves, rarely
in the fruits, of the host, yellowish-brown, 0.5-4 u across, stem
slender; ascospores 10-11 x 6-7 u.

Conidia (=Botrytis cinerea Pers., B. vulgaris Fr.). Conidio-
phores simple or branched, forming dense gray tufts; conidia sub-
globose, usually minutely apiculate, almost hyaline, 10-12 u.
Fig. 94. ?

7

THE FUNGI WHICH CAUSE PLANT DISEASE 141

It causes a rot of the grape, much dreaded in Europe, attacking
leaves, fruit and stem. The fungus can persist long as a sapro-
phyte in the conidial condition. Sclerotia are borne within the
affected tissues. On germination they may either produce the
conidia directly or form apothecia. . Both ascospores and conidia
are capable of infecting the grape but infection is much more
certain from a vigorous mycelium (see S. libertiana, p. 142).

Attachment organs, c. f. Fig. 93, which consist of close branch-
clusters and seem to be induced by contact of a mycelial tip with
any hard substance are present in abundance. Both toxins and
digestive enzymes are produced. *

Botrytis douglasii on pine is perhaps identical with the conidial
form of the last fungus (see p. 140) as may also be the Botrytis of
Ward’s Lily Disease; *° the Botrytis causing disease of goose-
berries #! and many others that have been named as distinct
species of Botrytis.

S. galanthina Ludwig, close kin to 8. fuckeliana, attacks snow-
drops. S. rhododendri Fisch. occurs on Rhododendron.

The former of these two is supposed to be the ascigerous form
of Botrytis galanthina Berk. & Br. but no conclusive proof has
been adduced.

S. libertiana Fcl.*?

Sclerotia from a few millimeters up to 3 cm. in length, black;
apothecia scattered, pale, 4-8 mm. or more broad, stem slender;
asci cylindric, 130-135 x 8-10 y, apically
very slightly bluish; spores ellipsoid,
usually minutely guttulate, 9-13 x
4-6.5 uw; paraphyses clavate.

This fungus affects numerous hosts...
Among the most important on which it
causes serious disease are lettuce,** 5 8” As
ginseng,®® cucumber,” carrot, potato, Fic. 96.—S. libertiana.
parsley, hemp, rape, various bulbs, zinnia, year a FT
petunia, etc. The white mycelium is
found superficially and within the host, especially at places
where moisture is retained, as between leaves, at leaf axils, etc.,
also within plant cavities. Microscopicalky it consists of long
cells branching in a rather characteristic way, Fig. 97. Within

142 THE FUNGI WHICH CAUSE PLANT DISEASE

the host’s tissue the hyphal threads are thicker, richer in proto-
plasm, more septate, and much more branched and crooked
than outside of the host. Aérial hyphal filaments when they
touch a solid repeatedly branch in close compact fashion form-
ing the attachment organs.

At the exhaustion of the food supply and the consequent term-
ination of the vegetative period the mycelium becomes very dense
in spots and within these clumps of mycelium the sclerotium
forms; at first white, later pink, finally smooth and black (Fig. 95).
They are often found in the leaf axils (lettuce), in the pith of
stems (carrot), ete. Under
some conditions, as on uD-
suitable nutrient media,
gonidia are produced.

The sclerotia can ger-
minate at once or remain
dormant for one, perhaps

7 ane eee ene sever years, On eee
mination they send forth
from 1 to 35** negatively geotropic sprouts which grow to the
soil surface unless that be more than about 5 cm. distant. On
reaching the light the apex of the sprout begins to thicken and
soon develops its apothecium; at first inverted-
conidial, soon flat, and finally somewhat revo-
lute. Changes in atmospheric humidity cause
the discharge of ascospores in white clouds.

The ascospores germinate readily but the re-
sulting mycelium is of such small vigor that it
is incapable of parasitism. If the ascospore
germinates where it can maintain a saprophytic
life until a vigorous mycelium is developed then parcplyece, Aikee
the mycelium may become parasitic. Stevens and Hall.

Both ascospores and mycelium are comparatively short-lived.
The mycelium can migrate but a short distance over soil. No
form of conidia. except the apparently functionless gonidia. is
produced. The fuiigus may be cultivated easily upon almost any
medium, corn-meal-agar is especially suitable.

It has been repeatedly\claimed that this fungus possesses a

THE FUNGI WHICH CAUSE PLANT DISEASE 143

Botrytis conidial stage but the results of much careful work deny

this.3+ 4°

Recent tests by Westerdijk ® indicate the absence of such

biologic specialization in regard to hosts as
is found in the Erysiphe and elsewhere.

S. nicotiane Oud. & Kon.*" * parasitizes
the leaves and stems of tobacco. It is
possibly identical with S. libertiana.

S. trifoliorum Erik.1-*°

In general this resembles 8. libertiana
with which it is by some regarded as iden-
tical; sufficient evidence has, however, not
been adduced to prove them the same.
The sclerotia, varying in size from that of
a mustard seed to a pea, are found in the de-
cayed tissue, or as larger flat surface sclero-
tia. No conidia except
the functionless gonidia.
Unknown on clover.

S. bulborum (Wak.)
Rehm“ which is very
similar to 8. trifoliorum

Fic. 100.—C. xrug-
inosum. J. ascus; vated anemones.

Fic. 99.—Cultures of scle-
rotinia from tobacco on
potato agar, showing
sclerotia. After Clinton.

and without known conidia grows on hyacinth,
crocus, scilla and tulip. Cross infections be-
tween hyacinth and clover have not, however,
been successful and the species may be dis-
tinct. A sterile form, Sclerotium tuliparum,
found on the tulip may also belong here.

S. tuberosa Fcl. is found on wild and culti-

K, ascospores: 1, Several other species of the genus, among

conidia. After

Rehm and Bre- them S. alni Maul, S. betule Wor., S. aticupa-
rie Ludw, S. crategi Magn., are found on

Ericacer, Betulacez, Rosacee, Graminee, ete., but they are not
of sufficient economic importance to warrant further notice

feld.

here.

144 THE FUNGI WHICH CAUSE PLANT DISEASE

Chlorosplenium Fries (p. 135)

Ascoma mostly aggregated, small, stalked, smooth without,
green; asci cylindric, 8-spored; spores elongate, 1-celled, guttulate,
hyaline; paraphyses linear.

The genus consists of some ten species only one of which is of
interest here.

C. zruginosum (Oed.) d Not.

The apothecia and mycelium are verdigris-green as is also the

A +7 B
Fic. 101.—D. wilkomii. A, natural size and single apothe-
cium enlarged; B, an ascus. After Lindau.
wood penetrated by it. The fungus appears to be mainly sapro-
phytic but may be partially parasitic. Fig. 100.

Dasyscypha Fries (p. 135)

This is 2 genus of some one hundred fifty species, mostly sapro-
phytic but sometimes parasitic on twigs. The apothecia are small,
short-stalked or sessile, waxy or membranous, bright colored in the
disk, with mostly simple hairs on the outside and margin. Asci
cylindrical or clavate, &spored; spores ellipsoid or fusiform,
hyaline, 1-celted, rarely 2-celled, sometimes guttulate; paraphyses
blunt, needle-like.

THE FUNGI WHICH CAUSE PLANT DISEASE 145

D. willkommii Hart.” causes a serious European larch disease
and affects also the pine and fir.

The stromata appear as yellowish-white pustules on the bark
soon after its death. Here hyaline conidia are produced on the
open surface or in cavities. Apothecia 2-5 mm. broad appear
later. The ascospores can infect wounds: the conidia seem to be
functionless. The myce-
lium spreads through the.
sieve tubes, intercellular
spaces, and xylem to the
pith.

Apothecia short-stalked,
yellowish without, orange
within; asci 120 x 9 4g;
spores 18-25 x 5-6 uy;
paraphyses longer than
the ascus.

D. resinaria Rehm * is

a wound parasite much VG

i in i Fic. 102.—Lachnella. F, habit sketch; G, ascus
like the above in its ef. ey a Ae oe,

fects. It occurs chiefly on
spruce and larch but sometimes also on pine, both in Europe
and America.

Ascophores upon cankers on branches and trunk of the host,
very similar to those of the preceding species but with more evident
stipe and paler disk; spores very minute, subglobose, 3 x 2-2.5 y;
conidia 2x 1 yp.

D. calyciformis (d Wild.) Rehm occurs on several conifers;
D. subtilissima (Sacc.) on fir and larch; D. abietis Sacc. on Picea.

Lachnella Fries (p. 135)

This is similar to the last genus but with the apothecia usually
sessile and the spores usually 2-celled at maturity, and in two
rows in the ascus. There are about forty species.

L. pini Brun.” injures pine twigs. The apothecia are brown
outside; the disc reddish-yellow with a white margin.

Ascoma short-stipitate, 5 mm. in diameter, pale brown; disk light

146 THE FUNGI WHICH CAUSE PLANT DISEASE

orange-red with a pale margin; asci 109 x 8-9.5 ; spores 19-20 x
6.5-8.5 yw, hyaline.

Hymenoscypha Fries (p. 136)

This genus of over two hundred species is mainly saprophytic,
one species only in its conidial stage being parasitic.

Ascoma sessile or short-stipitate, usually
smooth; asci cylindric to globoid, 8-spored;
spores elliptic, blunt to pointed, hyaline;
paraphyses filamentose, apically enlarged,
hyaline.

H. tumulenta P. & D.” in its conidial
stage as Endoconidium, affects rye grain
causing it to shrivel and assume poisonous
properties. The conidia are borne en-
dogenously in the terminal branches of the
hyphe and escape through an opening in
the end of the branch.

Mollisiacez (p. 134)

Bins x ‘ SF
Fic. 103.—Hymenoscy-

pha. J, habit sketch;
K, ascusand paraphy- | Ascocarp free from the first or sunken in

ses. After Rehm. = the substratum and later erumpent, at first

more or less globose, becoming flattened; asci 8-spored, opening
by a slit; spores hyaline, 1 to many-celled; paraphyses slender.
Above four hundred species.

Key To GENERA OF Mollisiacee

Ascocarp fleshy, waxy, rarely membranous. I. Mollisiese.
Ascocarps not sunken in the substratum
Ascocarps on a visible, often radiate
mycelium
Spores elongate, often fusiform,
Lecelled seat tause Sone shares 1. Tapesia.
Spores filiform, many-celled........ 2. Trichobelonium.
Ascocarps not seated on a visible my-
celium
Spores 1-celled
Spores spherical. ............... 3. Mollisiella.
Spores elongate. ................ 4. Mollisia.

THE FUNGI WHICH CAUSE PLANT DISEASE 147

Spores becoming 2-celled.......... 5. Niptera.
Spores elongate filiform, 4-celled.... 6. Belonidium.
Spores filiform many-celled........ 7. Belonopsis.

Ascocarps at first sunken in the substra-
tum, later erumpent
Ascocarps bright colored, only slightly

erumpent,
Spores ellispoid or elongate, rounded,
l-celled. ........0..0.00.0.0000. 8. Pseudopeziza, p. 147.
Spores becoming many-celled....... 9. Fabra, p. 149.

Ascocarps dark colored, at length
strongly erumpent
Spores ellipsoid or fusiform, 1-celled

the margin................. 10. Pirottea.
Ascocarps externally smooth, the
margin at most merely shred-
Med ia iat etude sel edld sangre eds 11. Pyrenopeziza.
Spores many-celled by transverse
SEPUAS ot yicwas meee ae ees 12. Beloniella.
Ascocarps gelatinous gristly, horny when
OY sain act NE SaaS lo dyo andes ade II. Calloriez.

Of this large number of genera only two are important patho-
gens, several of the others are parasitic on non-economic hosts
while others are saprophytic chiefly on decaying woody parts.

Pseudopeziza Fuckel

The genus comprises some ten species, all parasitic on leaves,
several of them upon economic plants causing serious disease.
The very small apothecium develops subepidermally breaking
through only at maturity, light colored; spores 1-celled, hyaline,
in two ranks in the ascus; paraphyses somewhat stout, hyaline.
Conidial forms are found in Gleeosporium, Colletotrichum and
Marssonia.

P. medicaginis (Lib.) Sacc.* *?

The epiphyllous apothecia are in the older leaf spots, subepider-
mal at first but eventually breaking through.

Apothecia saucer-shaped, light colored, fleshy; asci clavate;

148 THE FUNGI WHICH CAUSE PLANT DISEASE

spores hyaline, 10-14 » long; paraphyses numerous, filiform. A
Phyllosticta thought to be its conidial stage has been reported.*?
On dead spots in leaves of alfalfa and black medick.
P. trifolii (Bernh.) Fcl.
This is closely related to, perhaps identical with, the last species.
Sporonema (Spheronzema) phacidioides Desm. is supposed to be
its conidial form. This co-
nidial stage has not however,
9 been observed on alfalfa.
ws —) Ascocarps mostly epiphyl-
lous, on dead spots, averaging
0.5 mm. broad, yellowish or
brownish; spores elliptic 10-

Fic. 104.—P, trifolii. Ascus and paraph-
yses; germinating spores. After Ches- 14x 5-6 H.

ter.

Conidia in cup-shaped pyc-
nidia which are numerous, small, light brown; disk cinnamon-
colored; conidia ovoid-oblong, 5 u, bi-guttulate.

P. tracheiphila Miiller-Thurgau *4 is found upon the grape in
Europe.

P. salicis (Tul.) Pot. occurs on Salix. Conidia ( =Glceosporium
salicis).

P, ribis, Kleb.5*57

Apothecia appear in the spring on dead leaves of the previous
season ; saucer-shaped, fleshy, somewhat
stalked; asci clavate, spores hyaline,
ovoid; paraphyses simple or branched,
slightly clavate, rarely septate.

Conidial phase (=Glceosporium ribis)
on the leaves of the host forming an
abundant amphigenous infection; acer- :
vuli stromatic; conidiospores commonly Re:
19 x 7 », varying from 12-24 x 5-9 u, Fig, 105—P. ribis. Apothe-
escaping in gelatinous masses. cium in section, After Kle-

: bahn.

On red and white currants less com-
monly on black currants and gooseberries both in Europe and
America.

The ascigerous stage of this fungus was demonstrated by
Klebahn * in 1906 to be genetically connected with what had been

THE FUNGI WHICH CAUSE PLANT DISEASE 149

earlier known as Gloeosporium ribis (Lib.) Mont. & Desm. Old
leaves bearing the latter fungus were wintered out-doors in filter
paper and in the spring were found with this ascigerous stage.
The ascospores were isolated, grown in pure culture and typical
conidia were produced. The ascospores also infected the host
leaves successfully producing there the typical Gloeosporium.
The conidial stage is the only one ordinarily seen. The acervuli
are subepidermal elevating the epidermis to form a pustule which
eventually ruptures and allows the spores to escape as a gelatinous
whitish or flesh-colored mass. The spores are curved and usually
larger at one end than at the other.

Fabraea Saccardo (p. 147)

This is a genus of some ten species of small leaf parasites
which much resemble Pseudopeziza but differ from it in its 2 to
4-celled spores.

F. maculata (Lev.) Atk.”

The perfect stage is common on pear and quince leaves which
have wintered naturally. When such leaves are wet the white
8-spored asci may be seen
crowding through the surface
in small elliptical areas. The
apothecium is paraphysate; the
spores hyaline and 2-celled.

Conidial form (=Entomo-
sporium maculatum) on leaves
and fruits; acervuli, black,
subepidermal, the epidermis Nh
breaking away to expose the Fre. 106.—F. maculata. 1, acervulus of
spore mass; spores hyaline pring vere P gidiaa 3, spores.
18-20 x 12 p, 4-cells in a
cluster, the lateral cells smaller, depressed; stipe filiform 20 x
0.75 u; the other cells with long sete.

Atkinson ® proved the connection of the ascigerous with the
conidial form by cultivating the conidia from the ascospores. The
conidial form is very common and destructive on pear and quince
leaves and fruit. The mycelium which abounds in the diseased
spot is hyaline when young, dark when old. It collects to form a

150 THE FUNGI WHICH CAUSE PLANT DISEASE

thin subcuticular stroma. On this the spores are produced on
short erect conidiophores, Fig. 106; eventually the cuticle ruptures
and the spores are shed. The spores germinate by a tube which
arises from near the base of a bristle.

F. mespili (Sor.) Atk. on medlar with the conidial form Entomo-
sporium mespili (D. C.) Sacc. is perhaps identical with the above.
There are only minor and uncertain differences in the conidial
stage. Sorauer by inoculation with conidiospores produced on
pear typical spots which bore mature pustules after an interval of
about a month. He referred the fungus to the genus, Stigmatea
Fries. See p. 243.

Cenangiacee (p. 134)

Ascoma at first buried, later erumpent, on a stroma, dark, with a
rounded or elongate disk; asci 8-spored; spores long or filiform, 1 to
many-celled, often muriform, hyaline or dark; paraphyses branched
forming a complete epithecium. About two hundred fifty species.

Key To SuBFraMILIEs AND GENERA oF Cenangiacee

Ascocarps coriaceous, corneous or waxy
when fresh.............200eeee eee I. Dermatez.
Ascocarps without a stroma, at first im-
mersed.
Spores 1-celled
Ascocarps externally bright colored,

GOWN Ys 2-5 Ses se Hee asi sae ee 1. Velutaria.
Ascocarps externally dark
Ascocarps smooth; spores hyaline. 2. Cenangium, p. 151.
Ascocarps downy; spores colored.. 3. Schweinitzia.
Spores 2 to 4-celled, elongate
Spores hyaline
Spores always 2-celled; ascocarp
smooth. ................... 4. Cenangella.
Spores 2 to 4-celled; ascocarps
downy externally........... 5. Crumenula.

Spores at length brown or black
Disk elongate with a thick rim... 6. Tryblidiella.
Disk rounded
Rim thin; spores 2-celled...... 7. Pseudotryblidium.
Rim involute; spores 4-celled.. 8. Rhytidopeziza.

THE FUNGI WHICH CAUSE PLANT DISEASE 151

Spores many-celled, filiform ......... 9. Gordonia.
Ascocarps springing from a more or less
developed stroma

Spores 8, not sprouting in the ascus... 10. Dermatea, p. 152.
Spores sprouting in the asci which be-
come filled with conidia......... 11. Tympanis.
Ascocarps gelatinous when fresh.......... II. Bulgariex.

Ascocarps sessile or stalked, with smooth,
saucer-shaped disc
Spores 1-celled, round............... 12. Pulparia.
Spores 1-celled, elongate
Ascocarps soft, gelatinous inside, ses-

sile, thin. .................... 13. Bulgariella.
Ascocarps soft, gelatinous, stalked,
bICk oc Bony sac get's Mereaiete: 14. Bulgaria, p. 152.
Ascocarps watery gelatinous... .... 15. Sarcosoma.
Spores 2-celled
Spores unequally 2-celled rounded
at the ends... ............... 16. Paryphedria.
Spores elongate, acute at the ends.. 17. Sorokina.
Spores filiform .................000. 18. Holwaya.
Spores muriform. ................... 19. Sarcomyces.
Ascocarps with convolute tremelliform
dises
Spores 1-celled, hyaline. ............. 20. Hematomyces.
Spores muriform, blackish........... 21. Hematomyxa.

With few exceptions these genera are so far as known sapro-
phytes though it is probable that further study will reveal some of
them as weak parasites or possibly as destructive ones.

Cenangium Fries (p. 150)

Parasitic or saprophytic chiefly in bark, the apothecium de-
veloping subepidermally and later breaking through to the surface;
sessile, light colored without, dark within; asci cylindric-globoid,
8-spored; spores ellipsoid, 1 or rarely 2-celled, hyaline or brown, in
one row; paraphyses colored. About seventy species.

C. abietis (Pers.) Rehm. has caused serious epidemics upon
pine in Europe and America.

Ascoma dark-brown, erumpent, clustered; spores ellipsoid,
10-12 x 5-7 pu.

152 THE FUNGI WHICH CAUSE PLANT DISEASE

Conidia (=Brunchorstia
destuens Erikss.) in pyc-
nidia which are partially
embedded in the _ host,
the smaller simple, the
larger compound, 1-2 mm.
in diam.; spores 30-40 x
3 p, tapering-rounded at
SCRA Erg ea 2! yf each end, 2 to 5-septate.
Fic. 107.—Cenangium, habit sketch, asci and A second conidial phase

DRAPE ees re age (=Dothichiza ferruginosa

Sacc.) has simple spores.
C. vitesia occurs in conidial form as Fuckelia on Ribes.

Dermatea Fries (p. 151)

A genus of over sixty species some of them parasitic. In many
species conidia in pycnidia are known.

Ascocarps scattered or clustered, stromate, sessile or not,
black or brown; asci small, thick-
walled, 8 or 4-spored; spores el-
lipsoid or spindleform, 1-celled,
becoming 4 to 6-celled, brown,
2-ranked; paraphyses septate, api-
cally enlarged and colored.

D. carpinea (Pers.) Rehm. is
a wound parasite on the horn-
beam and beech; D. cinnamomea
(Pers.) Rehm. on oaks; D. acerina
Karst, on maple (Acer pseudo- ;
platanus); all in Europe. BAe. asue en Cee cl

D. prunastri (Pers.) Fr., with After Tulasne and Rehm.
its conidial form Sphzeronema spurium Fr. is found on Bark of
various species of Prunus, in Europe and America.

Bulgaria Fries (p. 151)
The gelatinous apothecium is rather large and dark colored;
asci 4 to 8-spored; spores 1-celled, elongate, brown.
There is one species worthy of mention.

THE FUNGI WHICH CAUSE PLANT DISEASE 153

B. polymorpha (Oed.) Wett.®* © is a common saprophyte on
bark. It is said to sometimes become parasitic. Ascocarps black,
stipitate; disk scarcely cupped, ranging up to 4 cm. in diameter
although usually smaller.

Caliciacee (p. 134)

Stroma more or less thalloid, with or
without algal cells, often rudimentary and
inconspicuous; ascoma more or less globoid,
stipitate; the apex of the ascus dissolv-
ing before the spores are matured, thus
allowing the hyaline unripened spores to es-
cape and mature afterwards.

This small family (less than one hun-
dred twenty-five species) contains the only
lichens of phytopathological importance, un-
less the foliose lichens which sometimes ap- Fic. 109.—C. pallida

‘ on Grape Root.
pear on poorly kept fruit trees be consid- 2, Ascus, After
ered. Massee.

Key To THE GENERA OF Caliciacee

Ascoma with a long stalk
Spores spherical, or subspherical
Spores colorless or only slightly colored. 1. Coniocybe, p. 153.
Spores brown or brownish. .......... 2. Cheenotheca.
Spores elongated, septate
Spores elongate elliptic or egg-shaped,

usually two-celled............... 3. Calicium.
Spores elliptic to spindle-form, 4 to
S-celleds cise seeds gevweawic we cme 4, Stenocybe.
Ascoma short stalked
Spores 2-celled. ..........--.-20 ee ees 5. Acolium.
Spores globose, I-celled..............-- 6. Sphinetrina.

Coniocybe pallida (Pers.) Fr. is generally distributed through-
out Europe and America, commonly on the bark of various forest
trees and upon the crown and roots of the grape. The parasitic

154 THE FUNGI WHICH CAUSE PLANT DISEASE

nature of the fungus is in doubt.” The entire height of the as-
cocarp is 2 mm.; head white, then grayish brown; asci cylindric,
8-spored; spore tinged with brown, 4-5 » in diameter. The species
as a, pathogen is usually referred to as Reesleria hypogaea Thiim
& Pass. and given a place in the Geoglossacee; but Durand ® fol-
lows Schroter in excluding the species from that family. Fig. 109.

Phacidiales (p. 124)

This order, comprising some six hundred species only a few of
which are pathogens, is characterized as follows: mycelium well
developed, much branched, multiseptate; ascocarps fleshy or
leathery, free or sunken in the substratum or in a stroma,
rounded or stellate, for a long time enclosed in a tough cover-
ing which at maturity becomes torn; paraphyses usually longer
than the asci, much branched, forming an epithecium.

Key ro Fami.iss or Phacidiales

Ascocarps soft, fleshy, bright colored... ... 1. Stictidacer, p. 154.
Ascocarps leathery or carbonous, always ‘
black
Ascocarps at first sunken, later strongly
erumpent, hypothecium thick. ..... 2. Tryblidiacer, p. 155.
Ascocarps remaining sunken in the sub-
stratum, hypothecium thin, poorly
developed..................00002 3. Phacidiacer, p. 155.

Stictidacez

The members of this family (about twenty genera and two
hundred fifty species) are usually considered saprophytes, al-
though one species of Stictis has recently been described as a
parasite.

Stictis Persoon

Perithecia sunken, pilose, at length erumpent; asci cylindric,
containing eight filiform, multiseptate spores; paraphyses filiform,

THE FUNGI WHICH CAUSE PLANT DISEASE 155

richly branched apically. Of the seventy Vp
or more species of the genus only one, Hl
S. panizzei d Not., originally described
from fallen olive leaves in Italy, has been
charged with producing disease. It has
within the last few years become very de-
structive in Italy.

The Tryblidiacez, with six genera and
some seventy species, are likewise chiefly
saprophytes with the possible exception of
the two genera Heterospheria and Sclero-
derris."* The former occurs on umbellifers
while the latter may contain the perfect
stage of certain currant and gooseberry
fungi (Mastomyces and Fuckelia) of Europe
as well as a European parasite of the wil-
low. (i

} O

er Fie. 110.—Stictis. D,
Phacidiacez (p. 154) habit sketch, E, ascus
and paraphyses. Af-

Apothecia sunken, more or less erumpent, hen onan
disk-like or elongate, single or grouped, leathery or carbonous,

black, firm, opening by lobes or rifts.

Key to GENERA OF Phacidiacee

Apothecia not inseparably united to the sub-

SUYAtUMs5 oe ache aaa sete! scones I. Pseudophacidiee.
Spores elongate, hyaline, l-celled....... 1. Pseudophacidium.
Spores elongate, spindle-form or filiform,

multicellular.
Spores elongate to filiform, not muri-
form
Apothecia rounded, opening by a
rounded mouth
Spores elongate or spindle-form
paraphyses, none. .......... 2. Dothiora, p. 156.
Spores elongate-globoid, 2-celled;
paraphyses present........... 3. Rhagadolobium.

156 THE FUNGI WHICH CAUSE PLANT DISEASE
Spores needle-like; paraphyses
Presents cnc cea gees wnrdewes 4. Coccophacidium.
Apothecia elongate; opening by a
Slits vahave wares mers ual a suntcaeters 5. Clithris, p. 157.
Spores elongate, muriform, with pa-
TAPHYSES: 0.62 ces eee eee eee 6. Pseudographis.
Apothecia firmly united to the substratum. II. Phacidiex.

Apothecia separate, no stroma
Spores ellipsoid or globoid, 1 to 4-celled
Spores 1-celled
Apothecia rounded
Paraphyses not forming an epi-

thecium. ................ 7.

Paraphyses forming an epithe-

CIUM sss ako asda Seieens 8.
Apothecia irregular, elongate, .
opening by an_ irregular
MOU ei oiocice siaieiesdinie muosee cece 9
Spores 2 to 4celled
Spores hyaline
Apothecia rounded, spores 2 to
4-celled..............000. 10
Apothecia elongate, spores
" Qeelled........... Becton 11
Spores brown... ............... 12
Spores filiform or needle-like, 1 to
many-celled.................00. 13
Apothecia collected on a stroma, opening
elongate
Spores 1-celled, hyaline
Spores ovate. .............000008e 14.
Spores filiform or needle-like. ...... 15.
Spores 2-celled
Spores hyaline.................... 16
Spores brown... ................. 17

Phacidium, p. 157.

Trochila, p. 157.

. Cryptomyces, p. 158.

. Spheropeziza.

. Schizothyrium.
. Keithia.

. Coccomyces.

Pseudorhytisma.
Rhytisma, p. 158.

. Marchalia.
. Cocconia.

Dothiora Fries (p. 155)

There are about ten wood-inhabiting species.

Ascocarp at first

sunken in the substratum, later irregularly erumpent; disk black;
asci clavate, 8-spored; spores elongate or spindle-form, many-

THE FUNGI WHICH CAUSE PLANT DISEASE 157

celled or muriform, hyaline or slightly yellowish ; paraphyses
wanting.
D. virgultorum Fr. grows on birch.

Clithris Fries (p. 156)

A small genus of about twenty species found
on wood and bark; mainly saprophytes. 4

Ascoma sunken, then erumpent, elongate,
with lip-like margins, dark colored; asci clavate,
8-spored, often blunt pointed; spores linear or
spindle-shaped, multicellular; paraphyses fili-
form, coiled apically, hyaline.

C. quercina (Pers.). Rehm. is found on oak
branches and is perhaps identical with C. aureus
Mass. on willows. C. juniperus is found on liv-
ing juniper.

Phacidium Fries (p.- 156)

Over seventy species chiefly on leaves or od

herbaceous stems. Ascoma single, flattened, Fie. 111.—Clithris.

5 é j Ascus with spores
soon becoming lenticular, breaking open by and_paraphyses.
an irregular rift; asci clavate, 8-spored; spores “fer Rehm.
ovate or spindle-shaped, hyaline, 1-celled; paraphyses thread-like,
hyaline. Conidial form probably in part =Phyllachora.

P, infestans Karst. is a parasite on pine leaves.

Trochila Fries (p. 156)

Perithecia sunken and closed, later erumpent, black, leathery;
asci clavate 8-spored; spores long, hyaline, 1-celled; paraphyses
filamentose forming an epithelium. Fig. 112.

T. popularum Desm. is thought by Potebnia ™’ and Ed-
gerton 2” to be the ascigerous form of Marssonia castagnei
D. & M.

T. craterium is the ascigerous form of Glceosporium para-
doxum. See p. 541.

158 THE FUNGI WHICH CAUSE PLANT. DISEASE

Cryptomyces Greville (p. 156)

A genus of some ten species living on wood or leaves, forming
large black blotches.

Ascoma sunken in the substratum, flattened, erumpent, irregu-
lar in outline, coal black; asci clavate, 8-spored; spores elongate,
1-celled, paraphyses filiform.

C. maximus (Fr.) Rehm ”® is a parasite on willow and dogwood
twigs in Europe and America, forming large carbonous areas
under the bark.

Rhytisma Fries (p. 156)

To Rhytisma belong about twenty-five species which cause very
conspicuous, though but slightly injurious, black leaf-spots. The
spots which are white within, are due to sclerotial
cushions formed in the host tissue. Thickening
of the leaf occurs in the infected part. One-
celled conidia (Melasmia form) are abundantly
produced in pycnidia early in the season, followed
by sclerotium formation. Much later, usually well
into winter or the following spring, the apothecia
appear. Besides the asco-spore-producing forms
several species of which the asco-spores are un-

hila.
ee pois known have been referred here.

ses. After
Rehm.

Ascoma on a sclerotial stromatic layer, which

is black above, white within; ascocarps elongate,
opening by a lip-like slit; asci clavate, often blunt pointed,
8-spored; spores filiform or needlelike, hyaline, mostly 1-celled,
lying parallel and lengthwise of the ascus; paraphyses filiform,
hyaline, often arched above.

R. acerinum (Pers.) Fr.

The spot is at first yellow and thickened and in this stage bears
numerous conidia upon short conidiophores. The apothecia
ripen in spring and rupture by numerous irregular fissures which
follow the ridges of the wrinkled surface. Klebahn secured infec-
tion by ascospores resulting in three weeks in yellow spots and in
eight weeks in conidiospores. The conidia are supposed to aid in

THE FUNGI WHICH CAUSE PLANT DISEASE 159

spreading the fungus during the summer though they have not
yet actually been observed to germinate or to cause infection.

Apothecia radiately arranged on the stroma which is about
0.5-1.5 cm. across; asci
120-1380 x 9-10 yu; spores
large, 65-80 x 1.5-3 4p;
paraphyses numerous, in-
curved or hooked.

Conidia (=Melasmia
acerina Lev.) preceding
the asci, producing numerous
small, hyaline, 1-celled
spores in an extended hy-
menial layer.

On various species of Fic. 113.—R. acerinum. F, conidial layer;
mapl e, appar ently consist- £, ascus and paraphyses. After Tulasne.
ing of races since in different localities the host differs without a
crossing over of the fungus.

R. punctatum (Pers.) Fr. also occurs on maple, especially Acer
pseudoplantanus. It may be distinguished from the preceding by
its small, speck-like stromata.

R. salicinum (Pers.) Fr. is found on willow in Europe and
America. It is quite similar in external appearance to R. acerina
except for the smaller average size of the spots.

R. symmetricum Mill. is another willow inhabiting species.
The apothecia are amphigenous and are said to mature in autumn
on the still live leaves.

Other species are common especially on various Ericacez and
Coniferee in Europe and America.

Hysteriales (p. 124)

Small species with elongated, black, covered apothecia which
open by a long narrow slit exposing the hymenium; asci 8-spored;
spores usually long and slender. Some few are leaf parasites but
most are wood saprophytes. Pycnidia are found in some species.
The order serves as a bridge between the Discomycetes and the
Pyrenomycetes. About four hundred species.

160 THE FUNGI WHICH CAUSE PLANT DISEASE

Key to Famittes or Hysteriales

Ascocarps immersed; walls of the ascocarps
connate with the membranous cover-
ING: daGealeciaed ste. eae ee eat elees 1. Hypodermatacee, p. 160.
Ascocarps at first immersed, erumpent,
walls free
Walls membranous or coriaceous, black. 2. Dichenacee, p. 162.
Walls thick, almost corky, gray or
NACH eis crass or exe Sachin Sie damarieae aad 3. Ostropacee.
Ascocarps from the first free
Walls carbonous, black; shield-shaped,
round, oval or more commonly

Vin Ar 6 06 a wie os anee Se Oe 4. Hysteriaceer, p. 163.
Walls membranous or horny, brown,
ascocarps vertical, clavate......... 5. Acrospermaceez.

The third and fifth families contain no pathogens.

Hypodermatacee

Ascocarp flattened, rounded or elongate, rarely branched,
united to the substratum; opening by a slit; asci 4 to 8-spored;
paraphyses apically branched, the branches forming an epi-

thecium, or hooked or crimped. About fifty species, chiefly
saprophytes.

Key to GENERA oF Hypodermatacese

Spores elongate, rather broad
Spores 1-celled or by cross walls 2 to
many-celled
Spores 1-celled
Asci 8-spored, spores spindle-form
Spores hyaline................... 1. Henriquesia.
Spores brown... ............... 2. Farlowiella.
Asci 4-spored, spores hyaline....... 3. Hypodermella, p. 161.
Spores 2-celled, hyaline
Apothecium black................ 4. Hypoderma, p. 161.
Apothecium red. ................. 5. Angelinia.

THE FUNGI WHICH CAUSE PLANT DISEASE 161

Spores 4 to many-celled, spindle-form

Spores 4-celled, mostly hyaline. ... 6. Gloniella.
Spores 4 to many-celled, brown..... 7. Rhytidhysterium.
Spores muriform, hyaline. ............. 8. Hysteropsis, p. 161.
Spores filiform, 1-celled.................. 9. Lophodermium, p. 161.

Of these genera only four are important here.

Hypodermella Tubeuf (p. 160)

This differs from the next genus in its pyriform unicellular
spores; asci 4-spored. Two species, both European and economic.

H. larius Tub. affects larch needles in Europe. ©

H. sulcigena Link is on pine needles.

Hypoderma De Candolle (p. 160)

Apothecia oblong, opening through a thin black cover by a
long fissure; asci 8-spored; spores cylindrical or fusiform, 2-celled
at maturity; paraphyses hooked at the end.

H. desmazieri Duby," on pine needles in America and Eu-
rope.

Amphigenous; asci broadly clavate, sessile; spores hyaline,
linear-elliptic, obtuse and 2-rowed.

H. laricis, H. strobicola, H. pinicola, produce premature leaf
fall in various conifers.

Hysteropsis Rehm

Asci clavate, 8-spored; spores hyaline, muriform; paraphyses
branched, forming an epithecium.
H. brasiliensis occurs on cacao trees.

Lophodermium Chevall

Spores long, thread-like, continuous; conidiospores in pycnidia.

L. pinastri (Schr.) Chev. occurs in Europe ™ and America on
Pinus sylvestris especially on young plants causing the leaves to
fall. The first year pycnidia only are formed, the asci not ap-
_pearing until the second year.”

162 THE FUNGI WHICH CAUSE PLANT DISEASE

Ascocarps scattered on the leaf, shining black, up to 1 mm.
long; asci clavate, 8-spored; spores nearly as long as the ascus,
90-120 x 1.5y. Conidia cylindric, hyaline,
continuous, 6-8 x 1 yu.

L. brachysporum Rost.

Perithecia epiphyllous; asci cylindric, short-
stalked, apex rounded, 120 x 20-25 pn, 8-
spored; paraphyses bacillar, apex curved;
spores oblong, 1-rowed, hyaline, 28-30 x
9-10 p.

It is common on pine leaves.”

Several other species are parasitic upon
various conifers, among them: L. macrospo-
rium (Hart.) Rehm, on spruce leaves, in
Europe and America; L. nervisequum (D. C.)
Rehm, on fir leaves, a very destructive
eee European species; the pycnidial stage is

H, habit sketch; J, Septoria pini Fuckel; L. juniperinum (Fr.)

seeus. oe pales Not, on. juniper leaves and twigs in

Europe and America; L. gilvum Rost., on

pines; L. abietis Rost., on spruce leaves; L. laricinum Duby, on
larch. The last four species are European.

Dichenacee (p. 160)

This family contains the single genus Dichena.

Dichena Fries

Apothecia grouped in rounded spots; at
first sunken, then erumpent, rounded or elon-
gate, dark brown; asci irregularly pyriform, 4 ..
to 8-spored; spores ellipsoidal, at first 1-celled, P5Sxy
at maturity multicellular; paraphyses filiform. yg. 115—Hysterium
Some seven species are found upon various ™acrosporum. Af-
trees. Se

D. quercina Fr. causes rough black patches on bark of young

oaks in Europe and America; D. faginea Fr., a similar effect on
beech.

THE FUNGI WHICH CAUSE PLANT DISEASE 163

Hysteriacee (p. 160)

Ascocarps free, seated upon the substratum,
elongate or linear, straight, curved or even
branched, disk-form, boat-shaped or band-like,
black; asci usually 8-spored; paraphyses fila-
mentous, often forming an epithecium.

About fourteen genera and some two \
hundred fifty species, many but poorly 22
known. Several genera contain plant patho- Fis. 116.—D. quer-

ae cina. Ascus and
gens, but they are not often of economic im- paraphyses. After

portance. elm,
Key to Genera or Hysteriaceze
Ascoma linear, flattened, broadly sessile
Spores ellipsoid or spindle-shaped, many-
celled
Spores 1-celled, 16 in each ascus..... 1. Cyclostomella.

Spores 2-celled, sometimes 4-celled,
ellipsoid or elongate
Spores hyaline
Asci 8-spored, spores 2 to 4-celled
Paraphyses scarcely branched. 2. Aulographum.
Paraphyses forming an epithe-
ClUMtigs.cseeeawet cee toes 6 3. Glonium.
Asci many-spored, spores 2-celled. 4. Hariotia.
Spores colored, 2-celled; leaf infect-
ing fungi
Paraphyses present
Ascoma seated on a cottony

StTOMAY o3e 4s ba nieeeeee = 5. Lembosia.
Ascoma radial, on a circular
stroma
Spores 2-celled, 8 in each
ASCUSs is he eee nego us Fa 6. Parmularia.
Paraphyses absent, stroma irreg-
ularly circular. ..........--- 7. Hysterostomella.
Spores 4 to 8-celled, elongate or spindle-

form 3
Spores hyaline, spindle-form, 4
Celled.. ccc sates y 8. Hysteroglonium.

164 THE FUNGI WHICH CAUSE PLANT DISEASE

Spores brown, elongate, 4 to
S-celled. ........--.5----- 9. Hysterium.
Spores elongate, muriform. ........ 10. Hysterographium, p. 164.
Ascoma boat or band-shaped, not sessile
Spores spindle-formed, brown, many-
celled
Spores 4 to 8-celled; asci 8-spored. 11. Mytilidium.
Spores many-celled; asci 4-spored. 12. Ostreion.
Spores filamentose, hyaline or yellow 13. Lophium.
Ascoma stellate..........--2-..0-000- 14. Actidium.

Hysterographium Corda

Asci clavate, 8-spored; spores muriform, dark colored when
mature; paraphyses branched forming an epithecium. About
seventy species.

H. fraxini (Pers.) de Not. occurs on Oleacez, particularly on

Fig. 117.—H.

5 SE’ Se

fraxini. Ascus ae
and paraphyses. Fie. 118.—Gymnoascus, sexual organs.
After Rehm. After Dale.

the ash, perhaps only as a saprophyte. It is found both in Europe
and America.

Aspergillales (p. 124)

The Aspergillales are clearly distinguished from the other
Ascomycetes by the possession of a closed ascocarp in which the
asci are not collected in a hymenium but are irregularly scattered.
The forms with the least developed peridium are evidently related

THE FUNGI WHICH CAUSE PLANT DISEASE 165

to the Endomycetacex; the forms with a more highly developed
peridium, to the Pyrenomycetes, particularly to the Perisporiales.
Conidial forms are usually present, indeed in many cases they
preponderate almost to the entire exclusion of the ascigerous form
which may be seen only under very exceptional conditions.
Sexual reproduction has been demonstrated in several families.
In the Gymnoascacez (Dale ® and Eidam ©) there are usually two
twisted branches (Fig. 118) which conjugate. These branches
are multinucleate at the time of fusion. The ascogonium de-
velops from this fertilization much as is described on pages 116-
117. In the Aspergillacee similar sexual organs are formed but
parthenogenesis or a much reduced form of fertilization is often
met. In all, the species number two hundred fifty or more.

Key to Famiuies oF Aspergillales

Peridium made up of loose floccose hyph2. 1. Gymnoascacee.
Peridium compact, closed
Ascocarps mostly small, not subterranean
Ascocarps mostly sessile without
stroma; peridia remaining closed.. 2. Aspergillacez, p. 166.
Ascocarps mostly stalked; peridia open-
ing at maturity by lobes, or ir-
POPUALLY' < s4.c 04 Gee tte ee eo ah 3. Onygenaceee.
Ascocarps sessile, the spores issue in
columnar masses from the goblet-

shaped peridia................-- 4, Trichocomacee.
Ascocarps sessile on a small stroma... 5. Myriangiacee, p. 170.
Ascocarps mostly enlarged, tuberous, sub-
terranean.

Peridium clearly distinct from the

walls of the ascocarp; spore masses

powdery at maturity. ........... 6. Elaphomycetacee.
Peridium not clearly limited, continu-

ous with the walls of the ascocarp;

spore masses never powdery..... 7. Terfeziacez.

Of these the second and fifth families only contain pathogens.
The Gymnoascacee of five genera and some fifteen species are
found on manure, and other organic matter. The third and fourth

166 THE FUNGI WHICH CAUSE PLANT DISEASE

families are monogeneric; the third on hoofs, horn, etc.; the
sixth is subterranean and the Terfeziacez more or less subter-
ranean.

Aspergillacez (p. 165)

The ascocarp, in many forms but rarely seen, is a small spherical
or tuber-shaped body, usually indehiscent, rarely opening by a
pore: The spherical or pyriform asci bear from 2 to 8 spores which
may be from 1 to many-celled. The ascocarp is in some genera
provided with appendages which strongly resemble these of
the Erysiphacee (Microascus). Conidia are produced in great
abundance.

In Aspergillus and Penicillium fertilization is said by some
observers to be accomplished by conjugation of a straight odgo-
nium with a spirally coiled antheridium, this act resulting in an
ascogenous hypha. Recent work of Dale” (see also Fraser and
Chambers”) denies such fusion in one species of Aspergillus
which she studied, though sexual organs were often present,
and predicates a reduced form of sexuality consisting of fusion
of the nuclei of the ascogonium with each other.

Key To Genera or Aspergillacee

Spores 1-celled
Perithecium flask-shaped, beaked or papil-
TAO. ie cat.no be ame ea aaa e asaei’ 1. Microascus.
Perithecium not beaked
Perithecium with hair-like appendages;
peridium compact, mostly dark
colored
Appendages straight hairs or forming
a hairy felt.................. 2. Cephalotheca.
Appendages apically coiled hairs.... 3. Magnusia.
Perithecium unappendaged; peridium
membranous or fleshy
Conidia borne directly on the myce-
lium
Chlamydospores borne in chains.. 4. Thielavia, p. 167.
Chlamydospores borne singly..... 5. Rostrella, p. 168.

THE FUNG] WHICH CAUSE PLANT DISEASE 167

Conidia borne on distinct conidio-
phores
Conidia borne singly; conidio-
phores branching at right
angles...............00000e 6. Aphanoascus.
Conidia borne in chains
Conidiophores simple, aggre-
: gated into bundles........ 7. Emericella.
Conidiophores enlarged apically
bearing numerous sterig-

mata
Sterigmata simple. ......... 8. Aspergillus, p. 168.
Sterigmata branched........ 9. Sterigmatocystis.
Conidiophores, sympodially
branched. ............... 10. Eurotiopsis.

Conidiophores bushy branched
Conidiophores single, peri-
thecia sessile........... 11. Penicillium, p. 169.
Conidiophores in bundles, api-
cal cells swollen, peri-

thecia stalked.......... 12. Penicilliopsis.
Spores 2-celled; peridium at maturity stel-
Nat is srsnacacece tecws oe Bas Hoes daa Baas 13. Testudina.

Of the thirteen genera and some one hundred to two hundred
species only four of the genera are of interest here. The others
occur on rotting leaves, manure, etc.

Thielavia Zopf ’** (p. 166)

T. basicola (B. and Br.) Zopf.

This, the one species of the genus, is on the boundary between
the Aspergillales and the Perisporiales and is classed by some with
the one, by some with the other order.

The ascocarps, which are the form less commonly seen, are
round, brown, completely closed and have no appendages. The
asexual spores are of two kinds. First: hyaline conidia produced
endogenously within “pistol-formed” conidiophores from the
ends of which they are expelled. Second: short cylindrical conidia
or chlamydospores with a thick brown wall; borne in series of

168 THE FUNGI WHICH CAUSE PLANT DISEASE

three to six on the ends of hyaline branches, Fig. 119. These
conidia fall apart as they age.

The hyaline conidia preponderate in early disease, giving the
surface of the root a mildewed appearance; the dark conidia pre-
ponderate later, covering the
root with a black coating.
Finally, after the host is dead,
the ascocarps appear.

The delicate hyaline myce-
lium wanders through the
affected root disorganizing its
tissue. The superficial myce-
lium is lightly tinted.

Perithecia 80-100 yw; asci
ovate, 8-spored; spores len-
ticular, vacuolate, 1-celled,
chocolate-colored, 8-12 x
4-5 wy; chlamydospores in
chains, at maturity separa-
ting, short-cylindric, about
5-8 x 12 uw; the entire group

: : A ; 25-65 » long; conidia hyaline
‘ig. 119.—Thielavia basicola, showing two
conidial forms and ascus and ascospores. about 10-20 x 4-5 Be

After Van Hook and Zopf. In Europe and Eastern
North America on Aralia quinquefolia, Begonia rubra, Begonia
sp., Catalpa speciosa, Cyclamen sp., Gossypium herbaceum,
Linaria canadensis, Lupinus angustifolius, L. albus, L. luteus,
L. thermis, Nasturtium armoracea, Nemophila auriculata, Nico-
tiana tabacum, N. rustica, Onobrychis cristagalli, Oxalis stricta,
Phaseolus vulgaris, P. multiflorus, Pisum sativum, Senecio elegans,
Trifolium repens, Trigonella ccerulea, Vigna sinensis and Viola
odorata.

Rostrella coffez Zimm. is described as the cause of canker of
coffee in Java.”

Aspergillus Micheli (p. 167)

The ascocarps are small, spherical, indehiscent, smooth bodies
which at maturity are entirely filled with 8-spored asci; spores

THE FUNGI WHICH CAUSE PLANT DISEASE 169

1-celled. The conidiophores, which serve better to characterize
the genus, are swollen at the end, and bear numerous sterigmata
(Fig. 120) on which the spores are borne basipetally in chains.
Sclerotia are sometimes formed.

The members of the genus are all saprophytes but some of them

Fic. 121.— Penicillium,
showing 2 conidio-
phore; a, producing

Fig. 120.— Asper- chains of conidia, c;
gillus, conidio- s, three spores more
phore. After highly magnified.
King. After Longyear.

cause injury to fruit in the tropics; for example, A. ficuum, Reich.
on figs; A. pheenicis Pat. & Del. on dates.

Penicillium Link ” (p. 167)

The ascocarp is much as in the last genus, with the asci 4 to
8-spored. It may develop directly from the mycelium or with the
intervention of a sclerotial stage. The characteristic conidiophore
serves to distinguish the genus by its mode of branching. Fig. 121.
Instead of being apically swollen as in the preceding genus it
branches repeatedly, the branches bearing terminal sterigmata
and giving the conidiophore the appearance of a brush; hence the
name. For species see page 573.

170 THE FUNGI WHICH CAUSE PLANT DISEASE

Mpyriangiacee (p. 165)

Perithecia numerous upon or in a stroma; asci in a pseudo-
parenchymatous substance within the perithecium; spores muri-
form.

Key To Genera or Myriangiacese

Stroma valsoid, perithecia superficial.... 1. Myriangium.
Stroma effused, perithecia immersed.... 2. Myriangiella, p. 170.

Myrangiella orbicularis Zimm. parasitizes coffee in Java.™

Pyrenomycetes ve

The four following orders are usually grouped together as the
Pyrenomycetes; separated from the preceding forms by their closed
ascocarp with the asci arranged in a hymenium. They constitute
a vast assemblage of more than ten thousand species, the large
majority saprophytic and unimportant except in the general
economy as scavengers.

Perisporiales (p. 124)

The present order is characterized by its almost universal
parasitic habit, the evident mycelium and the globoid perithecia
without ostioles, or in one family flattened, ostiolate perithecia.
The mycelium is superficial upon the host and frequently quite
conspicuous.

Key To Famruies or Perisporiales

Perithecia mostly spherical, imperforate
Mycelium white; perithecia with append-
AGES Os eiks 2G wa onda Sisson khmer is 1. Erysiphacew, p. 171.
External mycelium dark colored or want-
ing, perithecia without true append-
ages, but sometimes surrounded by
appendage-like hyphae............ 2. Perisporiacee, p. 189.
Perithecia flattened, shield-shaped, ostio-

VAL aih ln raaeccav anelan aan sk Sade ne 3. Microthyriacee, p. 195.

THE FUNGI WHICH CAUSE PLANT DISEASE 171

Erysiphacez (p. 170) #% 5% 77. 78

This family on account of its abundance everywhere, its sim-
plicity of structure, and its possession of typical ascigerous and
conidial stages forms a favorite type for introductory study of the
Ascomycetes. Its ee eee,
are easy of recognition, form-
ing a coating of white conidia,
conidiophores and mycelium
upon the surface of its hosts
and giving them an appear-
ance much as though they had
been lightly dusted with flour.
Later in the season the white
patches are more or less
liberally sprinkled with the
black perithecia leading to Fic. 122.—I, E. graminis, showing branching
the common name powdery haustoria. 33, Phyllactinia, intercellular
mildew. An important list PYPB# After Smith.
of the economic forms and their hosts has been published by
Halsted.”

The mycelium except in Phyllactinia is entirely superficial. It
is usually quite hyaline and is branched, septate and its cells
uninucleate. It fastens to the host and penetrates its epidermal
cells by uninucleate haustoria which by their various lobings aid
in specific characterization. Figs. 122, 123.

Haustoria may be grouped in three general classes; (1) those
arising directly from the lower surface of the mycelium; (2) those
arising at the side of the mycelium as small semicircular processes;
(3) arising from more or less deeply-lobed lateral swellings of the
mycelium. The relation of the haustoria to the host cells has
been extensively studied by Smith.”

The conidia arise in basipetal succession on simple scattered
conidiophores (Fig. 129); are hyaline, oval or barrel-shaped,
smooth, 1-celled. Neger has shown that they vary greatly in size
with nutrition conditions.”

Conidia germinate readily at once in dry air, better in humid
air, producing from one to three germ tubes. MHaustoria are

172 THE FUNGI WHICH CAUSE PLANT DISEASE

formed at once and the mycelium develops to a more or less
circular colony, producing new conidia in a few days. Artificial
inoculations on susceptible plants, using conidia, usually result
within two to five days in typical mildew spots.

Neger,® who studied the germination of conidia extensively has
shown that light hastens the growth of the germ tubes, which in

many cases are negatively phototropic. Con-
oasis tact stimulus leads to the growth of appres-

8 soria.
eas a The perithecia are subspherical, often some-

ee eee what flattened, white to yellow when young,

showing lobed haus- dark to black and reticulated when mature;

toria. After Salmon. 516 without ostiole but are provided with
appendages of various types, Figs. 130, 133-136, which give main
characters to mark the genera. The appendages serve by hygro-
scopic movements to aid in the distribution of the fungus.2! The
ascospores become free after dissolution of the perithecium by
weathering. The asci are either solitary or quite numerous within
the perithecium and bear two to eight hyaline spores each.

The conidia are short-lived summer spores. The perithecia
mature more slowly and constitute the hibernating condition.
In some instances the ascus-form is unknown;
the fungus is then classified solely by its
conidial stage and falls under the form genus
Oidium (see p. 569.)

In Spherotheca ®* an antheridial and an
odgonidial branch, each uninucleate, are de-
veloped, and cut off by septa. The odgo-
nium enlarges; the antheridium lengthens, yo. 124 Ascogonium-
its nucleus divides, and a septum is run in pee oetechla nuclei.
separating the stalk cell from the antheri- i
dium. The sperm nucleus enters the odgonium and _ fuses
with the odgonial nucleus. Simultaneous with fertilization oc-
curs, from the stalk cell of the odgonium, the development of
a sterile system of enveloping threads which surround and pro-
tect the fertilized odgonium and eventually mature into the
sporocarp. The fertilized oégonium divides several times trans-
versely producing a series of cells, one of which is binucleate.

fophso

THE FUNGI WHICH CAUSE PLANT DISEASE 173

This binucleate cell after fusion of its nuclei develops into the
one ascus characteristic of the genus. The ascus nucleus by
division gives rise to the spore nuclei and the spores are cut out of
the periplasm by reflexion of the astral rays.

In Erysiphe * the odgonium and antheridium arise in a very
similar way, the oédgonium being somewhat curved. Fertilization
is also similar consisting of the union of two gametic nuclei. After
fertilization the odspore nucleus divides and the odégonium de-
velops into a short bent tube, which contains from five to eight
nuclei. Septa now appear cut-
ting off cells, some uninucleate,
some with two or more nuclei.
The ascogenous hyphe develop
a knot and soon divide into
two or three cells each and
give rise to the asci which are > .
ne beginning binucleate. Fic. 125.—Phyllactinia, male and female

In Phyllactinia ** the OOgO- branches; uninucleate odgonium and
nium, antheridium and fertili- *theridium. After Harper.
zations are as in Erysiphe, though the odgonium may be quite
curved so as to make almost a complete turn around the anther-
idium. Fig. 125.

After fertilization the antheridium degenerates and enveloping
protective hyphe arise both from the odgonium and the antheridium
stalk cells. The odgonium becomes three to five nucleate and
develops to a row of cells of which the penultinate cell has more
than one nucleus. The ascigerous hyphe arise from this binu-
cleate cell, perhaps also from other cells of the series, become
septate and form the asci either terminally, laterally or inter-
calary. The young ascus is binucleate, fusion follows and the
spores develop as in the preceding genera.

The family contains, according to Salmon,“ forty-nine species
and eleven varieties, according to Saccardo more than one hun-
dred species. These are parasitic on some one thousand five
hundred hosts, some of them upon economic plants and of
serious harmfulness.

The matter of delimiting species and even genera is often diffi-
cult, owing to intergrading forms. This question is complicated

174 THE FUNGI WHICH CAUSE PLANT DISEASE

still further by biologic specialization such that forms which are in-
distinguishable under the microscope show in inoculation tests dif-
ferent abilities regarding host infection. Thus Neger,®Salmon,***
Reed,®” and others have shown that spores borne on a particular
host are capable of infecting only that host or in other cases only
nearly related species of the same host genus. Forms which can
pass from one genus to another are less common. Forms morpho-
logically distinct are regarded as separate species. Differentiations
within such species, regarding the species of host plant which they
parasitize, give rise to “biologic species” or ‘‘ biologic varieties.”

Reed * writes of these biologic forms thus:

“So far as investigated, Erysiphe cichoracearum, is the only
one with doubtful exceptions, . . . shown to be capable of in-
fecting plants belonging to more than one genus.”

“There are other cases where the mildew is limited closely to
plants of a single genus,’’ and “Several cases are recorded where
the mildew from one species will not infect other species of the same
genus. Most of these claims, however, rest on insufficient data.”

Some morphological species show a very wide range of hosts;
one species, Phyllactinia corylea is known on forty-eight genera
in twenty-seven families, others are limited to single genera or
to single species of host plant. Two, three, and even five species
are recorded for some species of host.

Geographically the Erysiphacee are widely distributed, prac-
tically of world distribution, but they are more abundant in the
temperate zones than elsewhere.

A pycnidium-bearing parasite, Cicinnobolus, p. 494, is quite
frequently found on the mycelium and conidiophores of the Ery-
siphacee.

Owing to the extreme variability of the perithecial characters
and the almost promiscuity of host selection this family presents
a most difficult problem to the taxonomist who must either segre-
gate or “lump” species. No middle ground seems open at present.

Key to SusraMities AND GENERA oF Erysiphacese
Mycelium wholly external to the tissues of the
host plant, usually sending haustoria
into the epidermal cells only, perithecial
appendages various, more or less flaccid I. Erysiphee.

THE FUNGI WHICH CAUSE PLANT DISEASE 175

Perithecial appendages indeterminate,
similar to the mycelium, simple or ir-

regularly branched
Perithecia containing a single ascus... 1. Spherotheca, p. 175.
Perithecia containing several asci..... 2. Erysiphe, p. 177.

Perithecial appendages determinate
Appendages hooked or coiled at the
BPONS eee one odie Sede vlna acne 3. Uncinula, p. 180.
Appendages dichotomous at the apex
Perithecia containing a single ascus.
Perithecia containing several asci.. .
Mycelium with special intercellular haus-
toria-bearing branches which enter the
host by the stomata; perithecial ap-
pendages rigid, with a bulbous base... II. Phyllactinies.
A single genus...................000. 6. Phyllactinia, p. 187.

. Podosphera,; p. 182.
. Microsphera, p. 185.

oF

Spherotheca, Léveillé

Perithecta subglobose; appendages floccose, brown or hyaline,
spreading horizontally and often interwoven with the mycelium,
simple or vaguely branched, frequently obsolete; ascus single,
8-spored. Five species, according to Salmon an Engler and
Prantl” give fourteen.

S. humuli (D. C.) Burr.

Amphigenous; mycelium usually evanescent; perithecia usually
somewhat gregarious, but varying from scattered to cespitose,
58-120 » in diameter; cells small, averaging 15 »; appendages
few or numerous, usually long, ‘often exceeding nine times the
diameter of the perithecium, more or less straight, septate, dark
brown throughout: variations are, short, flexuose, pearly-brown,
white or even obsolete. Ascus broadly-elliptic to subglobose,
rarely abruptly stalked, 45-90 x 50-72 uw; spores 20-25 x 12-18 up,
rarely larger, averaging 22 x 15 yp.

Conidia (=Oidium fragariez) ovate, white, membrane smooth.

Salmon ® has shown that subjecting the conidia of this variety
to low temperature, 0° two hours, increases their germinating power.
Sowing ascospores from the hop, on hop, Potentilla and Spirea he
secured infection only on the hop.*! Conidia from hop infected
hop but not Spirea.

176 THE FUNGI WHICH CAUSE PLANT DISEASE

The species is cosmopolitan and among its numerous hosts are
the economic genera Dipsacus, Fragaria, Humulus, Phlox, Pyrus,
Rosa, Ribes, Rubus, Scabiosa, Spirea and Viola.

It is a common rose mildew of America and England and is also
especially destructive on the strawberry.

S. humili var. fuliginea. (Schl.) Sal.

Perithecia usually smaller than in the last, sometimes only 50 z
in diameter, wall usually harder and more brittle, cells larger, ir-
regularly shaped, averaging 25 p;
appendages usually short, pale
brown; spores 20-25 x 12-15 x.

Throughout Europe, Asia and
North America.

It is recorded on Arnica,
Calendula, Coreopsis, Fragaria,
Gaillardia, Impatiens, Phlox,
Scabiosa, Taraxacum, Verbena,
Viola, and several other non-
economic genera.

= S. pannosa (Wallr.) Lév.??-*
Fig, 126.8. mors-uve, » perithecium © Mycelium persistent, forming
discharging its single ascus which ‘

contains eight spores. After Long- dense satiny patches on the

asad stem, calyx, petiole, and rarely
on leaves, at first shiny white, then becoming gray, buff or
rarely brown; perithecia more or less (usually completely) im-
mersed in the persistent mycelium, globose to pyriform, 85-120 p
in diameter, usually about 100 ‘u; cells obscure, about 10 » wide;
appendages few, often obsolete, very short, tortuous, pale brown,
septate; ascus broadly-oblong to globose, 88-115 y, averaging
100 x 60-75 yw; spores 20-27 x 12-15 p.

Conidia (=Oidium leucoconium) ovoid, 20-30 x 13-16 ux,
hyaline; conidiophores short.

Hosts: peach and rose; cosmopolitan.

The conidia are very common on the rose, but the perithecia
are rare. What often passes for this species on roses in America
is in reality S. humili.“®

S. mors-uve (Schw.) B. & C.94%

The mycelium at first white, is exceptional among the Erysiphee

THE FUNGI WHICH CAUSE PLANT DISEASE 177

in that it later becomes quite brown. It is found in closely felted
patches on stems and fruit. Perithecia begin to form in June.

Amphigenous; mycelium persistent, at’ maturity forming dense
pannose patches of brownish hyphe; perithecia gregarious, more
or less immersed in the persistent mycelium, subglobose, 76-110
»# in diameter; cells large, at first well defined, then becoming
obscure, 10-25 ww wide; appendages usually few or even obsolete,
pale-brown, short, rarely longer, up to five times the diameter of
the perithecium, tortuous; ascus elliptic-oblong to subglobose,
70-92, rarely 100 x 50-62 yu; spores 20-25 x 12-15 yp.

On wild and cultivated species of Ribes in America; recently
introduced into Europe where it is very destructive.

S. lanestris Hark. occurs on various species of oaks in the United
States.

Erysiphe Hedwig (p. 175)

Perithecia globose, or slightly depressed, rarely concave; ap-
pendages floccose, simple or irregularly branched, sometimes
obsolete, usually more or less similar to the mycelium and inter-
woven with it; asci several, 2 to 8-spored.

Salmon “ recognizes eight species; Engler and Prantl,” twenty.

E. polygoni D. C.”

Amphigenous; mycelium very variable, persistent, thin, effused
and arachnoid, rarely thick, or more often evanescent; perithecia
gregarious or scattered, usually rather small,
averaging 90 y, but ranging from 65 to 180 yu;

cells usually distinct, 10-15 » wide; append- 182
ages very variable in number and length,
few or many, distinct or more or less inter-

woven with the mycelium, brown or colorless; Papen oles:
asci 2-8 or rarely as many as 22, variable in the asci. After Sal-
shape and size, usually small and ovate, with ™°™
or without a short stalk, 46-72 x 30-45 u; spores 3-8 rarely 2,
19-25 x 9-14 yp.

Conidiophores (=Oidium balsamii) medium; conidia ovate,
hyaline.

One of the commonest species, especially destructive to the pea
and turnip. It was studied by Salmon on one hundred ninety host

178 THE FUNGI WHICH CAUSE PLANT DISEASE

species belonging to eighty-nine genera; one hundred forty-six
more hosts, some doubtful, are reported. Among the economic
host genera are Adonis, Alyssum, Anemone, Aquilegia, Brassica,
Calendula, Catalpa, Clematis, Cucumis (?), Cucurbita (?), Dahlia,
Daucus, Delphinium, Diervilla, Dipsacus, Fagopyrum, Lupinus,
Lycopersicum, Medicago, Peonia, Phaseolus, Pisum, Tragopogon,
Trifolium, Verbena, Vicia, Scabiosa, Symphytum, Valeriana.

This is the most variable species of this genus varying widely
in its every character. It includes several species which have by
some been set aside as distinct, e. g.,
E. martii, E. umbelliferarum and
E. liriodendri.

Salmon * found that the conidia
of this form grown on Trifolium
pratense were unable to infect other
species of Trifolium.

E. cichoracearum D. C.*

Amphigenous; mycelium usually
evanescent, rarely persistent, white

-—" or sometimes pink; perithecia gre-
C > garious or scattered, 80-140 or
i () rarely 180 y; cells variable, often

very distinct, 10-20 »; appendages
variable in number and size, some
Fic. 128.—E. cichoracearum, asci shade of brown; asci usually nu-

Sect spones: Alfer Salman, merous, about 10-15, but varying
from 4 to 36, variable in size and shape, narrowly ovate or
subcylindric to broadly-ovate, more or less stalked, 58-90 x
30-35 yw; spores 2, rarely 3, 20-28 x 12-20 BL.

Conidiophores (=Oidium ambrosiz Thiim), short; conidia
minute, elliptic, white, 4-5 x 7-5.3 nu. The species is quite vari-
able sometimes closely approaching E. polygoni.

Cosmopolitan. The hosts are very numerous, among them
being: Borago, Calendula, Centaurea, Cichorium, Clematis,
Cucurbita, Dahlia, Helianthus, Humulus, Mentha, Nicotiana,
Phlox, Tragopogon, Valeriana, Verbena, Symphytum. It is of
especial import on composites and cucurbits.

Reed ® has made very extensive culture studies of this species

THE FUNGI WHICH CAUSE PLANT DISEASE 179

and concludes that the same form of ‘“Erysiphe cichoracearum
D. C., occurs on at least eleven species of the cucurbits, belonging
to seven genera, infection occurring in these cases in fifty per cent
or more of the trials. Six other species were also infected, but in
a smaller percentage of cases. . . . It is also plain that the biologic
form of Erysiphe cichoracearum, occurring on so
many cucurbits is not entirely confined to the
species of this one family. Out of fifty-four
leaves of Plantago rugelii, a species belonging to
the Plantaginacee, which were inoculated, ten
became infected. . . . Furthermore out of ten
leaves of squash seedlings, inoculated with conidia
from plantain, six became infected . . . and the
sunflower, Helianthus annuus, was infected in
thirty-five per cent of the trials in which conidia
from the squash were sown on leaves of seed-
lings. ... The cucurbit mildew could not be
transferred to asters and goldenrods nor was the
mildew occurring on these in nature able to in-
fect the squash. Neither the aster mildew nor
the cucurbit mildew proved able to infect a
goldenrod, Solidago cesia. Nor was the mildew
on this host able to infect asters or squashes.”’
E. taurica Lév. is found in Europe, North
Africa and Asia on Capparis, Cicer, Clematis
and various other hosts. .
E. graminis D. C. Fic. 129.—E. gra-
: A minis, conidial
Usually epiphyllous, rarely amphigenous; myce- stage. After Sal-
lium more or less persistent, forming scattered ™°™
patches, at first white, then brown or gray; perithecia large,
135-280 yu, usually about 200 », scattered or gregarious, cells ob-
scure; appendages rudimentary, few or numerous, very short,
pale brown; asci numerous, 9-30, cylindric to ovate-oblong, more
or less long-pedicellate, 70-108 x 25-40 yu; spores 8, rarely 4,
20-23 x 10-13 », seldom produced on the living host plant.
Conidial form (=Oidium monilioides) with a grayish cast; coni-
diophores medium tall; conidia ovoid, white or sordid, 25-30x 8-10 nu.
It is found on a large number of species of the Graminez in-

180 THE FUNGI WHICH CAUSE PLANT DISEASE

cluding species of Avena, Festuca, Hordeum, Phleum, Poa, Sac-
charum, Secale, and Triticum.

The asci are peculiar in that they usually contain undifferenti-
ated granular protoplasm, not spores, though in some cases the
spores, normally 8, are present. Wolff 1° found that after a few
days in water the undifferentiated ascoplasm developed spores
which proceeded to normal germination.

This species on grasses shows no morphological differences, yet
inoculation tests have revealed in it numerous biologic varieties.
Reed ®” summarizes the results of his own work together with
that of Marchal !! and Salmon ? as follows:

“So far as tested, all species of Avena are susceptible to the
oat mildew. All species of Triticum are likewise susceptible to
the wheat mildew. We find, however, that certain varieties of
Triticum dicoccum are practically immune to the wheat mildew.
Other varieties of this same species are entirely susceptible. Some
species of Hordeum are immune to the barley mildew, and the
same seems to be true of certain species of Secale with reference
to the rye mildew.

“To these general statements there are two possible exceptions.
Marchal states that the oat mildew will infect Arrhenatherum
elatius. Salmon, however, obtained a negative result with the
oat mildew on this grass. The evidence is not conclusive either
way. The other exception is that, according to Salmon, conidia
from wheat can infect Hordeum silvaticum.

“Tt would seem then that under normal conditions there are
well-defined forms of Erysiphe graminis occurring respectively
on the species of each of the four cereals.”

It is thought that some hosts may act as bridging species and
enable the parasite to pass from one host to another to which it
could not pass directly.

Uncinula Léveillé (p. 175)

Perithecia globose to globose-depressed; appendages simple or
rarely once or twice dichotomously forked, uncinate at the apex,
usually colorless, rarely dark brown at base or throughout; asci
several, 2 to 8-spored.

There are eighteen or twenty species.

THE FUNGI WHICH CAUSE PLANT DISEASE 181

U. necator (Schw.) Burr.1% 104 105

Amphigenous; mycelium subpersistent; perithecia usually epi-
phyllous, occasionally hypophyllous or on the inflorescence,
more or less scattered, 70-128 y; cells distinct, rather irregular
in shape, 10-20 jy; appendages very variable in number and
length, 7-32, rarely up to 40, 1 to 4-times the diameter of the
perithecium, septate, thin walled, light or dark amber-brown bas-
ally, rarely branched, asci 4-6 rarely up to 9, broadly-ovate or
ovate-oblong to subglobose, with or with-
out a short stalk, 50-60 x 3040 u; spores
4-7, 18-25 x 10-12 yu.

Conidial form (=Oidium tuckeri), coni-
diophores short; conidia elliptic, oblong,
or obtusely rounded, 2 to 3-catenulate,
hyaline, 25-30 x 15-17 up.

Hosts Vitis, Ampelopsis and Actinidia.
One of the worst pests of the family.

The mycelium is thin walled and spar-
ingly septate. The haustoria arise from
lobed lateral swellings of the hyphe,
penetrate the epidermis with a filamen-
tous projéction and swell within the host
cell to a bladder-like body. The para-
sitized cells and later the neighboring yy. 130.—U. necator. IL.
ones turn brown and die. Perithecium showing /, ap-

ee : Scant . pendages, and a, asci. IV.
The conidia germinate readily in moist Group of asci removed

air or in water, sending forth from one aes, pecan ‘after
to several germ tubes. Vial.

The perithecia are found well developed as early as June or
July in the United States and are rather evenly scattered over
the affected surfaces. Bioletti 1°° says that a period of warm moist
weather which favors luxuriant mycelial growth, followed by sud-
den lowering of temperature to about 50° F., favors their most
rapid formation. They are at first hyaline, later brown. After
their form and walls become definite, usually during winter, the
appendages develop as outgrowths from the outer walls. During
winter the appendages break off. Galloway ™ failed to secure
germination of ascospores earlier than February or March, but

182 THE FUNGI WHICH CAUSE PLANT DISEASE

perithecia which had been exposed to the weather until spring
and were then placed in a hanging drop culture afforded spores,
some of which grew though many of them burst as they emerged
from the perithecium. Ascospores are known to have remained
viable for at least eighteen months.!°° No successful infections
were made from ascospores.

Though perithecia are frequently found in America they were
not found in Europe until 1892 1” and are now found there but
rarely. It appears that in their absence the fungus hibernates in

Fig. 131.—U. necator. Photomicrographs of perithecia on surface of leaf.
A, Magnified 8 times. B, Magnified 35 times. After Bioletti.

specially resistant cells of the mycelium which develop within
knotty swellings near the haustoria.*”°

U. salicis (D. C.) Wint. on willow and poplar in Europe, Asia,
and America, U. aceris (D. C.) Sacc. and U. circinata C. &. P.
on maple are common species. U. flexuosa Pk. occurs on Aésculus.
and elm, U. clandestina (Biv.) Schr. on elm, U. prunastri (D. C.)
Sacc. on species of Prunus, especially P. spinosa in Europe. U.
mori Miy. is on Morus in Japan.*°! Several other species of small
importance affect numerous hosts.

Podosphera Kunze (p. 175)

Perithecia globose or globose-depressed; ascus solitary, sub-
globose, 8-spored; appendages equatorial or apical, dark-brown
or colorless, dichotomously branched at the apex, branches simple

THE FUNGI WHICH CAUSE PLANT DISEASE 183

and straight or swollen and knob-shaped; appendages rarely of
two kinds, one set apical, brown, rigid, unbranched or rarely
1 to 2-times dichotomous at the apex, the other set basal, short,
flexuous, frequently obsolete.

Salmon *® recognizes four species; Engler and Prantl” seven.

P. oxyacanthe (D. C.) De Bary 1 19

Amphigenous; mycelium variable, persistent in thin patches
or evanescent; perithecia scattered or more or less gregarious,
subglobose, 64-90 yu; cells 10-18 4; appendages spreading more

Fic. 132.—P. oxyacanthe. a, perithecium showing the appendages with
tips; b, the one large ascus containing eight spores; c, the summer
spore-form; d, a spore germinating in water. After Longyear.

or less, equatorial, variable in number and length, from 4-30 in
number and from 1-6 or even 10-times the diameter of the
perithecium, usually unequal in length, dark brown for more than
half their length from the base, apex 2 to 4-times dichotomously
branched, branches usually short and equal, ultimate branches
rounded, swollen, and more or less knob-shaped, Fig. 133; ascus
broadly obovate, or subglobose, 58-90 x 45-75 uw; spores 8, rarely
6, 18-30 x 10-17 ux.

Conidia (=Oidium crategi).

Salmon finds the species very variable but cannot set aside as
separate species P. tridactyla and P. myrtillina as is done by some
authors. On some hosts perithecia are rare. It is thought that
the mycelium remains alive over winter.

Hosts: Amelanchier, Crataegus, Diospyros, Prunus, Pyrus,

184 THE FUNGI WHICH CAUSE PLANT DISEASE

Spirea and Vaccinium. Especially damaging to cherry and apple.
Throughout the northern hemisphere.

P. tridactyla (Wal.) De Bary is considered by Salmon 2” as a
variety of the last species. Hosts: Plum and
other species of Prunus and of Spirea.

Similar to the preceding in habit and general

t~ character but differing in more critical charac-

ters. Perithecia 70-105 yu; cells 10-15 yw; ap-

Fic. 133.—P. oxycan- pendages 2-8 usually 4, 1 to 8times the

ont eee ae diameter of the perithecium, apical in origin,

ea more or less erect, apically 3-5 or 6-times

dichotomously branched, primary branches usually more or less

elongate, sometimes slightly recurved; asci globose or subglobose,
60-78 x 60-70 yu; spores 8, 20-30 x 13-15 uy.

Chiefly European but found also in Asia and America.

P. leucotricha (E. & E.) Salm.

Mycelium amphigenous, persistent, thin, effused; perithecia
densely gregarious, rarely more or less scattered, 75-96 yu, sub-
globose, cells 10-16 »; appendages of two kinds, one set apical
the other basal; apical appendages 3-11 in number, more or less
widely spreading, or erect-fasciculate, 4 to 7-times the diameter
of the perithecium, apex undivided and blunt or rarely once or
twice dichotomously branched, brown basally; basal appendages
nearly obsolete or well developed, short, tor-
tuous, pale brown, simple or irregularly branched;
ascus oblong to subglobose, 55-70 x 44-50 uy,
spores 22-26 x 12-14 yw, crowded in the ascus.

Conidia (=Oidium farinosum): ellipsoid, trun-
cate, hyaline, 28-30 x 12 uy.

Primarily American but occurring in Europe
and Japan. A most serious pest of the apple.
This and P. oxyacanthe, the apple mildews of
America, have been variously treated by writers Fis. 1547 P- ye
so that the literature presents an almost inex- pendage tips.
tricable tangle as has been pointed out by Pam- alter: Seliaon.
mel *“ and by Stewart,**! Podosphera oxyacanthe being fre-
quently reported instead of P. leucotricha. Spherotheca mali
and Podosphera oxyacanthe have also been much confused, due

THE FUNGI WHICH CAUSE PLANT DISEASE 185

to similarity of habit and the frequent abnormal development
of the appendages, so that the published references are not always
reliable.

Microsphera Léviellé (p. 175)

Perithecia globose to subglobose; asci several, 2 to 8-spored,
‘ appendages not interwoven with the mycelium, branched in a
definite manner at the apex, usually dichotomously and often
very ornately, rarely undivided or merely once dichotomous.

According to Salmon “® there are thirteen species; Engler and
Prantl” recognize thirty.

M. grossularie (Wal.) Lév.

Epiphyllous or amphigenous; mycelium evanescent or sub-
persistent; perithecia scattered or densely aggregated, globose-
depressed, 65-130 y; cells 14-20 uy;
appendages 5-22, colorless, 1-134
times the diameter of the perithe-
cium, 4 to 5-times closely dichoto-
mously branched, branches of first 4 a5
and second order very short, all pyo. 135.—M. grossularie, append-
segments deeply divided, tips not age tips. After Salmon.
recurved; asci 4-10, broadly ovate or oblong, usually with a very
short stalk, 46-62 x 28-38 yw; spores 4-6, rarely 3, 20-28 x
12-16 uw.

On five species of Ribes and two of Sambucus. This is the
common European gooseberry-mildew, which is not common in
America except on the elder.

M. berberidis (D.:C.) Lév. occurs on the barberry in Europe
and Asia.

M. alni (Wal.) Salm.

Amphigenous; mycelium evanescent or persistent; perithecia
scattered to gregarious, globose-depressed, very variable in size,
usually small, 66-110 yu, or even up to 135 yu; cells 10-15 u
wide; appendages variable in number (4-26) and length, ls to
21% times the diameter of the perithecium, more or less rigid,
colorless throughout or amber-brown at base, apex variously

186 THE FUNGI WHICH CAUSE PLANT DISEASE

(but not always) more or less closely 3 to 6-times dichotomously

branched, tips of ultimate branches regularly and distinctly re-

curved; asci 3-8, ovate to ovate-globose, 42-70 x 32-50 u, usually
but not always short stalked; 4 to
8-spored; spores 18-23 x 10-12 yn.

This species is the most variable of
the Erysiphee showing large latitude in
number of spores in the ascus, in length,

4 é color and branching of appendages, in °

Fic. 136.—M. alni, appendage size of perithecia. It occurs upon very

tbe: “Bee Selman numerous hosts. The economic ones on
which it is most common are: Syringa, Lonicera, Alnus, Betula,
Quercus, Carya, Castanea, Juglans, Platanus.

It is confined to the northern hemisphere.

Salmon recognizes in addition to the typical form six varieties.
Those of economic importance are:

(a) extensa (C. & P.) Salm., a robust form on various American
species of oaks;

(b) calocladophora (Atk.) Salm., also a robust form on American
oaks but having pseudo-trichotomously branched appendages
and large spores;

(c) vaccinii (Schw.) Salm., in America on Catalpa and various
genera of Ericacez is a small-spored, long-appendaged form. It
includes M elevata on Catalpa;

(d) lonicere (D. C.) Salm., on species of Lonicera in Europe.

M. diffusa C. & P.

Amphigenous; mycelium persistent, thin and effused, or sub-
persistent and forming vague patches, or quite evanescent; peri-
thecia scattered or gregarious, globose-depressed, very variable in
size, 55-126 in diameter, averaging 90-100 yu, cells 10-20
wide; appendages very variable in number and length, 4-30, or
rarely crowded and as many as 50, 114 to 7-times the diameter of
the perithecium, smooth, aseptate or 1 to 3-septatein the lower half -
colorless or pale brown towards the base, flaccid when long, thin-
walled above, becoming thick-walled towards the base, apex 3 to 5-
times dichotomously or subdichotomously divided, branching dif-
fuse and irregular, branches of the higher orders sub-nodulose,
often apparently lateral, tips of ultimate branches not recurved;

THE FUNGI WHICH CAUSE PLANT DISEASE 187

asci 4-9, 48-60. x 28-30 u, ovate-oblong with a very short stalk;
spores 3-6, usually 4, 18-22 x 9-11.

Hosts: Desmodium, Glycyrrhiza, Lespedeza, Phaseolus, Sym-
phoricarpos. ;

M. bete Vanha ‘™ has recently been described as a species in-
jurious to the beet. It is said to resemble E. polygoni but that
cross inoculation between the beet and clover could not be made.

M. ferruginea Erik. is found on cultivated Verbenas}” in
Sweden.

M. euphorbie (Pk.) B. & C. occurs on various hosts in America
and Asia, including Astragalus, Colutea, Cuphea and Euphorbia.
Its only economic importance is as the cause of a disease of the
roselle *° and cowpea "* on which it is very common.

Amphigenous; mycelium usually subgeniculate; perithecia gre-
garious in floccose patches or scattered, 85-145 wu, rarely 180 yn,
cells 10-15 yw; appendages 7-28, usually narrow, more or less
flexuose and nodose, 2.5 to 8 times the diameter of the perithecium,
colorless above, 3 to 4-times dichotomously branched, branching
irregular and lax; asci 4-13, rarely up to 26, ovate or ovate-oblong,
short-stalked, 48-66 x 26-35 uw; spores usually 4, rarely 3, 5 or 6,
16-21 x 10-12 up.

Phyllactinia Léveillé (p. 175)

Perithecia large, globose-depressed to lenticular; asci many, 2
or 3-spored; appendages equatorial, rigid, acicular, with a bul-
bous base; apex of perithecium with a mass of densely crowded
branched outgrowths.

Typical epidermal haustoria are not produced but the mycelium
sends special branches through the stomata into the intercellular
spaces of the leaf.1!4 These branches attain some length and con-
stitute a limited internal mycelium, a character that is considered
by some as of sufficient importance to set the genus apart in a
separate family. The internal mycelium gives off haustoria which
penetrate cells of the mesophyll. The appendages exhibit strik-
ing hygroscopic movements and aid in dissemination.

Only one species is recognized by Salmon.

P. corylea (Pers.) Karst.

Hypophyllous or rarely amphigenous; mycelium evanescent

188 THE FUNGI WHICH CAUSE PLANT DISEASE

or more or less persistent; perithecia usually scattered, rarely
gregarious, 140-270 yu, rarely up to 350 y; cells rather obscure,
15-20 y; the apical outgrowth becomes mucilaginous attaching
the perithecium firmly to places where it may fall; appendages

FW. ANDERSON, ad. ant, dol,
: 6
Fic. 137.—Phyllactinia corylea. 1. Natural size, on
chestnut leaf. 2. Perithecium enlarged. 3. Two asci.
4. Three spores. 5. Conidia-bearing hyphae. 6. Co-
nidium germinating. After Anderson. .
5-18, equatorial, 1 to 3-times the diameter of the perithecium;
asci 5-45, subcylindric to ovate-oblong, 60-105 x 25-40 yw, more
or less stalked, 2, rarely 3-spored; spores 30-42 x 16-25 uy.

Conidia (=Ovulariopsis) acrogenous, solitary, hyaline, sub-
clavate.

On Magnolia, Liriodendron, Berberis, Xanthoxylum, Ilex, Celas-
trus, Acer, Desmodium, Crategus, Heuchera, Ribes, Hamamelis,
Fraxinus, Asclepias, Catalpa, Cornus, Ulmus, Betula, Alnus, Cory-
lus, Ostrya, Carpinus, Quercus, Castanea, Fagus and Typha.

THE FUNGI WHICH CAUSE PLANT DISEASE 189

Perisporiacee (p. 170)

’ Aérial mycelium covering the substratum with a dark growth,
rarely absent, usually astromate. Perithecia on the mycelial threads
or on a stroma, black, more or less globose, without opening or
appendages, although in some genera (Meliola, etc.) mycelial out-
growths from the base of the perithecium simulate appendages.
Asci elongate, numerous; spores various; paraphyses none.

Chiefly parasites, although several genera are saprophytes.
About three hundred species.

Aside from ascospores, in some species conidia of one or several
forms are known. These may be borne in pycnidia or uncovered
on hyphe. Apiosporium is especially rich in the number of.its
conidial forms.

Key to Genera oF Perisporiacee

Spores 1-celled
Spores not curved

Spores hyaline................00008 1, Anixia.
Spores brownish..............-...+- 2. Orbicula.
Spores curved, green. ...........+.005- 3. Pseudomeliola.

Spores 2-celled
Spores, at least when immature, ap-
pendaged. . 6. 2c icctseavecee evens 4. Zopfiella.
Spores not appendaged
Perithecia borne on the aérial mycelium
Spores not enlarging after maturity
Spores smooth

Aérial mycelium prominent. ... 5. Dimerosporium,p. 191.
Aérial mycelium none, or poorly
developed
Asci cylindric-clavate; para-
BICOL 2. diz. nasa sieves bea cia 6. Parodiella.
Asci saccate, large; sapro-
phytes. «6s sesseeses ee 7. Zopfia.
Spores finely echinulate.......... 8. Marchaliella.
Spores enlarging after maturity ... 9. Richonia.
Perithecia borne on a hairy stroma.... 10. Lasiobotrys, p. 191.

Spores 3 or more celled
Aérial mycelium none or poorly developed

190 THE FUNGI WHICH CAUSE PLANT DISEASE

Spores with cross walls only
Spores elongate to cylindric

Spores 4-celled, saprophytes. ..... 11. Perisporium. :
Spores 4 to 8-celled; parasites. ... 12. Schenckiella.
Spores needle-formed. .......-.+++- 13. Hyaloderma.
Spores muriform
Spores brown .. ......-eeeeeeees 14. Cleistotheca.
Spores hyaline.........--.-.+++- 15. Saccardia.

Aérial mycelium prominent
Spores with cross walls only
Spores hyaline
Saprophytic. .............-0ee ee 16. Scorias.
Patasities. coccse cease snc tae ease 17. Zukalia, p. 191.
Spores brown
Perithecia without apparent ap-
pendages
Perithecia rounded, opening
irregularly. ............ 18. Antennaria, p. 192.
Perithecia elongate, clavate,
opening by regular slits.. 19. Apiosporium, p. 191.
Perithecia appearing to have

appendages
Stromatic.................-. 20. Limacinia, p. 193.
Not stromatic.............. 21. Meliola, p. 193.

(Some species of Meliola have muri-
form spores)
Spores muriform
Spores with an appendage at each

ONG: nae nots cute neta eee 22. Ceratocarpia.
Spores not appendaged
Subicle crustose. ............... 23. Capnodium, p. 192.
Subicle radiate. ................ 24. Pleomeliola, p. 193.

The genera of interest as pathogens induce disease rather by
covering, shading and smothering leaves with dense sooty-black
coatings than by parasitizing their hosts. They are not strictly
speaking parasites but live saprophytically upon the surfaces of
leaves, fruit and twigs often subsisting upon insects or insect
exudations, the so called ‘honey dew.”

THE FUNGI WHICH CAUSE PLANT DISEASE 191

Dimerosporium Fuckel (p. 189)

Perithecia depressed-globose, membrano-carbonous; asci clavate
to ovate, 8-spored; spores 2-celled, hyaline or brownish; mycelium
abundant, dark, forming a film and often bearing conidia on
conidiophores.

D. mangiferum Sacc. does some harm to the mango.

D. pulchrum, Sacc. grows upon the leaves of several woody
plants, such as privet, Lonicera, Carpinus and
Cornus. Conidia=Sarcinella heterospora.

D. collinsii (Schw.) Thiim., forms witches
brooms on the service berry.

Lasiobotrys Kunze (p. 189) a ne

Perithecia superficial, globose, minute, Bree ice ae
black, aggregated in botryose fashion, stro- After Winter.
mate; asci cylindric, 8-spored; spores oblong, 2-celled, hyaline.

The one species L. lonicere Kze. forms dark coatings on honey-
suckle leaves in Europe, North Africa and Siberia but does little
or no harm.

Zukalia Saccardo (p. 190)

This genus is like Meliola except in its hyaline spores and in
its perithecium.
Z. stuhlmanniana is on seedling cocoanuts and other palms.

Apiosporium Kunze (p. 190)

Perithecia superficial, minute, globose to pyriform, membra-
nous or carbonous; asci ovate to clavate, 8-spored; spores
globose to oblong, hyaline; paraphyses none. Conidia=Torula,
Fumago, Chetophoma, ete.

Several forms are known to constitute sooty coatings on leaves
of woody plants, subsisting on insect secretions. The specific
limitations in the genus have not been satisfactorily worked out
owing to the comparative rarity of the ascigerous stages.

A. salicinum. (Pers.) Kze. is common on leaves of many species
of woody plants.

Perithecia brownish, gregarious, globoid-oblong, composed of

192 THE FUNGI WHICH CAUSE PLANT DISEASE

minute cells as in the Erysiphacee; spores ovate, guttulate, hyaline,
10 x 8 uw; conidia of various kinds, formed from the bases of the
perithecia, (a) multicellular macroconidia, (b) unicellular micro-
conidia, (c) gemme.

A. brasiliense Noack is reported on grape **” in Brazil.

Various species also occur on numerous woody and herbaceous
plants which are infected with aphids or upon which their “honey
dew” falls.

Antennaria Link differs but little from Apiosporium.

A. pithyophila Nees. occurs on leaves of fir; A. elaophila Mont.

Fic. 139.—Apiosporium salicinum. After Anderson.

on the Olive; A. setosa Zimm. on coffee; A. footi B. & D. com-
monly on green house plants; A. piniphilum Fel. on fir.

Capnodium Mont. (p. 190)
This is easily distinguished from genera of similar habit by its
muriform spores.

C. quercinum Pers. occurs on oak; C. taxi S. & R. on Taxus;
C. feedum Sacc. on Oleander; C. coffee Del. on coffee; C. tilize

THE FUNGI WHICH CAUSE PLANT DISEASE 193

Fel. on Tilia; C. citri B. & P. on leaves of citrus fruits in Europe
and America.

C. stellatum Bern. and C. guajave Bern. cause sooty mold
on various trees in the tropics; *** C. corticolum McAlp. on citrous
trees in New South Wales ** and Australia; C. javanicum Zimm.,
on coffee.**° (C. meridionale Arnaud is on Oleander, oak, and
olive, in Europe; * C. olea Arnaud **! on olive in France.

Limacinia tangensis P. Henn. is on the mango and cocoanut in
Africa.

Pleomeliola hyphznes P. Henn. is on leaves of Hyphene in
Africa.

Meliola Fries (p. 190)

Perithecia globose, surrounded by dichotomously branched
hyphz which resemble the appendages of the Erysiphaces; asci
short, broad, 2 to 8-spored;
spores oblong, 2 to 5-septate,
rarely muriform; paraphyses
none.

This is a genus of over one
hundred thirty species, whose
mycelium grows superficially
upon leaves and twigs.

M. camelliz (Catt.) Sacc. oc-
curs on Camellia.

Mycelium, copious, black,
bearing various sporing bodies;
perithecia black, spherical, 80—
150 u., containing several 8-
spored asci; spores 16-18 x 45 yu,
olivaceous, 4-celled. Stylo-
spores ovoid, 5 y, hyaline, borne
sansiabinreicaiie i Arta wey Fic. 140.—M. camelliz. 3, pycnidium
may be as much as 1 or 2mm. “ ‘and spores. 4, other form of pyc-
high; pycnidia globose resem- ace ae and as-
bling the perithecia but smaller,
containing spherical spores of about the same size as the stylo-
spores. Chlamydospores are also formed by the breaking up of

194 THE FUNGI WHICH CAUSE PLANT DISEASE

the mycelium. Fumago camellia Catt. is a conidial form of this
species.

M. penzigi Sacc.4*1"" is found on Citrus forming a sooty black
mold. It subsists on “honey dew,” following principally certain
insects as Aleyrodes, Ceraplastes, Dactylopius, and Aphis. The
species is quite similar to the preceding.

The hyphe are from olive-green to dark brown and when old
are connected into a compact membrane. The fungus is entirely
superficial, possessing, however, small knob-like projections for
attachment and large discs (hyphopodia). Reproduction is by
conidia, pycnidia, stylospores and perithecia.

Webber says:

“Several forms of conidia are produced, some being but slight
modifications of the common cells of the mycelium, while others
are compound spores. Pycnidia are small, spherical black repro-
ductive bodies, about 40 » in diameter, and are usually present
in considerable numbers in the mycelium. They may be readily
seen with a strong magnifying hand lens, but cannot be definitely
distinguished from perithecia or the young stages of the stylospores.
Stylospores are borne in conceptacles, which in their simplest form
resemble flasks with long drawn-out necks. Frequently, however,
they are much branched, and as they project from 1 to 2 mm. be-
yond the mycelium they form quite a conspicuous part of the
fungus. They are easily recognized with the unaided eye, and can
be seen with considerable distinctness with a hand lens. Perithecia
are black, spherical reproductive bodies closely resembling pycnidia,
from which they can not be distinguished with a hand lens. How-
ever, they are larger, being eighty micro millimeters in diameter.
Each perithecium contains several asci and each of these bears
eight ascospores. Some of the investigators who have studied
this disease have failed to find perithecia, and only twice has the
writer found them in his examination of material from Florida.

“The various reproductive bodies other than perithecia, partic-
ularly the conidia and stylospores, are developed in great abun-
dance.”

M. niessleanea Wint. is common on Rhododendron.

Several entomogenous fungi !”""!® have been found which by prey-
ing upon those insects which secrete honey dew, lessen the injury

THE FUNGI WHICH CAUSE PLANT DISEASE 195

from all sooty molds. Among these are the genera Aschersonia !”
and Spherostilbe.

Microthyriacez (p. 170)

Mycelium superficial, dark; perithecia superficial, separate,
shield-shaped, unappendaged, black, membranous to carbonous,
formed of radiating chains of cells; asci 4 to 8-spored, short; pa-
raphyses usually present.

A family of over twenty genera and more than three hundred
species, chiefly poorly understood.

Only two species have been noted as serious economic patho-
gens; Scolecopeltis zruginea Zimm. and Microthyrium coffe
both on coffee in Africa.

The genera of the Ascomycetes which remain to be treated,
and which are separated from those preceding by the possession
of an ostiole, are by some known under the name Pyrenomycetes.
Cf. p. 170. There are three orders, the Hypocreales, Dothidiales
and Spheriales.

Hypocreales (p. 124)

The chief character separating this order from other Pyrenomy-
cetes is the brighter color—yellow, purple, scarlet, red, etc.—and
the more tender texture of its perithecia,—soft, fleshy, cottony,
patellate or effused.

The perithecium also differs from that of the preceding orders in
the possession of a distinct opening, ostiole, for the exit of spores.

Perithecia globose to cylindric or flask-shaped, free on the sub-
stratum (rarely subepidermal) or united by a common matrix,
which varies from a cottony subiculum to a distinct fleshy stroma,
wall membranous or at least not truly carbonous; asci cylindric,
clavate or subovoid, mostly 4 to 8-spored but often becoming
16-spored by the separation of each original spore into two globose
or subglobose cells; spores simple or compound, hyaline or colored,
globose to filiform.

Conidia are usually produced freely, each genus usually possess-
ing at least one form of free-borne conidia, while in some genera
several different kinds of conidia are found. Pycnidia are rare.
Often the ascigerous stage is nearly suppressed and rare while
one or more of the conidial forms predominates.

196 THE FUNGI WHICH CAUSE PLANT DISEASE

Such form genera as Verticillium, Tubercularia, Sphacelia,
Spherostilbe and Isaria are connected with the Hypocreales.

The order includes some sixty genera, and over eight hundred
species. Of these only a half dozen genera contain important plant
parasites, another half dozen genera, parasites of less importance.
The rest are saprophytes, insect parasites, etc., of no economic
significance.

Opinion differs as to the characters which should be made the
basis for subdivision of this family, whether to throw main stress
upon the structure of the perithecium or upon the character of
the spores.

Following Lindau” the order contains a single family, Hypo-
creacez,”" which may be divided into six subfamilies. Accord-
ing to a more recent treatment of the American members of the
group by Seaver * '?° two families and four tribes are recognized.
Lindau’s tribes Hyponectriee, Hypomycetee, and Melanosporee
are united with a part of Nectriee under the last name while the
remaining genera, referred by Lindau to this tribe, constitute the
tribe Creonectree. These tribes constitute the family Nectriacex.
The remaining tribes, Hypocreee and Clavicipitee with about the
same limits constitute the family Hypocreacez.

Key To Tripes or Hypocreaceze

Perithecia at first sunken in the substratum,
later erumpent. ..................45 1. Hyponectriee.
Perithecia not sunken in the substratum; ‘i
stroma present or absent
Stroma cottony, never fleshy; perithecia
immersed in the stroma, or borne on
its surface. ...............0. 0.00. 2. Hypomycetee.
Stroma fleshy or wanting
Spores dark colored; perithecia free on
the substratum (in some species
of Melanospora with a cottony
stroma) scattered............... 3. Melanosporeee.
Spores hyaline, yellow or red
Perithecia without a stroma, or on a
fleshy stroma................. 4, Nectriex, p. 197.

THE FUNGI WHICH CAUSE PLANT DISEASE 197

Perithecia sunken in a fleshy stroma
Spores not filiform; perithecia half
or entirely sunken in the

stroma, and distinct from it.. 5. Hypocreee, p. 198.
Spores filiform; perithecia com-
pletely embedded in the
stroma and not clearly ‘dis-

tinct from it............... 6. Clavicipitez, p. 199.

The first tribe contains no parasitic genera while the second and
third contain but one each. Of the Hypomycetez, the genus
Hypomyces (p. 200) is set off from the others by its 2-celled hyaline
fusiform spores, and its cottony stroma. Of the Melanosporee
the genus Melanospora (p. 200) is distinguished by the long beaks
of its flask-shaped perithecia, which are brown rather than black,
and its brown 2-celled spores.

Keys To Tar Genera or Nectriee, Hypocreee anv Clavicipiteee
Trine IV. Nectriez (p. 196)

Conidiophores not of the Stilbum type
Spores elongate, 1-celled; perithecia free
on the substratum; stroma none
Spores not appendaged
Perithecia yellow or red
Asci cylindric; ostiole concolorous
with the perithecium. ....... 1. Nectriella.
Asci clavate-cylindric; _ostiole
darker than the perithecium.. 2. Thelocarpon.
Perithecia violet or blue. .......... 3. Lisiella.
Spores appendiculate. ..........:.... 4, Eleutheromyces.
Spores elongate, 2 to many-celled
Spores with cross walls only
Spores 2-celled
Asci 8-spored; often with 1-celled,
conidia formed in the ascus
Perithecium yellow or red
Spores hyaline.............. 5. Nectria, p. 201.
Spores brown. ............. 6. Neocosmospora, p. 205.
Perithecium blue or violet..... 7. Lisea.

198 THE FUNGI WHICH CAUSE PLANT DISEASE

Asci many-spored
Perithecium fleshy, ostiole ele-
Vateds..acenorewevisesceus 8. Metanectria.
Perithecium hard, ostiole sunken 9. Cyanocephalium.
Spores 2 to many-celled

Spores not appendiculate
Perithecium bright colored, not
|) (eee ea 10. Calonectria, p. 205.
Perithecium blue or violet..... 11. Gibberella, p. 206.

Spores appendiculate, 4-celled
Perithecia clavate, ostiole wart-

IKGy cagechs seis edo 12. Paranectria.
Perithecia flask-shaped, ostiole
CMON GALE a s)5 sie aes ea ee sie 13. Lecythium.

Spores muriform
Perithecium bright colored, not
DING ss ci:0 gcc eee aoe ag 14. Pleonectria, p. 207.
Perithecia dark colored or blue... 15. Pleogibberella.
Spores filiform

Perithecia fleshy, bright colored. . .... 16. Ophionectria, p. 207.
Perithecia horny, brown............. 17. Barya.
Conidiophores of the Stilbum type, stroma
wanting
Spores 2-celled. . 0.2... 2. eee eee eee 18. Spherostilbe, p. 207.
Spores 4-celled. . .............0.00005 19. Stilbonectria.
Spores muriform. ............-.....00- 20. Megalonectria.

Tripz V. Hypocreee (p. 197)

Stroma sunken in the substratum or grown
to it, usually free later

Spores l-celled. . .............00000 0s 21. Polystigma, p. 207.
Spores 2-celled. . .............. cece eee 22. Valsonectria, p. 208.
Spores several-celled by cross walls...... 23. Cesatiella.
Spores muriform :
Spores hyaline...................00. 24. Thyronectria.
Spores olive-brown. ................ 25. Mattirolia.
Stroma from the first separable from the
substratum
Spores l-celled.. ..............0.0000. 26. Selinia.

Spores 2-celled
Cells of the spores separating in the ascus

THE FUNGI WHICH CAUSE PLANT DISEASE

Stroma patellate or effuse..........
Stroma erect, simple or branched. . .
Cells of the spores not separating in the
ascus
Stroma patellate or effuse..........
Stroma erect, branched. ...........
Spores 3 to many-celled
Stroma bright or dark colored, not

conidia-bearing. ................ 31.
Stroma dark, green or black, with
conidia
Conidia of two kinds. ............. 32.
Secondary conidia absent.......... 33.
Spores muriform...................... 34.

Tribe VI. Clavicipitese (p.
Stroma effused
Stroma forming a sheath about the host.
Stroma flat, tuberculate, or disk-shaped
Stroma, not conidia-bearing
Stroma, thick, usually light colored..
Stroma thin, black................
Stroma with the inner portion conidia-

Stroma erect
Stroma small, saccate, membranous. . .. .
Stroma large, erect, with distinct sterile
and fertile portions, the latter often
knob-like
Stroma formed in the bodies of insects
and spiders, or in subterranean

Stroma formed in the inflorescence of
Glumacee, ctc., spores continuous
Stroma not growing from a sclero-
TUM es erat oi ea evade
Stroma growing from a sclerotium
after a period of rest
Asci preceded by conidia... .....
Asci preceded by smut-like chla- {
mydospores..............-

35.

38.

39.

40.

41.

42.
43.
44.

199

. Hypocrea, p. 209.
. Podocrea.

. Hypocreopsis.
. Corallomyces.

Broomella.

Loculistroma, p. 215.
Aciculosporium, p. 211.
Uleomyces.

197)

Epichloé, p. 210.

. Hypocrella.
. Dothiochloe, p. 210.

Echinodothis, p. 211.

Odmyces.

Cordyceps.

Balansia, p. 209.

Claviceps, p. 211.
Ustilaginoidea, p. 213.
Ustilaginoidella, p. 114.

200 THE FUNGI WHICH CAUSE PLANT DISEASE

Hypomyces Fries (p. 197)

Stroma an effused cottony subiculum, often of considerable
extent; perithecia numerous, usually thickly scattered and im-
mersed in the subiculum, rarely superficial; asci cylindric, 8-spored;°

, spores fusoid or fusiform,
usually apiculate, rarely
blunt, 2-celled, hyaline;
conidial phase variable.

This genus of some forty
. species contains but few

. saprophytes, the majority
being parasitic, chiefly on
the larger fungi. The genus
is of economic interest only
as affecting mushrooms,
though one species, H.
hyacinthi has been found
causing secondary infec-
tion in onions,” following
a bacterial trouble, and

Fic. 141.—Hypomyces ochraceus. B, peri- i 5
thecia; C, asci and spores; D, spores; E, co- another; H. solani Reinke

nidia; F, chlamydospores. After Tulasne. follows a similar disease

on potatoes. Chlamydospores and conidiospores develop, be-
longing to various form genera as Verticillium, Mycogone, Fuligo,
Diplocladium, Dictylium, Sepedonium, Blastotrichum.

Allied to this genus are probably Mycogone rosea and M. per-
niciosa, which are destructive enemies of mushroom culture.

Melanospora Corda (p. 197)

Perithecia superficial, without a stroma, globose-pyriform or
flask-shaped, with a long neck which is usually clothed at the
tip with a fringe of hairs, perithecia often hairy; asci broadly
clavate, 4 to 8-spored; spores 1-celled, brown to brownish-black.

The genus contains some forty species, mostly common
saprophytes.

M. damnosa (Sacc.) Lin. is serious on wheat and rye.12% 124

THE FUNGI WHICH CAUSE PLANT DISEASE 201

M. stysanophora Mat. is said to be an ascigerous stage of
Dematophora glomerata, cf. p. 230, so injurious to the grape.

Nectria Fries (p. 197)

Stroma absent or tubercular, fleshy, bright colored; perithecia
single, or gregarious, on or in the stroma or among cottony hyphe,
globose or ovate, walls fleshy, yellow, red or brown, smooth or
hairy; ostiole papillate or not; asci cylindric or clavate, 8-spored;
spores elongate blunt or pointed,
hyaline, rarely red, 2-celled, form-
ing conidia in the ascus; paraphyses
usually none.

As conidial stages occur the form
genera Cephalosporium, Tubercu-
laria, Fusarium, Spicaria, Fusidium
and Chetostroma. Much doubt
exists as to specific limitations, and
as to the life histories of the species. =
Some two hundred fifty species have 4,, 142-—Melanospora. K, peri-
been described. Several are cred- thecium; ZL, asci; M, spores. After
: P é a Lindau.
ited with causing serious: diseases,
most of them occurring as wound parasites and unable to effect
entrance into sound tissue. Other species are pure saprophytes
and harmless.

The genus Nectria is divided into seven sub-genera, which are
frequently given generic rank, as follows:

Key To SuBGENERA oF Nectria

Spores smooth
Perithecia smooth

Stroma fleshy...............0500005 1, Eunectria, p. 202.
Stroma a cottony subiculum......... 2. Hyphonectria.
Stroma usually absent; perithecia
SCATLERED: 2 os Se ead cae needs ea ee 3. Dialonectria, p. 205.
Perithecia hairy. ..............2000-5- 4. Lasionectria.
Perithecia scaly... ...........0--0 eee 5. Lepidonectria.
Spores tuberculate.............-22-0-00+ 6. Cosmonectria.

Spores appearing striated, golden brown... 7. Phaeonectria.

202 THE FUNGI WH’CH CAUSE PLANT DISEASE

The majority of economic species belong to the first subgenus.

Eunectria (p. 201)

N. cinnabarina (Tode) Fr.

Stroma erumpent, tubercular, at first pinkish or yellowish-red,
darker with age, 1-2 mm. high and broad; perithecia almost glo-
bose, the ostiole rather prominent, becoming slightly collapsed, at
first bright cinnabar-red, darker with age, granular, 375-400 »
in diameter; asci clavate, 50-90 x 7-12 u; spores mostly 2-seriate,
elliptic elongate, ends obtuse,
slightly curved, 12-20 x 46 4g;
paraphyses delicate.

Tubercularia vulgaris borne on
the stroma is the conidial stage.
Conidiophores aggregated into tu-
bercular masses each 50-100 u long;
conidia on short lateral branches,
elliptic, hyaline, 4-6 x 2 uy.

The closely septate delicate
hyphe grow rapidly through the
wood or bark, penetrating nearly
Fic. 143.—N. cinnabarina, perithe- every cell and turning the wood

bia ermitting spores Ae black and collecting to form stro-

Hartig. mata on or in the bark. These
stromata in fall or spring break through the epidermis and produce
warty, gray to pink, excrescences, which at first bear profuse
conidia both terminally and laterally on short stalks and later
dark-red ascigerous structures; though the latter are much less
common and are often absent. The fungus is said to be unable to
affect living cambium and cortex.

It is found saprophytically on many decayed woody plants that
have been frost killed, and parasitically on pear, Tilia, Ausculus,
China berry, Betula, Ribes, Acer, Carya, Morus, Prunus, Quercus,
Ulmus, etc. Mayer ' germinated spores on a cut branch; the
mycelium spread to and killed the main stem; tubercles appeared
and during the following year perithecia developed on these
tubercles. In America the species has attracted attention on the

currant ' 1% in which host the mycelium invades chiefly the

THE FUNGI WHICH CAUSE PLANT DISEASE 203

cambium. On this host, however, it is now said to be non-
parasitic.”

Durand,'6 culturing the conidial form on sterile currant stems,
observed the formation of tubercles with abundant conidia after
about fourteen days. On agar conidia were produced directly from
single hyphe without any stroma. Perithecia were found in the
field on the tubercles with the conidia in February.

N. ditissima Tul.

Stroma light colored; perithecia cespitose, densely and irregu-
larly clustered, or rarely scattered, ovate, ostiole prominent, bright
red, smooth or roughened; asci cylindric to clavate, 80-90 x 8-10 y;
spores fusoid, 12-16 x 4-5 uy.

The unicellular microconidia are followed by falcate, multi-
cellular, macroconidia (Fusidium candidum), which are borne on
pale stromatic cushions.

Common on dicotyledonous trees, especially beech, oak, hazel,
ash, alder, maple, lime, apple and dogwood, where it is usually a
wound parasite, particularly common after hail. It is especially
well known from Europe 18 ond has more recently attracted atten-
tion in America.

The mycelium does not usually advance more then one centi-
meter in each year. It is believed that it can travel within the
wood and break through the cambium and cortex at points some
distance from the place of original infection, thus producing new
spots. Very minute conidia produced in the bark aid in tissue de-
composition. White conidial (Fusidium) stromata appear near
the periphery of affected spots and here, too, in groups or scattered,
appear the deep red perithecia. ;

N. cucurbitula Sacc.

Perithecial clusters erumpent, often irregular in form, 1-2 mm.
in diameter; perithecia densely clustered, bright red, ovate, with
a prominent ostiole, rarely. collapsing; asci cylindric to clavate
75-100 x 6-8 mu; spores at first crowded and partially 2-seriate,
finally becoming 1-seriate, lying obliquely in the ascus, broad,
fusoid, rarely subelliptic, 14-16 x 5-7 u.

Its hosts are spruce, fir, pine and other conifers in Europe and
North America.

The fungus is usually a wound parasite, often following hail.

204 THE FUNGI WHICH CAUSE PLANT DISEASE

Germ tubes from ascospores or conidia enter the cortex and
develop a rich mycelium in the sieve tubes and soft host. This
advances most rapidly during the dormant period of the bast.

White or yellow stromata the size of a pin-
head appear and bear numerous conidia. Later
come the red perithecia whose ascospores ripen
in winter or spring.

N. ribis (Tode) Rab.
Fic. 144.—N. ipo- Cespitose, stroma compact; perithecia sub-

meee, a cluster . i F

of perithecia, globose, smooth; ostiole papillate; asci subclavate,

After Halsted. 90-100 x 15; spores elongate or fusoid, hyaline,
l-septate, 18-20 x 5-6 mm. On currant.

N. ipomee Hals.

Perithecia clustered, ovate, roughened, red; asci cylindric-
clavate; spores elliptic; conidial phase (Fusarium) appearing as a
white mold-like covering of the host; conidia several-celled, falcate.

Halsted }” inoculated sterilized egg-plant stems with the Nectria
spores and the Fusarium form developed, followed by the asci-
gerous stage. Ascospores in hanging drop were also seen to give
rise to the Fusarial stage. The Nectrias found upon egg-plant
and sweet potato, morphologically alike, were proved by cross
inoculations to be identical.

N. rousselliana Tul. and N. pandani Tul. are parasitic on Buxus
and Pandanus respectively,” the former with the conidial stage.
Volutella buxi.

N. solani Ren. & Bert. is said by Massee to be the ascigerous
form of Fusarium solani.™

Perithecia crowded on a stroma, minute, conic-globose, smooth,

blood-red; asci clavate; spores hyaline, 8-9 x

€

5 »; paraphyses slender, tips strongly clavate.
Conidia (=Fusarium solani) hyaline, 3 to
5-septate, fusiform, 15-40 x 5-8 yu, but very
variable, borne on erect, simple or branched Fic. 145.—N. ipo-
conidiophores. aa — Tater
N. coffeicola Zimm. is on cacao and vanilla; .
N. bainii Mas. N. amerunensis A. & Str. and N. diversispora
Petch. are reported parasitic on cacao! pods. The three latter

names are probably synonyms of the first.

THE FUNGI WHICH CAUSE PLANT DISEASE 205

N. vandz Wah. and N. goroshankiniana (Wah.) grow on cul-
tivated Vanda: N. theobrome Mass., probably identical with
N. striatospora Zimm., is found on cacao trunks as is also N. jun-
geri Henn.

N. bulbicola. Henn. is on orchids and N. gigantispora Zimm. on
Ficus.

Dialonectria (p. 201)

N. graminicola B. & B., the conidial stage of which is Fusarium
nivale is destructive to winter wheat and rye
in Europe.}*! °

Less known are N. bogoriensis Bern and
N. vanille Zimm. on vanilla; N. luteopilosa
Zimm. and N. fruticola Zimm. on coffee; 1° |\,
N. theobromicola Mass. on Theobroma.

Neocosmospora E. F. Smith was reported by
Smith? as the ascigerous form of Fusarium yy. 146.—N. ipo-
vasinfectum and consequently as the cause of eee So bene
many serious wilt diseases. Recent work by ofascospores. Af-
Higgins 1% 34 and by Butler ™* has shown ‘ Halsted
that in all probability there is no genetic connection between
these forms and that the fungus under discussion is merely a

harmless saprophyte.

Calonectria (p. 198)

Perithecia free, often closely gregarious, true stroma wanting
but perithecia often surrounded by a radiate, white mycelium
which may simulate a stroma; perithecia globose to ovate, red
or yellow; asci elongate, 8-spored; spores elongate, more than
2-celled. About sixty species.

C. pyrochroa (Desm.) Sacc., has been reported parasitic on
Platanus.”® Its conidial stage is Fusarium platani.

C. flavida Mass. is in the West Indies on cacao causing

canker.
C. cremea Zimm. with Spicaria colorans, Corymbomyces albus,

206 THE FUNGI WHICH CAUSE PLANT DISEASE

Clanostachys theobrome !’ probably as its conidial stages, is on
fruits and stems of cacao.

C. bahiensis Hem. reported in South America on cacao stems
is really an Anthostomella; C. gigaspora Mass.™ is found on
sugar-cane.

Gibberella Saccardo (p. 198)

Stromata tuberculate, more or less effused; perithecia cespitose
or occasionally scattered on or surrounding the stroma; asci clavate,
8-spored; spores fusoid, 4 to many-celled, hyaline; conidial phase

subpedicellate, bluish, papillate,
\
~~ \.
ZT 4-5 wu; mycelium effused, crus-
F. hordei, F. heterosporum, have been referred to this ascigerous
inoculation and culture is shown to be identical on wheat, clover,

a Fusarium.
Of the thirteen species but few are parasitic.
G. saubinetii (Durieu & Mont.) Sace. 1 1%
Perithecia gregarious, leathery membranous, verrucose, ovate,
200-300 x 170-220 yu; asci oblong
clavate, acuminate, 60-76 x 10-
12 4; spores one or obliquely
two-ranked, fusiform, curved or
straight, acute, 4-celled, 18-24 x
Pe inte cic one ee, Wille toons plored. “Co-
nidia (=Fusarium) solitary, or
clustered, fusiform, curved, acute or apiculate, 5-septate, hyaline,
24-40 x 5 p.

Many species of Fusarium, e. g., F. culmorum, F. avenaceum,
stage. Spherical stylospores are also reported.’

The mycelium and the conidial stages often coat the grains and
heads of cereals with red or pink. Perithecia are rare as shining
dark dots on the grains in the late season. The Fusarium stage
also is said to cause a clover and alfalfa disease and the fungus by
barley, rye, spelt, emmer, and oat. . It is carried from season to
season on infected seed and causes large loss of young plants.
Doubt as to the relationship of the Fusarial forms mentioned with
the ascigerous stages has been raised by the work of Appel and
Wollenweber. See also Fusarium (p. 646).

THE FUNGI WHICH CAUSE PLANT DISEASE 207

G. cerealis Pass., the cause of a serious wheat disease in Italy 14
mnay be identical with the last species.
G. moricola Ces. & d. Not. grows on Morus.

Pleonectria Saccardo (p. 198)

Perithecia cespitose or separate, globose, pale, papillate; asci
8-spored; spores many-septate, muriform, hyaline.

P. berolinensis Sacc., which occurs on various species of
wild and cultivated currants both in Europe and America has
been reported by Durand 6 as associated with a currant trouble
in New York.

P. coffeicola Zimm. attacks coffee.

Ophionectria Saccardo (p. 198)

Stroma globose, tubercular, depressed or none; perithecia su-
perficial, clustered or scattered; asci cylindric to clavate, 2 to
8-spored; spores 4 to many-celled, fusoid to subfiliform, hyaline
or subhyaline.

About fourteen species. O. coccicola E. & V. attacks scale in-
sects and is said also to cause gummosis of oranges.!4?_ O. foliicola
Zimm. is found on coffee.

Spherostilbe Tulasne (p. 198)

Stroma a slender stalk with a globose or conical head; perithecia
bright colored, membranous, globose, subglobose or ovate; asci
cylindric or subcylindric, 8-spored; spores 2-celled, elliptic or
subelliptic, hyaline. Conidial phase Stilbum, Atractium or Micro- -
cera.

Some twenty species. S. repens B. & Br. in India causes a
root disease of Hevea!“ and arrowroot.

S. flavida Mass.™ causes disease of coffee in tropical America.

Polystigma De Candolle (p. 198)

Stroma fleshy, effused, red or reddish-brown, growing on leaves;
perithecia sunken, only the ostiole being above the surface, thin,
leathery, hyaline; asci elongate, clavate, 8-spored; spores ellipsoid,
1-celled, hyaline. Three species.

208 THE FUNGI WHICH CAUSE PLANT DISEASE

P. ruba (Pers.) D. C. causes reddish spots on the leaves of
Prunus. Stroma at first bearing pycnidia
[- (Libertella rubra) with filiform hooked, con-
O} tinuous conidia. Perithecia produced on old
C leaves, bearing ellipsoid to elongate asci;
spores 10-13 x 6 u, smooth.

The invaded leaf ‘tissue is colored by the
mycelium which bears a reddish oil. Nu-
merous perithecia are immersed in the

6 diseased area and, opening to the surface,
extrude spores which seem incapable of in-
fecting. During winter the stroma darkens,

Fic. : 46<P. mitra, CDS hard and produces the perithecia and

D, asci; E, conidia. ascospores. Ascogonium and trichogyne-like

fax ay organs have been described.'**

P. ochraceum (Wahl.) Sacc. occurs on Prunus padus.

Valsonectria Spegazzini (p. 198)

Stroma thin, cushion-shaped, under the bark of the host; peri-
thecia similar to those of Valsa, sunken in the stroma, the beak
erumpent, red; asci cylindric, 8-
spored; spores 2-celled, hyaline or
light brown.

A genus of but three species which
differ from Valsa chiefly in their
red color. ee

V. parasitica (Murr.) Rehm.?”® 3?

Pustules numerous, erumpent, at ees
first yellow, changing to brown at pyc. 149.—Showing a pycnidium of
maturity; perithecia usually ten to Valsonectria and the manner in

© which the spores issue from it.
twenty in number, closely clustered, After Murrill.
flask-shaped, deeply embedded in the stroma in the inner bark,
scarcely visible to the unaided eye; necks long, slender, curved,
with thick black walls and rather prominent ostiola; asci oblong-
clavate, 45-50 x 9 u, 8-spored; spores usually biseriate, hyaline,
oblong, rounded at the ends, often slightly constricted, unisep-
tate, 9-10 x 4-5 uw. Summer spores very minute, 1 x 2-3 yn, pale-

THE FUNGI WHICH CAUSE PLANT DISEASE 209

yellowish, cylindrical, slightly curved, discharged in twisted threads
as in Cytospora.

This fungus, originally described as Diaporthe parasitica, is a
serious parasite on the chestnut. The mycelium grows through
the inner bark in all directions from the initial wound at which in-
fection occurred, eventually girdling the part. The wood is also
affected. The perithecia appear in abundance upon or in cracks
of the bark, extruding their spores in greenish to yellow threads.

Hypocrea Fries (p. 199)

Stroma subglobose to patellate, fleshy or subfleshy; perithecia
entirely immersed, subglobose to ovate, the necks slightly pro-
truding; asci cylindric, originally 8-spored, spores breaking each
into two so that the asci at maturity contain sixteen hyaline
spores. About one hundred ten species.

H. ceretriformis Berk. occurs on the bamboo in Tonkin;

H. sacchari on sugar cane.

Balansia Spegazzini (p. 199)14
Sclerotium composite, formed of the affected parts of the host

tate and capitate or sessile, pul-
vinate, obovate, discoid, or sepa-
rated from the sclerotium as
soon as the latter is mature, sur-
face slightly papillate from the
projecting ostiola of the im-
mersed scattered perithecia; asci
8-spored; paraphyses none. Co-
nidia, when known, an Ephelis
and preceding the stroma.

B. hypoxylon (Pk.) Atk. oc-
curs on various grasses, chiefly
in the southern United States. Fic. 150—B. hypoxylon, section of

. . : pseudosclerotium and one stroma
B. claviceps Speg. infests Setaria 2iGwing perithecia, stem, leaf ele-

and Pennisetum in tropical lands. | ments and an ascus. After Atkinson.
The remaining species, chiefly of warm regions, are mostly grass

inhabiting.

210 THE FUNGI WHICH CAUSE PLANT DISEASE

Dothichloe Atkinson (p. 199)!45

Stroma thin, hard when dry, black, especially the outer portion,
lighter within, effuse, pulvinate, disciform or armilla-form, partly
or entirely surrounding the host; perithecia crowded, confluent
with the stroma, but the thin walls of distinctive structure, im-
mersed, the apex projecting; asci cylindric, 8-spored; spores fili-
form, septate at maturity, and eventually
separating at the septa into short seg-
ments.

Like the preceding genus, both species
D. atramentosa (B. & C.) Atk. and D.
aristide Atk. are grass inhabitors of
warm regions of the United States. The
former is the commoner species with a
wider range of hosts.

Epichloe (Fries) Tul. (p. 199)

Stroma effused, subfleshy, at first pale,
becoming bright orange, sheathing the
host; perithecia immersed or with the
ostiola protruding; asci cylindric, 8-
spored; spores filiform, many-celled. Of
some nine species only one is important.

E. typhina (Pers.) Tul. Stroma ef-
fused, at first pale, becoming bright
f orange, forming sheaths 2-5 cm. long
Fig. 151.—Epichloe. A, habit around stems of various grasses, often

sein Gf asgus D, See destroying the inflorescence; perithecia

ee ca Bre- thickly scattered, partially or entirely im-

mersed in the stroma, soft, membranous,
concolorous with the stroma, the ostiole rather prominent; asci
very long; spores almost as long as the ascus, closely fasciculate,
multiseptate, about 2 » in diameter; conidia elliptic, hyaline,
4-5 x 3 uw, preceding the perithecia on the stroma.

Many grasses are affected, often to serious extent. The mycelium
shows first as a yellowish cobwebby growth surrounding the leaf
sheath and soon develops a conidial stroma. Later the stroma

THE FUNGI WHICH CAUSE PLANT DISEASE 211

turns to orange-color and the perithecia appear, forming a
layer.

Echinodothis Atkinson (p. 199) 56

Stromata subfleshy or corky, light-colored, pulvinate to sub-
globose or irregular in form, often constricted at the base, some-
times entirely surrounding the host, consisting of several layers of
different consistency; perithecia superficial, scattered, subcylindric,
sessile, giving an echinulate appearance to the stroma; asci cylin-
dric, 8-spored; spores linear, septate, at length separating at the
septa into short segments.

Two species, parasitic on grasses in the warmer parts of the
western hemisphere.

E. tuberiformis (Berk. & Rav.) Atk.3%

Stromata subglobose, 1 em. or more in diameter, entire, lobed,
or divided, seated upon the reed or upon the leaf-sheath and -fas-
tened by a whitish mycelium consisting of radiating threads which
are sometimes tinged yellowish-brown; substance leathery or corky,
consisting of three layers, an inner layer white to pinkish, an inter-
mediate layer light ochraceous and an outer layer cinnamon;
stroma, externally dark brownish becoming black; conidiophores
needle-shaped; conidia ovoid to fusoid, 3-4 x 7-10 uw; perithecia
entirely superficial in small clusters or evenly distributed over
the exposed surface of the stroma, subconic in form, giving the
whole stroma a spiny appearance, clothed except the apex with a
dense covering of minute threads which are at first. whitish, be-
coming cinnamon colored, the naked apex becoming black, about
0.3 x 1 mm.; asci cylindric, with a swelling at the apex, very large,
475-750 x 14-20 yu; spores nearly as long as the ascus, hyaline or
slightly yellowish, many-septate, the joints 15 x 4-5 un.

On Arundinaria in the Southern States.

Asciculosporium take Miy.'“* forms witches’ brooms on bamboo
in Japan. It is closely related to Dusiella and Epichloe.

Claviceps Tulasne (p. 199)

Sclerotium formed within the hypertrophied tissues of the
ovary of the host, succeeding the conidial stage which is a
Sphacelia; stroma erect, with a long sterile base and a fertile,

212 THE FUNGI WHICH CAUSE PLANT DISEASE
usually knot-like head; perithecia closely scattered, sunken in
the stroma with only the ostiole protruding, flask-shaped, the
walls scarcely distinguishable from the stroma; asci cylindric,

Fic. 152.—C. purpurea. D, Sphacelia stage; E, germinated sclerotia; G, sec-
nen of stroma; H, section of a perithecium; J, ascus with spores. After
asne.

8-spored; spores hyaline, continuous. Some twelve or fifteen
species are recorded all affecting the ovaries of the Graminez.

C. purpurea (Fr.) Tul.!”

Sclerotium elongate, more or less curved, and resembling a much
enlarged grain, after a period of rest producing few or many,
clustered or scattered stromata which are 0.5-1.5 cm. high; spore

THE FUNGI WHICH CAUSE PLANT DISEASE 213

60-70 u. long. Conidia (=Sphacelia segetum) produced on the
grain before the sclerotium is formed, conidiophores short, cylin-
dric, arranged in a compact palisade, bearing small, oval, hyaline,
1-celled conidia. Hosts, rye, wheat, oats and numerous other
grasses.

Infection of the ovary at blooming time is followed by complete
possession and consumption of the ovarial tissue by the mycelium,
and by considerable development of stroma beyond the ovary.
On the external much-folded part of this stroma, particularly at
its distal end, are borne layers of conidiophores and numerous
conidia and a sweet fluid is exuded. The conidia, carried by in-
sects, spread summer infection. Later the stroma, losing a large
- part of the distal region, rounds off to a definite sclerotium, smooth,
firm, blue to black in color, and several times larger than the
normal grain of the host plant.

After a period of rest, usually lasting till the following season,
the sclerotium gives rise to several stalked, capitate, perithecial
stromata. The perithecia are arranged around peripherally, the
ostioles protruding and giving the head a rough appearance. The
sclerotium constitutes the ergot of pharmacy and contains a
powerful alkaloid capable of causing animal disease if eaten.

This species appears to be differentiated into a number of
biologic races.148

C. microcephala (Wal.) Tul. infects numerous grasses both in
Europe and America, being especially destructive to blue grass.

Two species C. paspali S. & H. and C. rolfsii S. & H. have been
reported on Paspalum.'

Ustilaginoidea Brefeld (p. 199)!©

Sclerotium formed in the grain of the host, resembling super-
ficially a smut sorus, in the center composed of closely interwoven
hyphe, externally the hyphe are parallel, radiating towards the
periphery and bearing echinulate, globose, greenish conidia; stroma
with a long sterile stem and a fertile head; perithecia immersed
in the stroma as in Claviceps; asci and spores also as in Claviceps.

Two species are known, one on Setaria which produces an
ascigerous stage, the other on rice, the ascigerous stage of which

214 THE FUNGI WHICH CAUSE PLANT DISEASE

is not known but which is placed in this genus on account of the
similarity of its conidial stage with that of the other species.
U. virens (Cke.) Tak. Ascigerous stage unknown, sclerotia spher-
ical, about 5 mm. in diameter; conidia spherical, at first smooth-
walled, hyaline, at maturity
BS =, echinulate and olive green,
9 , ae 4-6 mu.
ey The short thick walled
“2 hyphe of the interior of the
sclerotium are closely in-
ae ee F . terwoven to a false tissue,
Fic. 153.—U. virens; a, spores germinated in ‘
water; b, germinated in bouillon. After toward the periphery they
pc become parallel and are di-
rected radially. Here a yellow layer is produced and spores are
formed laterally on the hyphez. When mature the spores are in
mass dark olive-green and form an outer green layer on the
sclerotium. The spores germinate in water, producing a vegeta-
tive mycelium which bears secondary spores and somewhat re-
sembles the mycelium of the Ustilaginales.4*! Successful inocula-
‘tions have not been made.

Ustilaginoidella Essed (p. 199)

This is a genus -erected by Essed ? to receive the species
U. muszperda, which he regards as the cause of the “Panama
disease” of bananas, at least as it occurs in Suriname.

Sclerotia similar to those of Ustilaginoidea are found; chlamyd-
Ospores and conidia obtain, among the latter are some of marked
Fusarium type; others are in pycnidia.

U. cedipigera Essed is also described by Essed *? as the cause
of another less important banana disease in Suriname and Colum-
bia; a disease accompanied by hypertrophy of the base of the
stem and leading to the common name “bigie foote.” This
fungus differs from the last in its 1 to 2 to 3-celled conidia.

U. graminicola Essed causes a rice disease. This species
differs but Slightly from the two preceding. Chlamydospores
smaller, conidia 1 to 5-celled.

THE FUNGI WHICH CAUSE PLANT DISEASE 215

Loculistroma Patterson & Charles!®? (p. 199)

Stromata upright, sessile, at the nodes of the host, fleshy, soft,
green or black, containing conidial chambers in which are pro-
duced hyaline filiform conidia and on the outer surface of which
are borne Cladosporium-like conidia; perithecia scattered, partly
immersed, ostiolate; asci clavate, cylindric, 8-spored; spores fusi-
form, 3 to many-septate, olivaceous, biseptate; paraphyses none.
There is only one species known.

L. bambuse. P. & C.1%2

Stromata 1 cm. long by 2 mm. in diameter; perithecia almost
spherical, 125 x 100 yw; asci 45-50 x 9-10 wu; spores 22 x 4. 5-5 pw ‘
primary conidia 14-16 x 0.75-1 u; borne in chambers on basidia,
8 x 0.5 w; secondary conidia external, 1 to 3-celled, borne on
external olivaceous hyphz.

It causes a witches’ broom of bamboo (Phyllostachys sp.), in
China. Infection probably occurs in the terminal node. The
fully developed sclerotia-like structures, resembling those of
Claviceps, are dark green to black when mature, and consist of
a central hyaline sclerotial tissue in which are many round
conidial chambers. Perithecia develop from the peripheral
layer.

Dothidiales (p. 124)

- There is only one family the Dothidiacee.

Mycelium developed in the substratum, septate, at length form-
ing a thick, dense, very dark stroma in which the perithecia are
sunken and with which their walls are completely fused, rarely
partly free; asci borne from the base of the perithecium; paraphyses
present or none.

The Dothidiacew contain some four hundred species and more
than twenty-four genera. They differ from the last order in their
firm black sclerotium-like stromata which are usually pale to white
within. The perithecia are usually grouped together in great num-
bers in the external layer of the stroma, sunken in its undiffer-
entiated body. Conidia of various forms are present.

216 THE FUNGI WHICH CAUSE PLANT DISEASE

Key to GENERA oF Dothidiacee

Stromata at first sunken later more or less
free
Perithecia standing free on the stroma;
spores at maturity, 4-celled, dark
Perithecia almost completely embedded
in the stroma
Stromata variable, more or less irreg-
ular in outline but never elongate
Spores 1-celled i
Spores hyaline
Asci typically borne at the
base of the perithecium
Asci 8-spored
Spores ellipsoid
Perithecia few. .......
Perithecia numerous. .
Spores filiform..........
Asci many-spored.........
Asci borne laterally at the
equator of the perithe-
cium, spores ellipsoid...
Spores brown... ..............
Spores 2-celled
Spores hyaline
Spores ovate. ..............
Spores needle-like...........
Spores colored
Cells of the spore similar. . . .
Cells of the spore dissimilar. .
Spores several-celled
Spores with cross walls only
Spores hyaline, 4-celled. .....
Spores colored, multicellular
Spores muriform
Spores hyaline..............
Spores colored. .............
Stromata elongate, linear or lanceo-
late

1.

14.
15.

Montagnella.

. Mazzantia.

. Bagnisiella.

. Ophiodothis.

. Myriogenospora.

. Diachora, p. 217.
. Auerswaldia.

. Plowrightia, p. 217.
. Rosenscheldia.
. Rousscella.

. Dothidea, p. 220.

. Darwiniella.
. Homostegia.

Curreyella.
Curreya.

THE FUNGI WHICH CAUSE PLANT DISEASE 217

Spores hyaline
Spores I-celled.. ............. 16.
Spores 2-celled............... 17.

Spores 4 to 8-celled, fusiform... 18.

Spores colored, multicellular, fusi-

SOTM Lato ear caens see oes oe 19.

Stromata sunken, permanently united to
the epidermis and substratum

Spores I-celled. . 2. ........... 00.0008 20.

Spores 2-celled

Spores of similar cells............... 21.
Spores of dissimilar cells............. 22.
Stromata from the first superficial
Stromata encrusted, widely spreading... 23.
Stromata cushion-shaped, limited....... 24,

Scirrhiella.
Scirrhia.
Monographus.

Rhopographus.

Phyllachora, p. 220.

Dothidella, p. 221.
Munkiella.

Hyalodothis.
Schweinitziella.

Of these genera only five are of interest as plant pathogens.

The majority contain only saprophytes.

Diachora Miiller (p. 216)

The genus is easily recognized by its peculiarity of bearing asci

only as an equatorial band instead of
on the floor of the perithecia, a char-
acter unique among the Pyrenomy-
cetes.

D. onobrychidis (D. C.) Mull. is
reported as causing black spots on
leaves of sainfoin and Lathyrus in
Europe.

Plowrightia Saccardo (p. 216)

sae $ F al
Stromata formed within the tissues yy, 154.—D. onobrychidis. E, co-

- nidial stage; F, ascocarp and asci.
of the host plant, erumpent, tuber pomerith

cular or cushion-shaped, depressed or

elevated, smooth, later frequently wrinkled, white within; asci
cylindric, 8-spored; spores ovate, 2-celled, hyaline or light green;
conidial forms Cladosporium, Dematium, etc.

218 THE FUNGI WHICH CAUSE PLANT DISEASE

Some twenty species are known. They are distinguished from
Dothidia by the hyaline spores.

Fic. 155.—P. morbosa. 6, magnified section of a knot showing the
perithecia; c, conidiophores and conidia; d, section of a peri-
thecium showing numerous asci, one of which is shown more highly
magnified at e; f, several of the two-celled ascospores germinating
in water. After Longyear.

P. morbosa (Schw.) Sace. 15157, 266
Stromata elongate, cushion-shaped, rarely tubercular, up to 2 or

THE FUNGI WHICH CAUSE PLANT DISEASE 219

3 dm. long; perithecia scattered, often entirely suppressed; asci
about 120 » long; spores variously arranged in the ascus, 16-20 x
8-10 yu, ovate, the cells usually unequal ; paraphyses filiform.

Conidia (=Cladosporium sp.) pro-
duced upon greenish areas on the young
stromata; conidiophores erect, flexuose,
septate, simple, 40-60 x 4-5 u; conidia
borne singly at the apex of the conidio-
phore, obovate, unicellular, light brown,
about 6-8 x 2-5 un.

Hosts: Cultivated sour cherry and
plum, wild red and yellow plum,
Chickasaw plum, choke cherry, wild

Found only in America.

The mycelium invades the cambium crotch. After Lodeman.
of twigs and from it grows outward into the bark region causing
the bark elements to overgrow and the twig to swell slightly dur-
ing the first summer. With the renewed growth of the following
spring the swelling proceeds rapidly. During May to June the
mycelium ruptures the bark which is soon lost and a dense fun-
gous pseudoparenchyma is formed. From this the conidiophores
appear, forming a velvety growth of olivaceous color. At this
period the knot consists largely of a fungous stroma with an ad-
mixture of bark elements and even some wood cells.

Later in the season conidiophores cease to form and the knot
turns to a black hard stroma. Perithecia now become easily
visible in this black stroma and in January or later the asci mature.
Farlow has described ‘“stylospores” (a form named Hendersonula
morbosa by Saccardo the connection of which to P. morbosa is
in some doubt) and spermogonia and pycnidia. Humphrey '°¢
from ascospores, in artificial media, raised a pycnidial form which
seemed to be distinct from any of these. That the fungus is
the actual cause of the black knot was first demonstrated by
Farlow 4 in 1876, though the fungus was described as early as
1821 by Schweintiz.1

Lodeman !** considered that infection is favored by cracks
existing at crotches of the tree. Fig. 156.

220 THE FUNGI WHICH CAUSE PLANT DISEASE

P. ribesia (Pers.) Sacc. is found in Ribes twigs and

P. virgultorum (Fr.) Sacc. on birch. Both are European.

P. agaves occurs on the maguey.”?

Dothidea Fries. distinguished from Plowrightia by its colored
spores, contains some twenty-five species which occur on twigs of
Sambucus, Rosa, Buxus, Betula, Juniperus, Quercus and many
other woody plants.

D. ros@ Fries. is common as the supposed cause of a rose tumor.

D. noxia Ruhl. causes an oak twig disease in Germany.”

Phyllachora Nitschke (p. 217)

Stroma sunken, united to the parenchyma and epidermis of
the host leaf, rarely erumpent, encrusted, usually jet-black; peri-
thecia sunken in the stroma, rather numerous,
with more or less distinct ostioles; asci cylindric,
8-spored; spores ellipsoid or ovate, 1-celled,
hyaline or yellowish; paraphyses present.

More than two hundred species, largely
tropical, are known on a wide range of hosts.
All are leaf parasites.

P. graminis (Pers.) Fcl. Stromata variable in
size and form, causing conspicuous black spots
on leaves of the host; perithecia immersed, os-
tiolate; asci short-pedicillate, cylindric, 70-80 x
7-8 ; spores obliquely uniseriate, ovoid, hya-
line, 8-12 x 4-5 yw; paraphyses filiform. No
- conidia are known.

1a. 157.—P. gram- ,

inis. B, stromain This fungus occurs on many grasses and

see morc Aat® sedges with slight injury to them.

Winter. P. pomigena (Schw.) Sacc. produces black
spots, scarcely ever above 5 mm. in diameter, on apples, especially
the Newton Pippin, in the eastern United States. Little is
known of the species.

P. trifolii (Pers.) Fel. causes small black spots 1 mm. or less
in diameter on clover leaves; asci cylindric; spores uniseriate, oval,
hyaline, 8-10 x 5-6 p.

Conidia (=Polythrincium trifolii) precede the asci on the stro-

THE FUNGI WHICH CAUSE PLANT DISEASE 221

mata; conidiophores wavy or zigzag, erect, simple, black, conidia
obovate, 1-septate, constricted, pale olivaceous, 20-24 x 9-10 py.

The conidial form is very common on various species of clover
in Europe and America while the ascosporic stage is mentioned
only by Cooke and Clevenger.'®

P. cynodontis (Sacc.) Niess. on Cynodon, P. poz (Fel.) Sacc.
on Poa and P. dapazioides (Desm.) Nke. on
Box and Rhododendron are European.

P. makrospora Zimm. occurs on Durio zibel-
linus;

P. sorghi v. Héh. on Sorghum vulgare.!®?

Dothidella Spegazzini differs from Phyllachora
in having 2-celled hyaline spores, the cells un- x
equal in size. There are over fifty species of a ae Road
the genus. Epiphyllous, subrotund confluent, $Po7es After
convex, grayish-black, on white spots; ostiole
granular; asci cylindric, short-stipitate, 60-70 x 8 u; spores ob-
long, ovate oblong, hyaline, 10-15 x 5 u. D. ulmi Duv.*” Co-
nidia=Septoria ulmi and Piggatia astroidea. On elm in Europe
and America. Other species are D. thoracella (Rostr.) Sacc. on
Sedum, in Europe, D. betulina (Fries) Sacc. on Betula in Europe
and Asia.

Spheriales (p. 124)

Mycelium chiefly confined to the substratum; perithecia vari-
able, usually globose, with a.more or less elongated ostiole, hairy
or smooth, free on the substratum, more or less deeply sunken, or
borne on or sunken in a stroma; asci borne basally, variable in
size, opening by a pore; spores variable, globose, ovate to elongate
or filiform, hyaline or colored; paraphyses usually present; conidial
forms various.

The stromata may vary from a delicate hyphal weft to a firm
crustaceous structure. The pyenidia are mostly carbonous, black
and brittle. Conidia of many forms are present and often con-
stitute the only truly parasitic form of the fungus; the asci-
gerous form developing only after the death of the part of the
host involved.

222 THE FUNGI WHICH CAUSE PLANT DISEASE

The order is very large, embracing according to Engler & Prantl
some eighteen families and over six thousand species.

Key to Famiuies or Sphariales

Perithecia free, either without a stroma,
partly seated in a loose mass of myce-
lium, or sessile above an imperfect
stroma

Walls of the perithecia thin and mem-
branous; asci soon disappearing
Perithecia always superficial, with
copious tufts of hair at the mouth
Perithecia usually sunken, with only
short hairs about the mouth.....
Walls of the perithecia coriaceous or car-
bonous
Perithecia either entirely free, or with
the base slightly sunken in the
substratum or stromatic layer
Stroma wanting or only thread-like
or tomentose
Mouths of the perithecia mostly in
the form of short papille. . . .
Mouths of the perithecia-more or
less elongate, often hair-like. .
Stroma present
Stromata mostly well developed,
indefinite; perithecia in close
irregular masses, never flask-
like of funnel-like at the apex
Stromata small, sharp-bordered;
perithecia in rows or in regu-
lar rounded masses, flask-
shaped with funnel-shaped

Perithecia more or less deeply sunken
in the substratum at base, free
above

Mouths of the perithecia circular in
outline.

. Chetomiacee.

. Sordariacee, p. 224.

. Spheriacee, p. 225.

. Ceratostomatacee,

p. 232.

. Cucurbitariaces, p. 234.

. Coryneliacee.

. Amphispheriacee.

THE FUNGI WHICH CAUSE PLANT DISEASE 223

Mouths of the perithecia laterally
compressed... ................
Perithecia without a stroma, and sunken in
the substratum, or with a stroma
Stromata none; perithecia rarely united
above by a black tissue (clypeus)
Asci not thickened at the apex, mostly
projecting at maturity
Walls of the perithecium thin, cori-
aceous; mouth mostly short or
plane
Asci clinging together in fascicles,
without paraphyses. ........
Asci not fasciculate; with para-

Walls of the perithecia carbonous or
thick coriaceous; spores large,
mostly enveloped by gelatine. .

Asci usually thickened apically, open-
ing by a pore; perithecia usually
beaked

Perithecia without a clypeus. ......

Perithecia with a clypeus. .........

Perithecia firmly imbedded in a stroma,
the mouths only projecting, or becom-
ing free by the breaking away of the
outer stromatic layers

Stromata fused with the substratum

Conidia produced in pycnidia. .....

Conidia developed from a flattened
SUTIACE He eee ae aes

Stromata formed almost wholly of hard-
ened fungal hyphe ;

Spores small, cylindric, 1-celled,
mostly curved, hyaline or yel-
lowish-brown...............-.

Spores rather large, 1 to many-celled,
hyaline or brown, conidia mostly
in cavities in the stroma. ......

Spores -celled, rarely 2-celled,
blackish-brown. Conidia devel-

8.

10.

11.

12.
13.

14.

15.

16.

17.

Lophiostomatacee.

[p. 235.

. Mycospherellacee,

Pleosporacee, p. 250.

Massariacee, p. 262.

Gnomoniacee, p. 263.
Clypeospheriacee,
p. 276.

Valsacee, p. 277.

Melanconidacee,
p. 279.

Diatrypacez, p. 281.

Melogrammatacee,
p. 282.

224 THE FUNGI WHICH CAUSE PLANT DISEASE

oped on the upper surface of
the young stroma............ 18. Xylariacez, p. 284.

Families Nos. 1, 6, 7, 8, 17 are saprophytes on plants and
animals.

Sordariacee (p. 222)

Perithecia superficial or deeply sunken in the substratum, often
erumpent at maturity, thin and membranous to coriaceous, slightly
transparent to black and opaque; stroma usually absent, if present
the perithecia immersed in it with projecting papilliform beaks;
asci usually very delicate, cylindric, 8-spored; spores usually

dark-colored; paraphyses abundant.
A small order, chiefly dung inhabiting.

Key to Genera or Sordariacee

Spores continuous
Without a stroma

Neck of the perithecium hairy. ..... 1. Sordaria.
Neck of the perithecium with black
BPWES 2 decdare d 29 capri emacs 2. Acanthorhynchus, p. 224.
With a stroma... ............-. ee eee 3. Hypocopra.
Spores 2 or more celled

Spores 2-celled

Spores hyaline.................005 4. Bovilla.

Spores dark-brown. ............05. 5. Delitschia.
Spores 4 to many-celled

Stroma absent..............-2006- 6. Sporormia.

Stroma present. .............0005- 7. Sporormiella.
Spores muriform; stroma present. . ... 8. Pleophragmia.

Acanthorhynchus Shear 163

Perithecia scattered, submembranous, buried, beaked, the beak
with non-septate spines; asci opening by an apical pore; paraphyses
present, septate; spores continuous, brownish-yellow.

There is a single species, A. vaccinii Sh.

Amphigenous: perithecia subglobose to flask-shaped, scarcely
erumpent, 120-200 u in diameter, neck stout, exserted, '/,—"/. the
length of the perithecium; spines 50-70 x 8-9 yu; asci subelliptic
to somewhat clavate, subsessile, 120-155 x 24-44 yu; spores oblong-

THE FUNGI WHICH CAUSE PLANT DISEASE 225

elliptic, surrounded by a mucilaginous layer, 24-32 x 12-18 u;
paraphyses exceeding the asci.

The mycelium produces rot of cranberries, also leaf spots, but
the fructification of the fungus is rarely found in nature except on

Fic. 160. — Acan-
thorhynchus; a
germinating as-

Z ey, = cospore bearing

: : the peculiar

Fia. 159.—A single perithecium appressorium,

of A. vaccinii taken from a 17, view from

pure culture on corn meal. above. After
After Shear. Shear.

old fallen leaves. In culture, however, it produces abundant peri-
thecia. When on the leaf the perithecia are subepidermal and
are sparsely scattered over the lower surface. No conidial or
pycnidial form is known. Remarkable appressoria are produced
by the germ tubes from the spores, Fig. 160.

Spheriacee (p. 222)

Perithecia single or clustered, free or with a false stroma in
which they are more or less sunken; walls leathery, horny or woody;
ostiole rarely elongate, usually papillate; spores frequently ap-
pendaged.

The family is distinguished by its free perithecia with papillate
ostioles. It contains about seven hundred species.

Key to Genera or Spheriacere

Perithecia hairy above, rarely smooth above
and hairy beneath
Spores 1 or 2-celled
Perithecia thin, cuticulate or leathery
Spores 1-celled; asci apically thick-
ONO: wf ssaies wen deweves Ses kes 1. Niesslia.

226
Spores 2-celled; asci not apically
thickened. ...........-..-.-..
Perithecia thick, leathery or carbon-
ous

Spores hyaline, sometimes becoming
brown, 1 or 2-celled
Spores ellipsoid. ................
Spores cylindric, bent. ..........
Spores dark colored, 2-celled. ......
Spores more than 2-celled
Perithecia thin, leathery or cuticula-

Perithecia thick, carbonous or woody

Spores 4-celled, the two middle cells

brown, the end cells hyaline... .

Spores many-celled, concolorous,
hyaline or brown

Spores spindle-form.............

Spores elongate-cylindric. .......

Perithecia smooth

Perithecia tuberculate or irregularly
thickened
Spores ellipsoid, 2 to many-celled,
hyaline. .............0...0000 00
Spores spindle-form, 4 to 11-celled,
Wyaline ss 4 oc ss ehh dea veseers

Spores muriform, dark..............
Perithecia not tuberculate
Spores 1-celled, dark
Spores with hyaline appendages on
each end; perithecia thick, leath-
CNY aradlenaiicra eases
Spores unappendaged, perithecia
carbonous ................0..
Spores 2 to many-celled
Perithecia thin, leathery; spores 2-

Perithecia thick, leathery or car-
bonous, brittle
Spores ellipsoid
Spores 2-celled

2.

10.

11.
12.

13.

14.

15.

THE FUNGI WHICH CAUSE PLANT DISEASE

Coleroa, p. 227.

. Trichospheria, p. 228.
. Leptospora.
. Neopeckia.

. Acanthostigma, p. 229.

. Chetospheria.

. Herpotrichia, p. 229.
. Lasiospheria.

Bertia.

Stuartella.
Crotonocarpia.

Bombardia.

Rosellinia, p. 230.

Lizonia.

THE FUNGI WHICH CAUSE PLANT DISEASE 227

Spores hyaline, sometimes be-

coming brown.......... 16. Melanopsamma.
Spores hyaline to green... ... 17. Thaxteria.
Spores dark-colored......... 18. Sorothelia.

Spores 3 to many-celled
Spores hyaline.............. 19. Zignoélla.
Spores dark-colored......... 20. Melanomma.
Spores elongate, spindle-form, hya-

line, many-celled. .......... 21. Bombardiastrum.

Coleroa Fries (p. 226)

Perithecia free, small, globose, flask-shaped ; asci 8-spored; spores

D

Fic. 161.—C. chetomium. C, perithecia; D, asci.
After Lindau and Winter.
ovate, 2-celled, hyaline, green or golden-brown; paraphyses poorly
developed.

Conidia= Exosporium.

This genus, of some thirteen species all of which are parasitic,
is quite similar to Venturia. The chief economic species are C.
chetomium (Kze.) Rab. (Conidia=Exosporium rubinus) on Rubus
in Europe and C. sacchari v. B. d H., on sugar cane in Java.'®4

228 THE FUNGI WHICH CAUSE PLANT DISEASE

Trichosphzria Fuckel (p. 226)

Perithecia usually free, globose, woody or carbonous, hairy,
ostiole flat or papillate; asci-cylindric, 8-spored; spores 1 to 2-celled,
hyaline; paraphyses present.

There are some forty species, mainly saprophytes.

T. sacchari Mass.}®» 16

Perithecia broadly ovate, dark-brown, beset with brown hairs;
spores elongate-ellipsoid, 1-celled; the conidial forms are various

Fic. 162.—Trichospheria. E, habit sketch; G, conidial
stage. After Lindau, Winter and Brefeld.

and their genetic connection is by no means certain. (1) (=Conio-
thyrium megalospora) Pycnidia 1-3, on a dark-colored, parenchy-
matous stroma; conidia elongate, straight or curved, brownish,
12 x 5 p, (2) The macroconidia (=Thielaviopsis ethaceticus)
see p. 596, are often found forming intensely black, velvety
layers lining cracks and cavities in diseased canes. (3) Micro-
conidia produced on the surface in Oidium-like chains. Their
connection with this fungus is disputed and uncertain.”
It is a sugar cane parasite.

THE FUNGI WHICH CAUSE PLANT DISEASE 229

Acanthostigma de Notaris (p. 226)

Perithecia free, globose or ovate, very small; walls leathery,
black, beset with stiff bristles, ostiole
short; asci usually cylindric, rarely
ovate, 8-spored ; spores spindle-shaped,
multicellular by cross walls, hyaline;
paraphyses few or none.

There are some thirty species,
mostly saprophytes.

A. parasiticum (Hart.) Sacc.167-168

Perithecia globose, minute, with
rigid divergent hairs, 0.1-0.25 mm.
in diameter; asci 50 y» long, early
disappearing; spores fusoid, straight
or curved, smoky, 15-20 y, continuous
or 2 to 3-septate.

Common on leaves of Abies, Tsuga
and other conifers in Europe and
America. The hyaline mycelium Fic. 163.—Perithecium of A. Tri-
grows on the lower sides of branches © chospheria parasiticum, show-
and onto the leaves killing them inf, csticle, bristles, asci, pata:
and matting them to the branches. artie.

The mycelial cushions later turn brownish and eventually very
small perithecia form on them.

Herpotrichia Fuckel (p. 226)

Perithecia superficial, globose or subglobose, texture firm,
coriaceous to subcarbonous, hairy or smooth, ostiole papillate
or not; asci oblong to clavate; spores fusiform, 2 or many-celled,
hyaline or brown; paraphyses none.

The species, numbering about twenty-five and growing on
woody plants, are mostly saprophytes.

H. nigra Hart.’

Mycelium dark-brown, widely spreading, haustoria slender,
lighter in color; perithecia globose, dark, 0.3 mm. in diameter;
asci elongate, 76-100 x 12 u; spores constricted, 1-3 septate.

230 THE FUNGI WHICH CAUSE PLANT DISEASE

Common in Europe on branches of Larix, Abies, Juniperus,
spruce and pine, doing great damage. The dark-brown mycelium
grows over the plant, killing and matting the leaves.

Rosellinia Cesati & de Notaris (p. 226)

Perithecia superficial, but often with the bases more or less
sunken in the substratum, coriaceous or car-
bonous; brittle, spherical or ovate, bristly or
not; asci cylindric, 8-spored; spores elliptic,
oblong or fusiform, 1-celled, brown or black;
paraphyses fusiform. Conidia of the type of
Coremium, Sporotrichum, etc.

In most cases the active parasitic stage
occurs on roots and consists of a vigorous
white mycelium, which remains for a long time
Ro aaa cael sterile, developing large branching and inter-

C, spore. After lacing rhizomorphs (Dematophora) which later

Wes become brown. These resemble somewhat, but
are distinguishable from, the rhizomorphs of Armillaria mellea;
again, they are Rhizoctonia-like.

There are over one hundred seventy species, mostly saprophytic.

R. necatrix (Hart.) Berl. 17

A destructive fungus, long known as Dematophora necatrix,
possesses a white mycelium which invades the small roots, thence
passes to larger ones, extending in trees through the cambium
and wood to the trunk, occasionally rupturing the bark and pro-
ducing white floccose tufts. Sclerotia of one or more kinds are
produced in the bark and often give rise to conidia on tufted conidi-
ophores in a Coremium-like layer (Fig. 165). The mycelium,
when old, turns brown and produces large branching, interlacing
rhizomophic strands which spread to the soil, or wind about the
roots.

In some instances the connection of the ascigerous with the
sterile or conidial stages is well established; in others the asci
have been found but rarely and the evidence of genetic connection
is not complete. It is probable that some fungi reported as Dema-
tophora do not in reality belong to Rosellinia.

The fungus attacks nearly all kinds of plants.

THE FUNGI WHICH CAUSE PLANT DISEASE 231

Perithecia were found by Viala”? and by Prillieux ”? on old
wood, long dead from such attack. These belong to the genus
Rosellinia and are believed to present the ascigerous form of Dema-
tophora necatrix. Similar claims of relationship of this fungus to
several other genera have
been made and its actual
position cannot be consid-
ered as established with
certainty.

R. massinkii Sace.

Perithecia sparse, globose
or depressed, carbonous,
165 yw; asci cylindric, 54 x
8 w; spores dark-brown, el-
liptic, 1-rowed, 10 x 5 p.

It is reported by Halsted
on hyacinth bulbs.

R. bothrina B. & Br. is
the cause of a tea root
disease.

Pseudodematophora
closely allied to the above
forms is described by Beh-
rens 4 on diseased grape

roots. "
He quercina: - Mart 1 eis 9, patios axteiding spore @, te
parasitic on roots and stems and paraphyses. After Hartig, Prillieux and
of young oaks, producinga V##/*

Rhizoctonia-like mycelium, at first white, later brown. Perithecia
are usually abundant. Black sclerotia the size of a pin head are
also present superficially.

R. radiciperda Mas. closely allied to R. necatrix, affects a large
number of hosts, among them apple, pear, peach, cabbage, and
potato.

An undetermined species of this genus is said to cause a cran-
berry disease.!”5 Shear, however, in his extensive studies of cran-
berry diseases, did not find it.

R. aquila (Fr.) d. Not. injures Morus. Its conidial form is

232 THE FUNGI WHICH CAUSE PLANT DISEASE

Sporotrichum fuscum. R. ligniaria (Grev.) Nke. occurs on ash
trees. R. echinata Mas. is reported on “all kinds of Dicotyledon-
ous shrubs and herbs.”

Melonomma Fel. in the species M. henriquesianum Bros. &
Roum. is parasitic on cacao stems.

M. glumarum Miy. is on rice.*

Ceratostomatacez (p. 222)

The fungi of this family are very similar to the Sphzriacez,
but are distinguished by less pronouncedly carbonous perithe-
cia which may be merely membranous, and open by an elongate,
beak-like ostiole. It is a family of only about one hundred
twenty-five species, chiefly saprophytes.

Key To GENERA OF Ceratostomatacee

Spores 1-celled

Spores hyaline............200eeeeeeees -1. Ceratostomella, p. 232.
Spores brown. . .......eececcceeescees 2. Ceratostoma.
Spores 2-celled
Spores hyaline............cceceeeeeves 3. Lentomita.
Spores dark-colored
Perithecia on a cottony stroma....... 4. Rhynchomeliola.

Perithecia not on a cottony stroma... 5. Rhynchostoma.
Spores many-celled
Spores with cross walls only
Spores elongate, 4 to many-celled, hya-

line or brown................... 6. Ceratospheeria.
Spores filiform, many-celled, usually
hyaline
Perithecia erect, astromatic. ....... 7. Ophioceras.
Perithecia horizontal in stromatic
nodules.................ee0ee 8. Cyanogpora, p. 233.
Spores muriform. ..................04. 9. Rhamphoria.

Ceratostomella Saccardo

Perithecia superficial, firm; asci ovate, 8-spored, disappearing
early ; Spores elongate, blunt or pointed, 1-celled, hyaline. About
thirty species. An extensive study of the genus was made by

THE FUNGI WHICH CAUSE PLANT DISEASE 233

Hedgecock ?” who recognizes several species as discoloring lumber.
C. pilifera (Fr.) Wint.* has been described in detail by von
Schrenk as the cause of a blue color in pine wood.”

Cyanospora Heald & Wolf (p. 232)

Perithecia solitary or in clusters of two or three on stromatic
nodules, immersed, horizontal; ostiole lateral, neck short; asci

, Fie. 168.—C. albicedre.
; Upper part of an ascus
Fic. 166.—C. pilifera peri- Fic. 167.—C. albicedre. Sec- showing thickened

thecium, asci and tion of a perithecium in apical wall and coiled
spores. After von itsstroma. After Healdand spores. After Heald
Schrenk. Wolf. and Wolf.

slender, linear, surrounded by a gelatinous matrix, apically thick-
ened; spores filiform, multiseptate, hyaline.
_ A single species.

C. albicedre Heald & Wolf.

Stroma on bark or wood of the host, varying from gray on the
bark to black on wood, lenticular, 1-2 mm. long, solitary or clus-
tered; perithecia 825-1200 x 260-400 u; asci 700~1100 x 8-10 u;
spores 600-1000 x 3 uw; paraphyses numerous, continuous, 1 »
in diameter.

The fungus is described in detail by Heald and Wolf !8 as caus-

234 THE FUNGI WHICH CAUSE PLANT DISEASE

ing whitening of the mountain cedar (Sabina sabinoides) from
Texas to Central Mexico. The seat of infection is the younger
twigs and the young trees, especially where in shade. The disease
may kill the entire trees.

Cucurbitariacee (p. 222)

Perithecia clustered, immersed at first, then erumpent, seated
on a stroma, leathery to carbonous; paraphyses present. The
species numbering about one hundred fifty are mostly saprophytes.

Key To Genera or Cucurbitariaceze

Spores 1-celled

Asci 8-spored
Spores large, green. .........02eeeeee 1. Bizzozeria.
Spores small, hyaline. ..............- 2. Nitschkia.
Asci many-spored. .........-seeeceeeee 3. Fracchiea.

Spores 2 or more-celled
Spores 2-celled
Perithecia bristly, spore walls hyaline.. 4. Gibbera, p. 234.
Perithecia smooth, spore walls brown.. 5. Otthia.
Spores more than 2-celled.............. 6. Gibberidea.
Spores muriform. .............00eee eee 7. Cucurbitaria, p. 234.

Gibbera Fries. !”

Perithecia cespitose on a superficial, thick, Demataceous, conidia-
bearing, carbonous, fragile, bristly stroma; ostiole papillate; asci
cylindric, 8-spored; spores oblong, elliptic, hyaline, uniseriate.

The genus contains some half dozen species, one of which G.
vaccinii (Sow.) Fr. occurs on Vaccinium in Europe. The conidial
form is Helminthosporium vaccinii. Fig. 169.

Cucurbitaria Gray

Perithecia cespitose or more rarely gregarious on a crustaceous
stroma covered by Demataceous hyphe, spherical, glabrous, black,
coriaceous; asci cylindric, 8-spored; spores uniseriate, oblong or
elliptic, muriform, brownish, paraphyses present.

-_THE FUNGI WHICH CAUSE PLANT DISEASE 235

Over seventy specics, several of which are parasitic but none of
importance in America.

C. laburni Pers. is on branches of Cytisus;

C. sorbi Karst on Sorbus twigs;

C. pityophila (Kze.) d Not. on various conifer twigs;

C. berberidis (Pers.) Gray on Berberis;

C. elongata (Fr.) Grev. on Robinia;

C. picez Brothwick, on Picea.

Mycospherellacee (p. 223)

Perithecia mostly subepidermal, rarely subcuticular, finally
more or less erumpent or even superficial, membranous or leathery,

D
Fig. 169.— | ;
Gibbera vac-
cinii, An Fia. 170.—Cucurbitaria berberidis. G,
ascus. After habit sketch; H, ascus. After Lindau
Winter. and Winter.

fragile; asci fasciculate, 8-spored; spores variable, septate, rarely
muriform, hyaline to dark-brown; paraphyses none.

This family of over seven hundred species contains many sap-
rophytes and several very important parasites.

Key To GENERA oF Mycospharellacee

Spores 1 to 2-celled
Spores hyaline or green
Spores 1-celled or not clearly 2-celled
Perithecia very small, on a basal
growth of thick branched hyphe 1. Ascospora, p. 236.

s

236 THE FUNGI WHICH CAUSE PLANT DISEASE

Perithecia without such a basal
growth
Spores typically 1-celled......... 2. Massalongiella.
Spores usually unequally 2-celled. 3. Guignardia, p. 237.
Spores 2-celled
Perithecia produced on living

plants. ......... eee eee eee eee 4, Stigmatea, p. 243.
Perithecia appearing after the death
of the host. ........+00eeeeeee 5. Mycospherella, p. 243.
Spores dark-colored
Spores l-celled. . ........--eseeeeeee 6. Miillerella.
Spores 2-celled
Lichen-inhabiting. ..........-0++6- 7. Tichothecium.
Not lichen-inhabiting. . ........... 8. Pheospherella.
Spores several-celled, hyaline
Spores elongate, with cross walls only
Spores 2 to 4-celled; on lichens. ...... 9. Pharcidia, p. 250.
Spores 4-celled; with a cottony subicu-
WIM is csc seccn ss trees cee Pie sabia ues 10. Sydowia.
Spores many-celled. .. ......--eeeeee 11. Spherulina, p. 250.
Spores muriform..........6.-seseeeeee 12. Pleospherulina, p. 250.

Ascospora Fries (p. 235)

Perithecia borne on a subiculum of thick, brown, much-branched
hyphe, globoid, black, carbonous; asci clavate,
clustered, 8-spored, small; spores 1-celled, hya-
line; paraphyses none.

About half a dozen species, one of which is
Hye Fri heeeeee said by Vuillemin to be the ascigerous form

himantia, Asci. of Coryneum beyerinckii, a wound parasite

. common on drupaceous trees causing gum-
mosis. Cultural evidence of this relationship is lacking, but his
hypothesis may be tentatively assumed.

A. beyerinckii Vuil. Perithecia black, depressed-globose, apapil-
late; ostiole indistinct or absent, 100-130 » in diameter; spores
elliptic-fusoid, ends obtuse, continuous, hyaline, guttulate, 15 x 5-
7 py.

Conidia, 1. (=Phyllosticta beyerinckii) pycnidia globoid with
hyaline spores.

THE FUNGI WHICH CAUSE PLANT DISEASE 237

Conidia, 2. (=Coryneum beyerinckii) conidiophores short,
crowded, from a minute subepidermal stroma; conidia single,
elliptic-oblong, 1 to 5-septate, brown, about 36 x 15 uw. On
drupaceous hosts.

In spots on the bark the mycelium is often sterile, but when
it becomes old distinct pustules usually show in a well developed
subepidermal stromatic tissue and from these pustules, as they
rupture the epidermis, the conidiophores are produced. Conidia
usually abound on the surface of twigs which have borne affected
leaves. They germinate readily and produce either a sooty super-

YB
Miser
teiari(ea

Fig. 172.—Section through a Coryneum pustule on peach.
After Smith.

ficial mold or if on new bark enter the host tissue and induce
spotting.

The conidial stage (Coryneum) of the fungus was grown in arti-
ficial culture by Smith ! but no ascigerous stage corresponding
with that of Vuillemin was found.

A. geographicum (D. C.) Desm. is common on leaves of pome
fruits and A. padi Grev. defoliates cherries in Europe.

Guignardia Viala & Ravaz (p. 236)

Perithecia sunken, globoid or flattened, black, leathery; ostiole
flattened or papillate; asci clavate, 8-spored; spores ellipsoid or
fusiform, hyaline, somewhat arched, 1 or 2-celled; paraphyses
none.

238 THE FUNGI WHICH CAUSE PLANT DISEASE

Over one hundred thirty species are known. Some are impor-
tant parasites.

Conidial forms are found in Phoma and Phyllosticta.

G. bidwellii (E.) V. & R.°® 18719

Perithecia minute, globose, subepidermal, erumpent, perforate;
asci clavate-cylindric, obtuse, 60-70 x 10-13 yu; spores elliptic to
oblong, continuous, 12-17 x 414-5 uy. d

Conidia (=Phoma uvicola, Phyllosticta labrusce, Nemospora
ampelicida) borne in pycnidia 180 x 180 yu, subepidermal, elliptic,

Me Goxosere
fe ree wilh
CSCOSpPare. eee
POS Moermination

Fic. 173.—Diagrammatic section of a perithecium con-
taining ascospores. Germination of a spore at the
right. After Reddick.

thick-walled; conidiophores short, simple; conidia ovate to elliptic,
8-10 x 7-8 uw. Filiform microconidia (“spermatia”’) are borne in
flask-shaped pycnidia 0.1-0.2 x 0.45-0.46 yp.

The fungus has been placed successively in the genera Spheria,
Physalospora, Lestadia and Guignardia.

An extensive synonomy is given by E. Rose”? who concludes
that the name should be G. ampelicida.

It is found on all green parts of Vitis and Ampelopsis, the as-
cigerous stage common only on the mummified fruits.

Perithecia were first found in 1880 by Dr. Bidwell in New J ersey:
They are abundant on berries, which have wintered out doors.

Reddick admirably describes the’ development of the spots as
follows:

THE FUNGI WHICH CAUSE PLANT DISEASE 239

On the leaves the first evidence of the spot is the slight blanching
of a single one of the smaller areola of the leaf. Soon the blanch-
ing extends to adjacent areole, and if an areola is entered it is
usually entirely involved. The small veinlets form the margin
of the spot so that the outline is finely crenulate. By the time
the spot is .3 to .4 mm. in diameter it has a cinereous appearance.
The margin, while sharply defined, is not changed in color. By
the time the spot is 1 mm. in diameter, the margin appears as a
black line, while the remainder of the spot is grayish-brown. A

5 res... 4 Bren
i “ooo ® or Spores

Fic. 174. Diagrammatic section through a pycnidium, show-
ing how the spores are produced and how they germinate.
After Reddick.
little later the margin is a brownish band and the brown gradually
extends inward until the whole spot is covered. As soon as the
brown band attains some width the blackish line on the margin
is to be seen again. A second wave of deeper brown may pass
across the spot: but sometimes it does not get entirely across and
thus leaves a marginal band of a deeper brown than the central
disc. Spots vary in size from 1 mm. up to 8 mm. in diameter, but
in general are 3 to 5 mm. or larger. Occasionally the whole leaf is
destroyed but this is by the coalescence of many spots. When
the spot has attained full size pycnidia protrude from under the
cuticle and either dot the entire surface of the spot with minute
specks or are more often confined to a more or less concentric ring.
The different shades of color are apparent on the under side of

240 THE FUNGI WHICH CAUSE PLANT DISEASE

the leaf on such varieties as have leaves which are smooth beneath.
The pyncidia, however, have never been seen on the under side
of the leaf in our varieties.

On stems, tendrils, peduncles, petioles and leaf veins the
spot in its first appearance is a small darkened depression which
soon becomes very black. On a cane the lesion rarely extends
more than a quarter of the way round, while on a tendril or leaf
petiole it may extend from half to all of the way round. On shoots,
the lesions never extend so
deep as to cut off the sap
supply, but on petioles this
occasionally happens, rarely
so on peduncles, and quite
commonly so-on pedicels and
tendrils. The first indication
of Black Rot on the berry
is the appearance at some
point of a small circular
blanched spot, scarcely 1 mm.

Fic. 175.—Section of a pustule showing in diameter. The blanching

ee ee ee is so slight as to be detected
only by careful observation. It rapidly becomes. more apparent
and has a whitish appearance, the contrast becomes more ap-
parent by the appearance of a brownish line at the mar-
gin. The whitish center increases in size and the brownish or
reddish-brown ring increases in diameter as well as in width
and is quite evident when the spot is 2 mm. in diameter. When
the spot is 3 mm. in diameter the ring is one-half mm. in width
and enough darker to give a bird’s eye effect (a light circular
disc with an encircling darker band). The spot rapidly increases
in size so that in twelve hours more it may be 6 to 8 mm. in diam-
eter, and the encircling band nearly 2 mm. in width. After five
hours more, the spot is 8 or 9 mm. in diameter and there begins
to appear an outer darker band and an inner lighter brown one
which have in some cases a much lighter line between them. The
aureole is thus composed of two or three bands or rings. Eighteen
hours later, the spot is 1 cm. or more in diameter, is distinctly
flattened, and numerous minute brown specks appear on the

THE FUNGI WHICH CAUSE PLANT DISEASE 241

white center of the spot. In five hours more they are so numerous
as to give a blackish appearance.

In New York, Reddick found that the asci begin to ripen in May
and continue to mature throughout the summer being still abundant
in October. The asci swell in water often to twice the length
given above; spores are forcibly ejected from the
asci at maturity, being thrown to a height of
2to 4 cm. There is at one end of the asco-
spore a hyaline vesicle which probably aids in
fixing it to the host. They germinate but
slowly, requiring from thirty-six to forty-eight
hours to show germ tubes. Reddick deter-
mined the incubation period on fruit as from
eight to twenty-one days and found that only
tender leaves still growing are susceptible.
The berry is susceptible even after the calyx
has fallen. The pycnidial spores are said by
some to show a hyaline appendage though
others by careful study fail to find it.”
These spores often live over winter. The Fic. 176.—G._bid-

‘ age ‘ P ar ee wellii; 26, nearly ma-
microconidia which develop in pycnidia similar ture ’‘ascus with
to those of the macroconidia do not occur so Sboresi, 27, mature
abundantly early in the season as they do yee ae
later and seem to be mainly limited to the pressoria. After
fruits. Sporeless pycnidia, pycnosclerotia, also "°d4ic¥-
occur and may eventually develop into perithecia. Conidia on
hyphe of questionable relationship to the fungus are sometimes
seen.

Reddick secured pure cultures in the following ways.

1. In poured plate dilution of asci; some twenty days were
required.

2. By inverting a plate of sterile agar over a bunch of mature
mummies floating on water. The ejected ascospores thus clung
to the agar and gave pure cultures in ten days.

3. By aseptic transfer of the mycelium.

4. By aseptic transfer of pycnospores.

Artificial infections have been reported in Europe from both
conidia and ascospores: Reddick, who made many thousand in-

242 THE FUNGI WHICH CAUSE PLANT DISEASE

oculations under all conceivable conditions, failed utterly of posi-
tive results.

From the Caucasus Prillieux and Delacroix 1** have described a
Guignardia causing a black rot of grapes which is regarded as
distinct from the usual American form, differing both in the peri-
thecial and conidial stages. This is called G. bacce (Cav.) Jacz.
Its conidial form Phoma reniformis eventually covers the whole
berry with pustules. Two kinds of pycnidia
are described.

G. vaccinii Sh. 195

Perithecia on young fruit or flowers, sub-
epidermal, globose, walls thick, carbonous;
asci clavate, 60-80 » long; spores elliptic
or subrhomboidal, hyaline, becoming tinted.

Conidia (=Phyllosticta) borne in pycnidia
Fic. 177.—A vertical sec- similar to the perithecia but thinner-walled,

ee terartin thei 100-120 ; conidia hyaline, obovoid, 10.5-

showing asci. After 13.5 x 5-6 uw. On Vaccinium.

In the decaying berries all sporing forms
of the fungus are rare though in the softened tissues fungous
hyphz abound. Transferred to culture media these hyphe grow
readily and produce spores abundantly.

The conidial form is common in artificial culture; the peri-
thetical form comparatively rare. Pycnidia on leaves are sub-
epidermal, usually hypophyllous, and are quite abundant. The
spores at maturity issue in coils from the ostiole.

The fungus was studied extensively in artificial culture by Shear,
wet sterilized cornmeal proving a most suitable medium. Pycni-
dia appeared in four to eight days after inoculation and spores were
mature at twelve to eighteen days. Both pycnidia and perithecia
were obtained in pure cultures. The rarity of cultures able to pro-
duce perithecia is explained by Shear on the assumption “that
there is some inherent potentiality in the mycelium of the fungus
in certain strains, races, or generations which causes it to produce
the ascogenous stage whenever conditions for its growth are favora-
ble, i. e., on favorable culture media without special reference to
their exact composition or environment or on the leaves of its nat-
ural host.’”’ Conclusive infection experiments have not been made.

THE FUNGI WHICH CAUSE PLANT DISEASE 243

G. thee Bern. !° grows on tea leaves.
G. (Lestadia) buxi Desm. The perithecia develop on box

leaves. It is probably saprophytic although sometimes considered
@ parasite.

Stigmatea Fries (p. 236)

Perithecia subepidermal, or subcuticular, thin, black; asci
oblong, subsessile, 8-spored; spores ovoid-ellipsoid, 2-celled, yel-
lowish or hyaline; paraphyses present. The
ascigerous stage of two species of Entomo-
sporium are said by Lindau” to belong to
this genus. Atkinson, however, places them in
the genus Fabrea, see p. 149.

S. juniperi (Desm.) Wint., on living leaves
of Juniperus in Europe and America and on Fio. 178—Stiematen
Sequoia in California. Asci and spores.

Perithecia scattered, lenticular or subhemi- se tee
spheric, rough, 200-300 u in diameter, asci rounded and obtuse
above, abruptly tapering below into a short stipe, 60-70 x 20 u;
spores ovate-lanceolate, unequally 2-celled, yellowish-hyaline, 16-
25 x 6-8 uy.

S. alni occurs on alder leaves in Europe.

Mycospherella Johans. (p. 236)

Perithecia subepidermal, suberumpent, globose-lenticular, thin,
membranous, ostiole depressed or short papillate; asci cylindric
to clavate, 8-spored; spores hyaline or greenish, ellipsoid, 2-celled;
paraphyses none.

This large genus of over five hundred species formerly known as
Spherella contains several serious plant pathogens. It is often
found in its conidial forms as: Ramularia, Ascochyta, Septoria,
Phleospora, Cercospora, Ovularia, Cylindrosporium, Phyllosticta,
Graphiothecium, Phoma, Diplodia or Septogleeum. In many cases
the relationship of the ascigerous and conidial forms is as yet but
imperfectly known. The perithecia are usually found late in the
season, often only on leaves that have borne the conidial stage in
the summer and have then wintered.

244 THE FUNGI WHICH CAUSE PLANT DISEASE

M. fragarie (Tul.) Lin.”
Perithecia on leaves, are produced late in the season, globose,
subepidermal, membranous, black, thin-walled; asci few, clavate,

Fic. 179.—Mycospherella fragariz. “‘Socauniocnons burst-
ing through the epidermis; c, arising from apex of a
pycnidium; d, summer spores, one germinating; e, section
of a spermogonium; f, section of perithecium; g, ascus
containing eight two-celled spores. After Longyear.
8-spored, 40 u long; spores hyaline, 2-celled, with acute tips,
15 x 3-4 p.

Conidia (=Ramularia tulasnei) abundant in early summer on
reddish spots, stromatic, conidiophores simple; conidia elliptic
20-40 x 3-5 yu, 2 to 3-celled. On Fragaria.

The life history was first studied in 1863 by the Tulasne brothers
under the name Stigmatea. The generic name was changed to
Spherella in 1882 and later to Mycospherella.

THE FUNGI WHICH CAUSE PLANT DISEASE 245

The slender mycelium pervades the diseased areas disorganizing
the host cells and resulting in reddish coloring of the sap. Ob-
servations of Dudley ™ indicate that the mycelium or portions of
it can remain alive over winter in the host tissue ready to produce
abundant conidia in the spring.

The most abundant conidial stage is the Ramularia-form
(Fig. 179) which abounds all summer. Sowings of these conidia,
under conditions of humid atmosphere, result in characteristic
spots in from ten to eighteen days. Toward winter sclerotial
bodies are formed from the mycelium. These in culture dishes
have been seen to produce the typical summer conidia. Some of
these sclerotia-like bodies have been reported as ‘‘spermogonia,”
bearing numerous “spermatia’’ 1x3 yu. Perithecia abound in au-
tumn. ‘These are larger than the spermogonia and are usually
embedded in the leaf tissue, though they sometimes appear super-
ficially. Conidiophores are often borne directly on the perithecium
wall. Ascospores germinate within the ascus. From the mycelium
resulting from ascospores Dudley ™ observed the formation of
typical summer conidia.

M. grossulariz (Fr.)

Perithecia hypophyllous, gregarious, spherical, with minute
ostiole, black; asci short-pedunculate, clavate, 55-66 x 8-12 uy;
spores fusoid, filiform, curved or straight, uniseptate, hyaline,
26-35 x 3-4 p.

It has been reported on the gooseberry associated with Cer-
cospora angulata and Septoria ribis.

M. rubina (Pk.) Jacz.

Perithecia minute, gregarious, submembranous, obscurely papil-
late, subglobose or depressed, erumpent, black; asci cylindric,
subsessile, 70-80 x 10-12 y; spores oblong, obtuse, uniseptate,
generally constricted in the middle, 15 x 6-7 yu, upper cell broadest.

Conidia (=Phoma) are associated with the perithecia and are
supposed to be genetically connected with them as is also a second
spore form (=Coniothyrium).

The species is held responsible for bluish-black spots on rasp-
berry canes.

M. cerasella Aderh.™! is reported as the perithecial stage of
Cercospora cerasella common on cherry.

246 THE FUNGI WHICH CAUSE PLANT DISEASE

M. sentina (Fr.) Schr.

Perithecia, 80-110 »; on dead spots of leaves, the long ostiole
erumpent; asci clavate, 60-75 x 11-13 u, colorless; spores fusiform,
curved or straight, 26-33 x
4p.

Conidia (=Septoria piricola)
borne in pycnidia which are
similar in size and form to the
perithecia; conidia filiform,
curved, 3-celled, 40-60 x 3 u.
On pear and apple.

The conidial form was men-

ara A tioned in America as early as
Fic. 180.—M. sentina, Septoria stage. 1897 by Atkinson ** and was

Portion of a section through a pearleaf the subject of a comprehensive

cade cella ope spongy pareneayina; a, Dulletin by Duggar in 1898.

ae Pamper out Theascigerous stage was demon-

strated by Klebahn in 1908.?°?

The pycnidia, mainly hypophyllous, are sunk deeply into the
leaf tissue and are surrounded by a delicate pseudoparenchyma.
The conidia are distinctly tinted, green or smoky.

The perithecia are numerous, and crowded on grayish spots,
hypophyllous, on old wintered leaves. They are without stroma.
Klebahn by inoculations (June, 1904) with ascospores secured
spots in fifteen days and pycnidia in twenty-
nine days, bearing the characteristic conidia.
From ascospores he also made pure cultures
which soon developed pycnidia with conidia.
Pure cultures made from conidia in the hands
of both Klebahn and Duggar have failed to
give typical perithecia.

M. citrullina (C. O. Sm.) Gros. Fic. ree

Perithecia roughish, dark-brown or black, ee meant ae
depressed-globose to inverted top-shaped, Seat eos sg
usually with a papillate ostiole, densely
scattered, erumpent, 100-165 y; asci cylindric to clavate, 45-58 x
7-10 uw; spores hyaline, oblong-fusoid, constricted at the sep-
tum.

THE FUNGI WHICH CAUSE PLANT DISEASE 247

Conidia (=Diplodina citrullina) Pyenidia similar to the peri-
thecia, spores 2-celled, hyaline, straight or curved, more or less
cylindric, 10-18 x 3-5 py.

The fungus was isolated in pure culture by Grossenbacher 2°
from muskmelons by direct transfer of diseased tissue to potato
agar. Inoculations from these cultures proved the fungus capable
of entering healthy uninjured tissue, the ’
disease showing about six days after in- FR
oculation. The brownish pycnidia origi-
nate from an extensive subepidermal,
partially cortical, much-branched, brown-
ish mycelium but soon break through and :

: » Fic. 182.—M. sentina. A,
appear almost superficial. When mois- “‘perithecium and asc, Af.
tened, spores issue in coils. Darker peri- t¢* Klebabn.
thecia, nearly superficial, are found on old diseased spots. Both
ascospores and conidia are capable of causing infection. Inocu-
lations on pumpkin and watermelon gave positive results; these
on cucumber, West Indian gherkin, squash, pumpkin, and gourd
were negative. The same fungus has been reported as cause of
canker of tomatoes.”

M. tabifica (P. & D.) Johns.2"?"

Perithecia rounded, brown; asci oblong-clavate, 8-spored; spores
hyaline, upper cell larger, 21 x 7.5 y.

Pycnidia (=Phoma) subglobose; conidia elliptic, hyaline, 5-7 x
3.5 mw, escaping as a gelatinous cirrus.

This conidial form, common on beets causing leaf spot through-
out the summer, is said by Prillieux and Delacroix to be connected
with M. tabifica the perithecial form, which is found upon the
dead petioles at the end of the season. Convincing evidence™ of
this connection seems wanting. The conidial stage*” is variously
known as Phoma bete#, Phoma spherosperma, Phyllosticta
tabifica. The Phoma-form from stems and rotten roots and the
Phyllosticta-forms from leaves were both studied by Hedgcock 7”
in pure cultures on many media and many inoculations were made,
all leading to the conclusion that the Phoma and the Phyllosticta
are identical.

M. tulasnei Jacz.2"!

Perithecia subglobose, minute; asci cylindric. fusoid; spores

248 THE FUNGI WHICH CAUSE PLANT DISEASE

oblong, rather pointed, upper cell in the ascus somewhat larger
than the others, 28 x 6.5 yu.

Conidia of two kinds, (1) (=Cladosporium herbarum) tufts
dense, forming a velvety blackish-olive, effused patch, conidio-
phores erect, septate, rarely branched, often nodose or keeled;
conidia often in chains of 2 or 3, subcylindric pale-olive, 1 to
3-septate, 10-15 x 4-7 ». (2) (=Hormodendrum cladosporioidies
Sacc.) Hyphe erect, simple, bearing apically or laterally a tuft

\s

Fic. 183.—M. citrullina, A. pyenidium (Diplodia) in sec-
tion, B, perithecium; C, ascus and spores. After Grossen-
acher.

of small, elliptic, continuous, brown conidia in simple or branched
chains.

It is the cause of serious disease in Europe, being especially
injurious to cereals after a rainy season preceded by a drought
and is found also parasitic on pea, apple, raspberry, cycad, agave
and as a saprophyte almost anywhere.

M. stratiformans Cobb. affects sugar cane. The perithecial
stage alone is known.?” Further study is desirable.

M. gossypina (Cke.) Er.?!"?!7

Perithecia ovate, blackish, partly immersed, 60-70 x 65-91 pn;
asci subcylindric, 8-10 x 40-45 yu; spores elliptic to fusoid, con-
stricted at the septum, 3-4 x 15-18 u.

Conidia (=Cercospora gossypina); hyphe flexuose, brown,

THE FUNGI WHICH CAUSE PLANT DISEASE 249

120-150 w» high; conidia attenuate above, 5 to 7-septate, hyaline,
70-100 x 3 uw. On cotton.

The intercellular mycelium is irregular, branched, septate, and
produces tuberculate stromata from which the brownish hyphe
arise. The perithecia, much less common, are partly immersed
in old leaves.

M. morifolia (Fcl.) Lin. in its conidial stages, Cylindrosporium
mori and Septoglceum mori, affects Morus.

M. maculiformis (Pers.) Schr. grows on many trees. Especially
common are its conidial stages Cylindrosporium castinicolum and
Phyllosticta maculiformis.

M. rosigena E. & FE. ?!*?9

Amphigenous on reddish-brown, purple-bordered spots which
are about 3-4 mm. in diameter; perithecia thickly scattered over
the spots, minute, 60-75 yu, partly erumpent, black; asci sub-
clavate to oblong, 25-30 x 8-10 u; spores biseriate, clavate-
oblong, hyaline, 1-septate, 10-12 x 2 u, ends subacute.

It causes leaf spots of rose in America.

. brassiceecola (= Phyllosticta brassicecola) grows on cabbage.
. punctiformis Pers. produces leaf spot on oak, lime, hazel;

. fagi Auser. on beech;

. pinifolia Duc. on pine leaves; *”

. abietis (Rost.) Lin. a leaf disease of balsam.”

taxi Cke. grows on yew;

. hedericola Desm. on Hedera leaves;

. gibelliana Pass. on Citrus leaves;

. Vitis Fel. on grape leaves;

. elastice Kr. ??! on Ficus elastica.

cydonie Vogl.?2 on quince is probably identical with
M. sentina on pear and apple.

M. ulmi Kleb. occurs on elm with its conidial forms, a Phleo-
spora and Phyllosticta bellunensis.

M. comedens Pass. is on the same host.

M. larcina Hart. and its conidial form Leptostroma larcinum
affect larch, causing defoliation.

M. leefgreni N. on oranges and M. coffee N. on coffee are
tropical forms.

M. populi Schr. (=Septoria populi) is on Populus.*

SSEEEESSESEA

250 THE FUNGI WHICH CAUSE PLANT DISEASE

M. pinodes Berk & Blox.

Perithecia numerous, 100-140 yu; asci oblong-cylindric, 58-62 x
12 w; spores 2-rowed, 14-16 x 5.

Pycnidia (=Septoria pisi), with large ostiole; spores 35-45 x 3-
3.5 u, 1 to 3-septate. On pea stem and leaves. 1°
. primule is on primrose;

. tamarindi on tamarinds in Africa.

. cinxia Sace. is on lilies, causing leaf blight;

. fusca Pass. on the gladiolus;

. coffeicola on coffee in Mexico.

. shiraina Miy. and M. hondai Miy. are on rice.
. convexula (Sch.) Rand.

Perithecia hypophyllous, gregarious or scattered, finally erum-
pent, 100-200 yu in diameter, papillate at maturity; no paraphyses;
asci fasciculate, 54-100 x 9-11 yu, &spored; spores allantoid,
l1-septate, hyaline, 18-27 x 3.5-5.5 u.

Forming a leaf spot on pecans.3

An undetermined species of Mycospherella has been reported
on the grape by Rathay.?”

Many other species are known on ferns, cereals, lilies, and va-
rious trees and herbs.

In the genus Pharcidia. P. orze Miy. is on rice.*®

In Spherulina the species Spherulina taxi Mass. is injurious on
yew leaves.

eee eee.

Pleospherulina Passer (p. 236)

Perithecia subepidermal, erumpent, small, globoid or lenticular,
black; asci 8-spored, clavate; spores muriform, hyaline; paraphyses
none.

P. briosiana Pol. causes a leaf disease of alfalfa in Italy.

Pleosporacee (p. 223)

Perithecia sunken, at length erumpent, or from the first more
or less free, membranous or coriaceous, usually papillate; asci
clavate-cylindric, double-walled; spores variable, but usually
colored, oblong, fusoid or elliptic; paraphyses present.

An order of some nineteen hundred species most of which are

saprophytes, although several are parasites, some of considerable
importance.

THE FUNGI WHICH CAUSE PLANT DISEASE 251

Key To Grenrra or Pleosporacee

Spores 1-celled
Spores with blackish appendages, elon-
gate, hyaline. ....................
Spores unappendaged
Spores elongate, hyaline or light yel-
TOW sis Ric diend Gelade bees gestures
Spores elongate, fusoid, hyaline; tips

Spores 2-celled
Spores with the 2 cells very unequal in
size

Upper cell the smaller; parasitic on
RCC. os soos eas nee eign odes
Basal cell the smaller; saprophytes. .. .

Spores with both cells about equal
Perithecia hairy; spores hyaline or

Perithecia smooth
Spores hyaline....................
Spores brown
Perithecia not stromatic.........
Perithecia borne on a stroma. ....
Spores more than 2-celled
Spores elongate, with cross walls only
Spores appendaged
Spores clavate, 4 to 6-celled, brown,
the basal cell hyaline long-
appendaged............-..---
Spores filiform, many-celled, with
filiform appendages...........
Spores not appendaged
Spores fusoid or elongate, blunt, never
filiform or separating into cells
Spores elongate, 3 to many-celled,
hyaline or brown
Spores with a thick, dark-brown
epispore and a thin hya-
line endospore, 4-celled, el-
lipsoid...............005-

1. Urospora.

2. Physalospora, p. 252.

3. Therrya.

4. Arcangelia.

5. Apiospora.

6. Venturia, p. 253.
7. Didymella, p. 255.

8. Didymospheria, p. 256.
9. Gibbellina, p. 256.

10. Rabentischia.

11. Dilophia, p. 257.

12. Chitonospora.

252

Spores not as above, elongate
3 to many-celled hyaline or

THE FUNGI WHICH CAUSE PLANT DISEASE

brown
Perithecia hairy. ........... 13. Pocospheria.
Perithecia smooth
Spores hyaline............ 14. Metaspheria, p. 257.
Spores yellow or dark-
brown............-.. 15. Leptospheria, p. 257.
Spores fusoid, 7 to many-celled,
the central cell enlarged and
brown, the rest hyaline...... 16. Heptameria.
Spores fusoid, up to 30-celled hya-
line or brown.............. 17. Saccardoella.
Spores filiform, often separating into
cells
Perithecia hairy. ............... 18. Ophiocheta.
Perithecia smooth. . ............ 19. Ophiobolus, p. 259.
Spores muriform
Asci 8-spored
Spores appendaged................ 20. Delacourea.
Spores not appendaged
Perithecia hairy. ......... etauntes 21. Pyrenophora, p. 262.
Perithecia smooth. . ............ 22. Pleospora, p. 259.
Asci 16-spored.............-..00000- 23. Capronia.

Physalospora Niessl. (p. 251)

Perithecia subglobose, covered, membranous, or coriaceous,

Fic. 184.—Physalospora. Perithecia and
ascus. After Winter.

black, with the ostiole erum-
pent; asci clavate-cylindric;
spores ovoid or oblong, con-
tinuous, hyaline or subhya-
line; paraphyses present.

This genus contains over
one hundred thirty species, a
few of which are parasitic on
twigs and leaves. Some spe-
cies possess a Glceosporium
as the conidial form.

P. gregaria and its conidial stages Tetradia salicicola and

THE FUNGI WHICH CAUSE PLANT DISEASE 253

Macrodendrophoma salicicola cause black cankers on oziers in
Ireland.??4

P. abietina P. & D.”* is found on Picea; P. cattleyze Maub. &
Las. in its conidial form, Gleeosporium macropus”* parasitizes
Cattleya. P. laburni Bon. is on Cytisus.

P. woronini M. & F. is described as causing a disease of grapes
in the Caucasus.?2”

P. vanille Zimm. is on vanilla;

P. fallaciosa Sacc. on banana leaves.

Venturia Cesati & de Notaris (p. 251)

Perithecia superficial or erumpent, bristly, ostiolate, membra-
nous, dark colored; asci sessile or short stipitate, ovate or saccate;
spores oblong to ovoid elliptic, hyaline or ‘yellowish; paraphyses
usually none.

The conidial stages in some cases belong to the form genus
Fusicladium and constitute the parasitic portion of the life history
of the fungus, the ascigerous form usually being limited to old or
wintered parts of the host.

There are over fifty species, several of which cause diseases.

Vv. pirina Aderh.?2" 312, 313, 350

Perithecia gregarious, smooth or bristly, globoid, 120-160 uy;
asci cylindric; spores unequally 2-celled, yellowish-green, 14-20 x
5-8 yb.

Conidia (=Fusicladium pirinum) effused, velvety, blackish-olive,
conidiophores short, wavy or knotted, thick-walled; conidia ovate
fusoid, olive, becoming 1-septate with age, 28-30 x 7-9 un.

It is found on the pear wintering in perithecial form on leaves,
and in conidial form, or as mycelium on twigs.

V. inzequalis (Cke.) Aderh. (=V. pomi [Fries] Winter).

Perithecia globose, short-necked, 20-160 4, smooth or bristly
above; asci cylindric, 40-70 u long; spores yellowish-green, un-
equally 2-celled, upper cell shorter and broader, 11-15 x 4-8 yp.

Conidia (=Fusicladium dendriticum) effused, velvety, forming
dendritic patches of compact masses of erect closely septate
brown mycelium; conidiophores closely septate, brown, 50-60 x
4-6 uw, wavy or nodulose; conidia solitary, terminal, obclavate,

254 THE FUNGI WHICH CAUSE PLANT DISEASE

y

=D

De

«

StI

Fig. 185.—V. inequalis. A, portion of a section through a scab spot on apple; 6, spread-
ing under and lifting the cuticle, a; c, partly disorganized cells of the apple; e, healthy
cells of the apple. B, two conidiophores with summer spores f. C, spores ger-
minating. D, portion of a section showing a perithecium and asci. E, two asci, each
containing 8 two-celled spores, three of which are shown at F. After Longyear.

THE FUNGI WHICH CAUSE PLANT DISEASE 255

yellowish-olive, continuous when young but at length septate,
30 x 7-9 yu.

Its hosts are apple and other pomaceous fruits except the pear.
Conidia of special form have been known under the name Napi-
cladium soraueri.

The two last conidial forms have been long regarded as identical
and are found in literature as Fusicladium dendriticum. The
olive-green mycelium in both cases grows subepidermally in the
leaf and fruit killing the epidermis and forming subepidermal
stromata from which conidiophores are produced. Stromatal
development is also said to be often subcuticular, resulting in a
separation of the cuticle from the epidermis.

The conidia are produced apically on short stalks and as each
conidium is cut off the conidiophore grows forward, leaving scars
equal in number to the conidia produced. Pyenidia have been
reported on the mycelium in twigs in winter.**?

Perithecia first form on the lower leaf surface in October and
mature in April. They are most abundant when protected by
sod or piles of leaves, and appear as small black pustules often
on grayish spots. Their connection with the conidial stage was
first shown by Aderhold 2%! and confirmed by Clinton.”

Thefungusfrom apple was cultured on apple-leaf-agar by Clinton.
Pure colonies developed in 4 to 5 days and infection was secured
on leaves. Cultures from ascospores gave rise to typical conidia.

V. crategi Aderh. occurs on Crateegus. ;

V. cerasi Aderh. (=Fusicladium cerasi) is found on cherries.
Aderholt 233 demonstrated the connection between the ascigerous
and conidial forms.

V. ditricha (Fr.) Karst. (=Fusicladium betula) is found on
birches; V. tremule Aderh. (=Fusicladium tremule) on aspen;
V. fraxini Aderh. (=Fusicladium fraxini) on ash;

V. inzequalis var. cinerascens Lin. (=Fusicladium orbiculatum)
on Sorbus.

Didymella Saccardo (p. 251)

Perithecia covered, membranous, globose-depressed, minutely
papillate; black; asci cylindric or clavate’ spores ellipsoid or
ovate, 2-celled, hyaline; paraphyses none.

256 THE FUNGI WHICH CAUSE PLANT DISEASE

Of the some one hundred twenty species D. citri N. is of in-
terest since it forms cankers on orange trees in Brazil.

Didymospheria Fuckel (p. 251)

Perithecia immersed, later erumpent; asci cylindric to clavate,
8-spored; spores elliptical to ovate, 2-celled, brown.

This genus differs from Didymella chiefly in the dark-colored
spores. It contains some one hundred twenty species and has
occasional parasitic representatives on leaves and twigs.

c J
XK
AT Fic. 187.—Didymo- _— Fra. 188. — Dilo-
Fic. 186.—Didymella. A, spheria. C, an as- phia graminis.
ascus; B, hymenium of cus; D, conidio- J, ascus; K,
a pycnidium. After phore and conidia. spore. After
Brefeld. After Brefeld. Winter.

D. sphezroides (Pers.) Fr. is on Populus leaves in Europe.

D. catalpz.3“4

Perithecia very small, scattered, embedded in the tissue of the
leaf, pyriform to nearly spherical, varying in width from 48-104 yu
and in depth from 64-140 y; ostiole broadly conical, erumpent;
asci 8-spored, cylindrical, usually somewhat curved; paraphyses
few or wanting; spores oblong-elliptical, hyaline or yellowish,
uniseptate, constricted in the middle, 9.6-13 x 3-4 ». On Catalpa.

D. populina Vuill., causes death of peplars in Europe.?34

D. epidermidis Fr. is found on Berberis, Sambucus and Salix.

Gibbellina Passerina (p. 251)

Stromata black, sunken in the substratum, formed of thin, closely
interwoven hyphe; perithecia sunken in the stromata, globose;

THE FUNGI WHICH CAUSE PLANT DISEASE 257

asci elongate-globoid; spores elongate, 2-celled, brown; paraphyses
present. Genus of one species.

G. cerealis Pers. causes a serious grain disease in Europe, es-
pecially of wheat in Italy.?%

Dilophia Saccardo (p. 251)

Perithecia sunken, not erumpent, delicate, dark-colored, ostiole
papillate; asci long-cylindric; spores elongate-fusiform to filiform,
multicellular, each end appendaged, the appendages hyaline, the
spores hyaline or yellow. Fig. 188.

There are three species, one of which D. graminis (Fcl.) Sacc.
parasitizes rye and wheat in Europe. The conidial form Dilo-
phospora graminis Desm. is especially common.

Metaspheria Saccardo (p. 252)

Perithecia clavate, sunken in a stroma, at first covered; leathery,
dark, with ostiole; asci cylindric to clavate, 8-spored; spores ellipsoid,
elongate, blunt or appendaged, 3 to many-celled; paraphyses filiform.

M. albescens Thiam. is on rice in Japan.

Leptospheria Cesati & de Notaris (p. 252)

Perithecia at first subepidermal, at last more or less erumpent,
subglobose, coriaceo-membranous, globose, ostiole usually papil-
late; asci subcylindric; spores ovoid, oblong or fusoid, two or more
septate, olivaceous, yellowish or brown.

There are about five hundred species, many of which in the
conidial forms embrace Cercospora, Phoma, Hendersonia, Sporides-
mium, Septoria, Coniothyrium or Cladosporium.

L. coniothyrium (Fcl.) Sacc.*! 3!

Perithecia gregarious, subepidermal, depressed, globose, black;
ostiole papillate, erumpent; asci cylindric, stipitate, 8-spored,
66-96 x 4-6 yu; spores l-rowed, oblong, 3-septate, constricted,
fuscous, 10-15 x 3.5-4 nz.

Pycnidia (=Coniothyrium fuckelii), similar to perithecia; spores
ovate, continuous, fuscous.

It occurs on black and red raspberries and numerous other hosts.

Stewart °14 verified the assumed identity of the conidial form
with this ascigerous fungus by pure culture studies.

258 THE FUNGI WHICH CAUSE PLANT DISEASE

L tritici (Gar.) Pass *!° (=Pleospora tritici). On wheat.?*

Perithecia innate, globose, black, papillate; asci clavate, short-
stipitate, 8-spored; paraphyses filiform, 48-50 x 15-16 u; spores
2-seriate, round, fusoid, 3-septate, constricted, pale, 18-19 x 4.2-
5.5.

L. herpotrichoides d. Not.” parasitizes rye causing the stalks
to break at the nodes;

Sn

Fic. 189.—Cross-section of raspberry bark showing
two perithecia of L. coniothyrium at the top, A, and
two pycnidia of Coniothyrium fuckelii, at the bot-
tom, B. 4. An ascus of L. coniothyrium. 5. Spores
of L. coniothyrium. After Stewart.

L. sacchari V. B. d H. occurs on sugar-cane.®

L. napi (Fel.) Sacc. (=Sporidesmium exitiosum) is found on
rape; L. phlogis Bos. (=Septoria phlogis) on Phlox;

L. circinans (Fcl.) Sacc. kills alfalfa roots, potato, clover, beets
and other hosts; 7%

L. vitigena Schul. occurs on grape tendrils;

L. stictoides Sacc. on Liriodendron; L. rhododendri on Rho-
dodendron;

L. iwamotoi Miy. on rice;

THE FUNGI WHICH CAUSE PLANT DISEASE

L. taxicola R. K. on Taxus canadensis :

L. vagabunda Sacc. spots linden
is perhaps Phoma tiliz.?9

branches. Its conidial form

Ophiobolus Riess (p. 252)

Perithecia scattered, subglobese,

fusiform, hyaline or yellowish.

submembranous, covered or
suberumpent, ostiole papillate or elongate; asci cylindric; spores

4

ie

Fic. 190. — Ophio- Fic. 191.—Pleospora from

bolus. B, ascus;
C, spore. After
Lindau and Win-
ter.

passion-fruit. The spores
are just beginning to ger-
minate, the end cells start-
ing first. After Cobb.

A genus of some one hundred twenty-five species.

O. graminis Sacc. and O. herpotrichus Sacc. occur on grasses

and are quite injurious in Europe.*””
O. oryzee Miy. is found on rice.*®

Pleospora Rabenhorst (p. 252)

Perithecia covered at first, later more or less erumpent, usually
membranous, black, globose; asci oblong to clavate; spores elon-

gate or ovate, muriform; paraphyses present.

260 THE FUNGI WHICH CAUSE PLANT DISEASE

Conidia occur as Macrosporium, Alternaria, Cladosporium,
Sporidesmium, Phoma, Helminthosporium.

There are over two hundred twenty-five species, mostly sap-
rophytic. Many conidial forms whose connection to this genus
have not yet been definitely proved probably belong to it and are
in many instances parasites.

P. tropeoli Hals. is reported as the cause of disease of the cul-
tivated Nasturtium.”

Perithecia pyriform, 140-160 u; asci oval, one-sided, spores
hyaline or very light-olivaceous, 25-35 x 6-8 y.

The Alternaria-form was grown from the ascospores by Halsted
and from the Alternaria spores, grown in pure culture, perithecia
were obtained in about twelve days.

P. albicans Fel. occurs on chicory as Phoma albicans;

P. hyacinthi Sor. on hyacinths with its conidia as Cladosporium
fasciculare; P. hesperidearum Cotton, in its conidial form, Spori-
desmium pyriforme, causes a black mold on oranges.

P. herbarum (Pers.) Rab. (conidia=Macrosporium commune)
is a common saprophyte which sometimes becomes parasitic.

P. pisi (Sow.) Fcl.?!° is found on the garden pea;

Perithecia and spores as in P. herbarum but spores more narrow.

P. ulmi. Fr. causes an elm leaf spot. P. infectoria Fcl. a com-
mon saprophyte, parasitizes tobacco.

P. oryzz Miy. is on rice;

P, negundinis Oud. is injurious to nursery stock of Negundo;

P. putrefaciens (Fcl.) Fr. (conidia=Sporidesmium) is on carrots.

Pleospore on grains.”4) 51

Several species of Pleospora with their attendant conidial forms
of Helminthosporium and Alternaria are known on various grains
and grasses. Cross inoculation experiments have shown here
biologic specialization similar to that encountered among the
Erysiphez, in that conidia or ascospores from one host usually
give negative results on host species other than that on which they
grew. Thus Diedicke *4? says the Pleospora of Bromus cannot
be grown on Triticum repens nor on cultivated barley or oats.
Helminthosporium was formerly thought to be the conidial stage
of all of these grain Pleosporas, but recent work of Diedicke shows
that one form which he regards as P. trichostoma (Fr.) Wint.

THE FUNGI WHICH CAUSE PLANT DISEASE 261

possesses an Alternaria conidial form. Following Diedicke, the
forms given below would be recognized.

P. bromi Died.

Perithecia brown, hairy; asci 189-288 x 34-59 y, saccate, thin-
walled; spores 2-seriate, golden-brown, 4-celled, 48-83 x 19-33 u.

Conidia (=Helminthosporium bromi) on brownish spots, 108-
150 x 13-20 u, 5 to 7-celled, dark colored. On Bromus.

P. gramineum Died.

Conidia (=Helminthosporium gramineum); conidiophores short,
subflexuose, light-brown; conidia solitary, elongate-cylindric, 4 to
7-celled, 15-19 yw wide and of variable length.

The mycelium invades the tissue causing long brown spots.
These later become covered with an abundance of conidiophores
which emerge through the stomata. Potter also reports in-
vasion and complete occupation of ovaries by the mycelium.™
Sclerotia-like bodies are
formed on leaves and
stems. They were first
seen in artificial cul-
tures of the fungus by
Ravn 748 and have been
since found in nature
(Noack 744),

The conidiospores
have been shown to be
long-lived, and spring
infection begins largely Fic. 192.—P. trichostoma. 1, group of asci, 2, a
from conidia carried single spore at the apex of an ascus. After

s Diedicke.
over winter on seed.
Extensive study was made of the conidial form by Ravn who
found the mycelium to be of two kinds, one aérial and hyaline,
the other strict and dark. It grew well on acid or neutral media.

Careful infection experiments (Ravn) proved the pathogenicity
of H. graminum for barley but showed it incapable of infecting
oats, rye or wheat.

Ravn regards the disease produced by H. gramineum as often
general, not local, in that the mycelium may invade the growing
points, resulting in infection of all the leaves.

262 THE FUNGI WHICH CAUSE PLANT DISEASE

P, tritici-repentis Died. is found on Triticum repens (=Agropy-
ron repens.) Conidia=Helminthosporium tritici repentis.

P. trichostoma (Fr.) Wint. (=Pyrenophora trichostoma (Fr.)
Sacc.?4?

Perithecia gregarious, innate, conical, black, ostiole surrounded
by black hairs, which are simple, septate, 6-8 » in circumference;
asci clavate 300 x 40 yu; spores broadly oblong, obtuse, unequally
4 to 6-septate, muriform, brownish, 52 x 20 u; paraphyses branched.

On rye with the conidial form =Alternaria trichostoma Died.

In the present state of our knowledge little is to be gained by
recognition of these purely “biologic species,” and all the forms
may be grouped under the name P. trichostoma, recognizing the
fact that it shows biologic differentiation.

Two hypothetical forms P. teres Died. and P. avene Died.
pertain to Helminthosporiums of corresponding names.

Massariacez (p. 223)

Stroma none; perithecia separate, sunken, not erumpent, open-
ing by a small pore, leathery or carbonous, compact; spores usually
surrounded by a jelly-like substance; paraphyses present.

This family of ten genera and about one hundred twenty-five
species contains only one parasite of interest.

Key To GENERA or Massariacee

Spores 1-celled
Spores not surrounded by a jelly-like sub-

BtANCES sera even ede eause a eee 1. Enchnoa.
Spores surrounded by a jelly-like sub-
STANCE) 2 ceed gitar dans wads wee we 2. Pseudomassaria.

Spores several-celled
Spores not muriform
Spores hyaline or yellow
Spores ellipsoid to spindle-shaped,

several-celled, hyaline. ........ 3. Massarina.
Spores spindle-formed, curved, 3 to 4-
celled, yellow................. 4. Ophiomassaria.

Spores 2 to 4celled, elongate, hya-
Uin@ shee shes cede oben 5. Charrinia, p. 263.

THE FUNGI WHICH CAUSE PLANT DISEASE 263

Spores brown
Spores 2-celled
Perithecia scattered irregularly... 6. Phorcys.
Perithecia in circular clusters..... 7. Massariovalsa.
Spores more than 2-celled
Spores ellipsoid to spindle-shaped,

many-celled. ............... 8. Massaria, p. 263.
Spores cylindric, bent, 8-celled. . 9. Cladospheria.
Spores muriform...................0-- 10. Pleomassaria.

Massaria theicola Petch invades the ducts of the tea plant. The
genus Charrinia is said by Viala & Ravaz * to contain the ascige-
rous form of Coniothyrium diplodiella (Speg.) Sacc.

Gnomoniacee (p. 223)

Perithecia sunken, with an elongate, cylindric, beak-like ostiole,
rarely with a papillate one; leathery or membranous, rarely borne
on a stroma; asci mostly thickened apically and opening by a pore;
spores hyaline; paraphyses usually absent.

A family of about one hundred fifty species; four genera con-
tain important pathogens.

Key to GENERA oF Gnomoniacer

Spores 1-celled
Mouth of the perithecium short

Asci cylindric, 8-spored.............. 1. Phomatospora.
Asci clavate, 2-spored. .............. 2. Geminispora.
Mouth of the perithecium elongate, beak-
like
Mouth of the perithecium straight
Asci many-spored. ...........-0065 3. Ditopella, p. 264.
Asci 8-spored
Spores ellipsoid or fusoid
A clypeus present............. 4, Mamiania.
Stroma present. .............- 5. Glomerella, p. 264.
Stroma absent...............- 6. Gnomoniella, p. 273.

Spores elongate fusoid, or filiform 7. Cryptoderis.
Mouth of the perithecium recurved... 8. Camptospheeria.

264 THE FUNGL WHICH CAUSE PLANT DISEASE

Spores 2 or more-celled
Asci 8-spored

Spores elongate, 2 to 4-celled. ........ 9. Gromonia, p. 274.
Spores fusiform, curved, 2-celled. ..... 10. Hendersonia.
Asci many-spored; spores elongate,
2-celled
Perithecia beaked..................- 11. Rehmiella.
Perithecia not beaked. .............. 12. Rehmiellopsis, p. 276.

Ditopella de Notaris (p. 263)

Perithecia corticolous, covered, globose or somewhat depressed,
ostiole suberumpent; asci subclavate, polysporous; spores oblong
or fusoid, continuous, subhyaline; paraphyses none.

D. ditopa (Fr.) Schr. causes death of oak twigs in Europe;

D. fusarispora d. Not., occurs on alder in Europe.

Glomerella Spaulding & von Schrenk ** *4? (p. 263)

Perithecia cespitose, membranous, dark brown, rostrate, of a
lighter color at the apex in early stages, flask-shaped, hairy, on
or immersed in a stroma; asci sessile, clavate; spores 8, hyaline,
oblong, 1-celled, slightly curved, elliptic; paraphyses usually none.
Conidia=in part Colletotrichum and Gloeosporium.

This genus was first described by Stoneman, from perithecia
obtained from cultures of the conidia,?“’ as Gnomoniopsis. On ac-
count of preoccupation it wasrenamed Glomerella by Spaulding and
von Schrenk 7“ in 1903. Studies by Shear have shown that there
is much variation in pure line cultures both from ascospores and
from conidiospores.”” This leads to great uncertainty as to spe-
cific limitations as will become apparent in the paragraphs below.
The conidial forms are very common and are usually parasitic.
The ascigerous stages are comparatively rare. Sometimes they
are found in nature; again only in artificial culture. Some forms
known to be ascigerous may in one culture yield abundant peri-
thecia while other cultures of the same fungus may persistently
refuse to bear asci at all.

G. rufomaculans (Berk.) 8S. & 8.250259
Perithecia on decaying fruits, subspherical, more or less grouped;

THE FUNGI WHICH CAUSE PLANT DISEASE 265

asci subclavate, fugaceous, 55-70 yw; ascospores allantoid, 12-
22 x 3-5 yw; conidial stage (=Gleosporium rufomaculans) with
small sori, developing in more or less concentric circles, usually
soon rupturing and pushing out spores in small pinkish masses;
spores hyaline to greenish,
chiefly oblong, unicellular 10-
28 x 3.5-7 p.

The conidial stage of this
fungus was first described by
Rev. M. J. Berkeley in 1854
as a Septoria. It was later
transferred to the form genus
Gleeosporium under’ which
name the literature pertaining Fic. 193.—?. perithecium of G. rufomacu-

ee lans showing asci in situ; 6, asci show-
to it is largely to be found. ing detail. After Spaulding and von
See Southworth.2 The as- Scbrenk.
cigerous stage was found by Clinton *! in 1902 and the fungus
described as a Gnomoniopsis. In 1903, it was given the present
name. A bibliography of some one hundred eighty titles is
given by Spaulding and von Schrenk.?“8

The conidia germinating on apples send germ tubes through
the skin, usually through wounds, occasionally through a sound
surface.”>! The mycelium grows subepidermally, branching

rapidly, intercellularly and intracellularly,

(5. absorbing the sugar and other nutrients

present, and resulting in brown discolora-

é \ tion of cells and dissolution of their connec-
tion with neighboring cells. The mycelium
4 is first hyaline but later, especially in the

Fie. 194.—G. cactorum. stromata, it may be quite dark. Acervuli
Seaplane aaa soon appear, often in concentric rings, lift-
After Spaulding and ing the epidermis with their palisades of
ict aaAa conidiophores. The latter, at first hyaline,

later olivaceous, bear the numerous conidia, which are pinkish,

rarely cream-colored, in mass. In germination the conidia be-
come uniseptate and often on the tips of the young mycelium
develop the dark thick-walled irregularly shaped spore-like struc-
tures, so common on the sporelings of the Melanconiales. These

266 THE FUNGI WHICH CAUSE PLANT DISEASE

structures are regarded by Hasselbring 7°? as organs of attachment
to aid in infection, though they doubtless serve other purposes as
well.

Perithecia of this species were first obtained by Clinton 7°! who
grew them in abundance on artificial media from sowings of coni-
diospores taken from pure cultures. The typical Gloeosporium
stage was also grown from ascospores.

Perithecia were also found in pure cultures on apple agar by
Spaulding and von Schrenk. They appeared in black knotted
masses of mycelium which were often 4-5 mm. in diameter, the
perithecia varying from one to many in each such stroma. The
asci were evanescent, disappearing soon after the spores matured..

That this fungus is the cause of a limb canker was suggested by
Simpson’s discovery of the canker in July, 1902 and was definitely

proved by Spaulding
and von Schrenck,?*
and by Burrill and
Blair ** in the same
year.

In canker forma-
tion the mycelium
grows in the live
bark, killing it and
the cambium. The

a cankers are thought

Fic. 195——G. rufomaculans, germinating conidia. to be comparatively
Note septa and appressoria. After Spaulding and short lived, perhaps

von Schrenk.
surviving only the
third year. Reciprocal inoculations between fruit and twigs
have proved the fungus in the two cases to be identical. Conidia
and ascospores develop on both fruit and twigs.

The fungus has been repeatedly grown in pure culture on numer-
ous media by many investigators and many inoculations with
conidia into both fruit and twigs have proved the causal relation
of the fungus to the apple rot and twig canker. Inoculations from
ascosporic material have given the same results.

That the spores may be insect-borne was shown by Clinton; 75!
that they may also travel on the wind was shown by Burrill.?

THE FUNGI WHICH CAUSE PLANT DISEASE 267

The mycelium hibernates in limb cankers and in mummified
fruit.2°°

It is impossible morphologically to distinguish the conidial
stages of many species of Gleosporium and Colletotrichum grow-
ing on a great variety of hosts, and much inoculation work has
been done to ascertain the relationships existing between these
many forms. Thus the author“ in Dr. Halsted’s laboratory
made inoculations as indicated in Fig. 367. Southworth cross
inoculated a Gloeosporium from
grape to apple and from apple
to grape; Stoneman from
quince to apple.*"7 Even such
cultures give little evidence of
difference between these forms
and it usually is impossible to
distinguish between the conidial
forms on either morphological
or biological grounds.

Some group under Glomeralla
rufomaculans as its conidial
forms, what were formerly
known as Gloeosporium fructi-
genum, G. rufomaculans, G.
versicolor and G. leticolor.

Further studies of the ascig-
erous stages have led to con-
solidation rather than to seg-

. . Fic. 196.—Plate culture of G. rufomacu-
regation of species. Thus an lans showing. perithecia-bearing

j 2 masses. After Spaulding and von
ascigerous stage, a Glomer Be

ella, was obtained in pure
culture from the following conidial forms by Shear and
Wood: 78

G. rufomaculans from grape, G. fructigenum from apple, G.
sps. from cranberry, G. elastice from Ficus (see p. 544) a Gleo-
sporium from Gleditschia, one from Ginkgo, Colletotrichum
gossypii from cotton (see p. 271) and C. lindemuthianum. (See
p. 547) from bean. These authors after careful study of these
perithecia and cultures conclude that: ‘in the present state of

268 THE FUNGI WHICH CAUSE PLANT DISEASE

our knowledge, it may be best to regard the various forms we
have studied as varieties of one species.”

Among the hosts of G. rufomaculans may probably be num-
bered at least apple, grape, pear, quince, peach, tomato, egg-
plant, pepper, sweet pea 7° and cherry.”

G. rufomaculans var. cyclaminis P. & C.”°

Perithecia densely gregarious, indefinite, light-colored, around
spots, brown, membranous,
subglobose or distinctly ros-
trate, ostiolate; asci clavate-
cylindric, apex pointed, 50-
65 x 8-9 yu; spores oblong
to elliptic, 16-18 x 4-4.5 yu.

Conidia (=Colletotri-
chum); acervuli amphi-
genous, brownish, large;
conidia oblong to linear,
obovate, straight, or slightly
curved, ends round, 12-15 x
4-5 yw; conidiophores long,
slender; sete free, short,
rigid.

This variety is reported
on greenhouse Cyclamens,
causing leaf spotting. Ma-
: . ture perithecia were found
Fic. 197.—G. rufomaculans. Pustules on OD the leaves. Cultures

So uaeed: After Spaulding andvon from the ascospores gave a

Colletotrichum as the co-
nidial form and a similar Colletotrichum collected from the leaves
in pure culture gave the Glomerella.

G. cingulata (Atk.) 8. & S.

Perithecia cespitose, stromate, dark-brown, flask-shaped, mem-
branous, 250-320 x 150 yu, shortly rostrate, more or less hairy;
asci clavate, 64-16 y; spores hyaline, elliptic, slightly curved,
20-28 x 5-7 uy.

Conidia (=Gleeosporium cingulatum); acervuli 100-150 un,
rupturing the epidermis, in age black; conidiophores numerous,

THE FUNGI WHICH CAUSE PLANT DISEASE 269

crowded, simple, hyaline; conidia oblong to elliptic, straight or
curved, basally pointed, 10-20 x 5-7 yu.

This was first described in conidial form as a Glceosporium by
‘Atkinson *° on privet as cause of cankers. The fungus was isolated
and grown in pure culture. Later perithecia were obtained in
the pure cultures.?””

G. piperata (E. & E.) 8. & 8.

Perithecia cespitose, thinly membranous, dark-brown, pyriform,
hairy; asci clavate; spores slightly curved, elliptic, 12-18 x 4-6 uy.

Fig. 198.—Diagrammatic section through acervulus of G. rufomaculans.
a, parenchyma, }, cuticle, c, subhymenial fungous layer, d, conidiophores,
e, spores, 6, conidiophores and conidia in detail. After Clinton.

Conidia (=Gleeosporium piperatum) on circular or oval spots;
acervuli pustular, concentrically arranged, conidia 12-23 x 5-6 781

The ascigerous stage was grown from pure cultures of the conidia
taken from pepper by Miss Stoneman ™” the perithecia appearing
about a month after inoculation. Typical conidia were also se-
cured from ascospore sowings.

G. cincta. (B. & C.) 8S. & 8.8

Perithecia 180-280 uy, flask-shaped, membranous, cespitose;
asci clavate, truncate or obtuse, 65-70 yu; spores elliptic, curved,

5-20 x 3 p79
Acervuli erumpent; conidia (=Colletotrichum cinctum) 12-15 x

270 THE FUNGI WHICH CAUSE PLANT’ DISEASE

3-4 y, elliptic, guttulate; sete present, but almost obscured by
the spore mass.

The ascigerous stage was demonstrated by Stoneman 247 from
pure culture studies. The conidial stage was described by Hal-
sted 29 as the cause of a blighting of orchid leaves (Sobralia) in
New Jersey.

Various hosts are orchids, Sarracenia, rubber plant, Dracena
and Anthurium.?®

228

Fie. 199.—G. rufomaculans, acervulus showing conidia,
conidiophores and setae. After Hasselbring.

G. rubicola (Ston.) 8. & S.

Perithecia quite similar to those of G. piperata and G. cinta
but lacking the apical tuft of hair and rather larger in size.

Conidia (=Colletotrichum rubicolum) forming large, dark-
brown patches on the upper surface of the leaf; sori small, dark,
suberumpent; conidia oblong, elliptic, 12.5 x 6 u.

The conidial form on red raspberry was shown by Stoneman 2%”
by pure culture studies to possess this ascigerous stage.

G. psidii (Del.) Shel.76°-76+

Perithecia 200-300 y, spherical, rarely distinctly beaked; asci

THE FUNGI WHICH CAUSE PLANT DISEASE 271

cylindric to broadly clavate, blunt, 45-55 x 9-10 4; spores
curved, continuous, granular, 13-15 x 5-6 uy.

Conidia (=Glceosporium psidii), acervuli subepidermal on defi-
nite spots, 90-120 yw; conidiophores hyaline, cylindric, 15-18 x
4-5 yu; conidia elliptic, oval, hyaline, 10-13 x 4-6 un.

Artificial culture studies by Sheldon 7° 74 demonstrated the
ascigerous stage. Extensive study was made of the growth on

Fia. 200.—G. piperata, 99, perithecium external and in sec-
tion. 100, asci in detail. After Stoneman.

apple-agar, apples, plums, etc. Two distinct forms of conidia
were observed, one on loose hyphe, the other in acervuli. The
species should probably be regarded as a variety of G. rufo-
maculans.

It occurs on the guave.

G. gossypii (South.) Edg.

Perithecia distinct or crowded, very abundant, covered, dark
brown to black, subglobose to pyriform, 80-120 x 100-160 yh,
beak up to 60 » long; asci numerous, clavate, 55-70 x 10-14 yp;

272 THE FUNGI WHICH CAUSE PLANT DISEASE

spores elliptic, hyaline, rarely curved, 12-20 x 5-8 uw; paraphyses
long and slender, very abundant.

Conidia (=Colletotrichum gossypii), acervuli erumpent, coni-
diophores colorless, longer than the spores, 12-28 x 5 yw; conidia
irregularly oblong, hyaline or flesh-colored
in mass; sete single or tufted, dark at base,
colorless above, straight, rarely branched.

The conidial stage of this fungus was de-
scribed by Southworth ** 91 and independ-
ently by Atkinson 7” #1 3% on cotton.

The ascigerous stage was first seen by
Shear & Wood 2* in artificial culture and by
them regarded as probably a variety of G.
rufomaculans. Since these studies Edger-
ton 2% from examination of perithecia de-
veloped naturally in the open, has proposed
it as a separate species.

The mycelium is richly branched and sep-
tate, usually hyaline but sometimes slightly
Fic. 201.—G. gossypii, Smoky. It grows between and in the host

Section of young boll, cells which are often filled with it, causing

showing the fungus

penetrating the hull collapse, loss of chlorophyll, and browning.

Gee pe at kid Studies by Atkinson and by Barre * show

are being produced that in case of diseased bolls the mycelium

upon the outer por- ‘ 7
tion of the hull and may extend through the pericarp, sporing on

Ton ene uri cost its inner wall; extend thence to the seeds;

After Barre, penetrate and grow in them, Fig. 201, and in
the cells of the lint. Barre has shown that even the endosperm
and cotyledons may be invaded, Fig. 201, and spores produced
upon them while within the seed coats. Such seeds and lint may
appear outwardly as though perfectly normal.

The conidia are formed in acervuli, subtended by stromata.
Sete, from few to many increasing with age of the acervulus,
are present and conidia are occasionally found on them. In ger-
mination conidia usually develop one, sometimes two septa and
produce dark chlamydospores. Acervuli are common on bolls,
less so and smaller on leaves and stems.

The perithecia as found in the field by Edgerton in Louisiana

THE FUNGI WHICH CAUSE PLANT DISEASE 273

were usually entirely embedded, with the beaks only protruding
and were often numerous and crowded. Cultural evidence that
Edgerton’s specimens were actually genetically connected with
the cotton anthracnose are wanting.

The fungus has been repeatedly studied in pure culture and
numerous inoculations have thoroughly proved its pathogenicity,
the disease usually showing within
a few days after inoculation, though
sometimes incubation is delayed
much longer.

Infection of stems is often at a
wound such as a leaf scar; or on
leaves at some point of weakness.
Cotyledons and young plants are
especially susceptible. On bolls == ee
infection is common at the line Fic. 202.—G. gossypii, D, and E, fun-
of dehiscence of the carpels. Ac- US_£7Q¥ing in cotton lint fibers.
cording to Barre, there is evidence
that the fungus may destroy the contents of the boll before
it shows upon the outside. Barre showed that 44% of flowers
that received spores within ten hours after opening produced dis-
eased bolls; but inoculations by spraying produced no results on
bolls after they were three-fourths grown.

Seed from a field that bore 35% infected bolls gave on germina-
tion, 12% of infected seedlings, the disease appearing upon cotyle-
dons or hypocotyls even before they unfolded. Atkinson?” found
that conidia five months old were alive, but that at seven months
they failed to germinate. Barre also found the conidia and the
mycelium of the fungus to be comparatively short lived.

G. atrocarpi Del. on Atrocarpus leaves has been described as
a perfect stage of Glceosporium atrocarpi Del.

A fungus on Cattleya 7 7”? described by Maublanc & Lasnier
as a Physalospora should perhaps be considered as a Glomerella.

Gnomoniella Saccardo (p. 263)

Perithecia sunken and usually remaining so, with a long cylin-
dric, erumpent ostiole, leathery, black; asci ellipsoid or fusoid,

274 THE FUNGI WHICH CAUSE PLANT DISEASE

apically thickened and opening by a pore;
spore elliptic, 1-celled, hyaline; paraphyses
none.

This genus of some twenty-five species
~ contains G. tubiformis (Tode) Sacc. which
oa TT en is said to be the ascigerous stage of Lepto-

Winter. thyrium alneum Sacc. growing on Alder.
Two other species, G. fimbriata and G. coryli are found on

hornbeam and hazel respectively.

Gnomonia Cesati & de Notaris (p. 264)

Perithecia covered, or erumpent, submembranous, glabrous,
ostiole more or less elongate; asci ellipsoid or fusoid, apically thick-
ened, opening by a pore; spores elongate, hyaline, 2 to 4-celled;
paraphyses none.

There are somesixty species. Fusicoccum, Myxosporium, Sporo-
nema, Gleosporium, Marssonia, Asteroma, Leptothyrium occur in
some species as the conidial form. The ascigerous form usually
follows as a saprophyte after the parasitic conidial stage.

G. veneta (Sacc. & Speg.) Kleb.?7% 32%: 323, 335

Perithecia immersed, subglobose or slightly flattened, 150-
200 yu, short, rostrate; asci long-clavate, 48-60 x 12-15 y, gen-
erally bent at right angles at the base, apically very thick, opening
by a pore; spores 14-19 x 4-5, straight
or slightly curved, unequally 2-celled,
the upper cell longer.

Conidia variable in habitat, and
habit. (1) (=Glceosporium nervise-
quum) acervuli subcuticular 100-
300 4; conidiophores short, conidia
oozing out in a creamy-white mass, |,
hyaline, ellipsoid, 10-14 x 46 », (@
pointed at one end and rounded at the Me”
other. (2) (=G. platani) acervuli sub- Fie. 204—G. veneta, perithe-
epidermal, conidiophores long; conidia cium, After Edgerton.
as above. (3) ( =Discula platani=Myxosporium valsoideum) form-
ing minute, subepidermal, erumpent pustules on twigs; conidia
elliptic to oblong, hyaline, 8-14 x 4-6 y; (4) ( =Sporonema platani

THE FUNGI WHICH CAUSE PLANT DISEASE 275

=Fuscicoccum veronense). Pycnidia formed on old leaves on
the ground, erumpent, subcuticular, brown, 200-300 4; conidia
numerous, oblong, ovoid to fusoid, 7-11 x 3-4 p.

The conidial form on sycamore and oak, first described in 1848,
is common on leaves and young branches, the mycelium checking
the sap-flow and causing death of surround-
ing tissue. A stroma is formed on the outer
layers of the mesophyll and from this arise
the short conidiophores to constitute the
acervulus.

Infection experiments by Tavel 2 gave
negative results. Other infection experiments
have also been unsatisfactory.

The ascigerous form was first found by :
Klebahn ** on old leaves on which it ma- ie oe, ae Ed.
tured about Christmas time. While the co- gerton.
nidia are uniform in shape four modes of development are found,
as stated above.

Pure cultures from all the spore forms were compared by Edger-
ton *” confirming Klebahn’s conclusion as to their identity. Cul-
tures by Stoneman *” showed the forms on sycamore and oak to
be the same.

G. leptostyla (Fr.) Ces. & d. Not.

Perithecia conic, short-beaked; asci subclavate, 45-65 x 10-12
u; spores fusoid, curved, 18-22 x 4 yw, hyaline. Conidial phase
(=Marssonia juglandis). Acervuli gregarious, hypophyllous,
rounded; conidia obovoid, 8-10 x 4-5 uy, 1-septate, pointed
above, truncate below, greenish.

The connection between the conidial and ascigerous forms was
demonstrated by Klebahn ”* by pure cultures and by ascosporic
infection. The conidial form is common on walnut leaves; espe-
cially severe on the butter-nut (Juglans cinerea) often defoliating
this host in mid-summer.

G. quercus-ilicis Berl. occurs on oak leaves in Italy.

G. erythrostoma Auer. is the cause of a disease of cherry leaves
in Europe; 7 31

G. padicola Kleb. is the ascigerous stage of Asteroma padi
which is widely distributed in Europe on Prunus.

276 THE FUNGI WHICH CAUSE PLANT DISEASE

G. oryze Miy. occurs on rice.?”
G. rubi Rehm may occasionally cause disease of blackberry
canes.?%

Rehmiellopsis Bubak & Kabat (p. 264)

Similar to Rehmiella except that the perithecia are not beaked
and the pycnidia do not have a definite opening.

R. bohemica Bub. & Kab.; (conidia=Phoma bohemica) 7“ oc-
curs as a parasite on fir needles.

Clypeospheeriacez (p. 223)

Perithecia immersed, astromatic or with a pseudostroma built
of hyphe which, with the adjacent substratum, forms a thin cly-
peus that is usually evident only above; ostiole short to long-
beaked, erumpent, walls mostly carbonous to membranous;
paraphyses usually present.

A small family chiefly saprophytes.

Key to GENERA oF Clypeospheriacese

Spores 1-celled
Perithecia soft-membranous, spores hya-
line or brown...............0 eee 1. Trabutia.
Perithecia leathery; spores brown. ...... 2. Anthostomella, p. 276.

Spores more than one-celled
Spores with cross walls only
Spores cylindric, ellipsoid or fusiform

Spores hyaline, 1 to 3-septate...... 3. Hypospila.
Spores brown
Spores elongate. ..............4. 4. Clypeospheria.

Spores fusiform, more than 4
septate, sometimes muriform. 5. Phzopeltospharia.

Spores filiform, hyaline to yellow..... 6. Linospora.
Spores muriform
Spores ovate, brown... ............ . 7, Peltospheria.
Spores short, fusiform, hyaline....... 8. Isothea.
Anthostomella Saccardo

Mycelium fusing with the upper surface of the substratum to
form a thin, black, rounded pseudostroma; perithecia sunken, sub-

THE FUNGI WHICH CAUSE PLANT DISEASE 277

globose, with a short, conical ostiole, walls
black, carbonous to leathery; asci cylindric,
8-spored; spores elliptic, continuous, brown,
unappendaged; paraphyses usually present.
Over one hundred species, chiefly sapro- 3
phytes.
A. sulle Montem. occurs as the cause of a

leaf spot on sulla. Fic. 206.—A. des-
‘ . . 5 truens. 8, perithe-
A. bohiensis (Hmp.) Speg. is on cacao; cium; 9, apcuiks 10,
A. destruens Sh. on cranberry; spores; 11, germi-
937, 282 nating spore. After

A. coffee Desm. on coffee.?5” Shear.

Valsaceze (p. 223)

Stroma effused, subglobose, conic, or pulvinate, often indefinite;
perithecia sunken in the stroma, scattered or clustered, black,
leathery; asci cylindric or clavate; paraphyses usually present.

Over one thousand species, chiefly saprophytic. Conidia are
present on hyphe or in pycnidia.

Key To Genera oF Valsaceze

Spores 1-celled
Spores cylindric or ellipsoid, with a brown

membrane. ..........--.0-260-005 1. Anthostoma.
Spores ellipsoid, curved or not, with a
hyaline membrane. ............... 2. Valsa, p. 278.

Spores more than 1-celled
Spores with cross walls only
Spores hyaline
Spores unappendaged
Spores ellipsoid or fusoid 2 to 4-

celled... ......2--..20000 00s 3. Diaporthe, p. 278.
” Spores elongate, fusoid, constricted
in the middle............... 4. Vialaea.

Spores appendaged, 1 appendage at
each end and 2 or 3 in the mid-

le saco rs ale Adee ae 5. Caudospora.
Spores brown
Spores 2-celled, ellipsoid........... 6. Rhynchostoma.

Spores many-celled, fusoid......... 7. Kalmusia.

278 THE FUNGI WHICH CAUSE PLANT DISEASE

Spores muriform
Stroma effused

Spores hyaline ................... 8. Thyridella.
Spores colored. ................--. 9. Thyridium.
Stroma none or pulvinate............ 10. Fenestella.

Valsa Fries (p. 277)

Perithecia on a more or less definite stroma, immersed, the
ostiole erumpent, black, firm; asci globose to cylindric, often
long-pedunculate; spores
l1-celled, rarely 2-celled,
cylindric, rounded, hya-
line or light-brown; pa-
raphyses none.

V. leucostoma (Pers.)
Fr.2% 229, 280

Fic. 207.—Valsa. A, habit sketch; B, perithecia; Stroma strongly con-

C. asci. After Tulasne. vex, 2-3 mm., whitish
and granular within, outer layer coriaceous; perithecia immersed;
asci fusoid-clavate, subsessile, 35-45 x 7-8 u; spores biseriate,
allantoid, hyaline, slightly curved, 9-12 x 2-2.5 u.

Conidia (=Cytospora rubescens); stromate, erumpent, reddish;
conidia allantoid, 4 ». On pome and stone fruits throughout
Europe, Australia and America causing the disease known as
“dieback.” The fungus was studied by Rolfs 7 3*4 who worked
out its life cycle.

V. oxystoma Rehm. occurs on Alnus in Europe;

V. (Eutypa) caulivora Rehm. affects Hevea.

V. ambiens Fr. is on the apple in Europe.

V. (Eutypella) prunastri (Pers.) Fr. is the cause of serious dis-
eases of apples, plums, etc., in England.

V. (Eutypa) erumpens Mas. is reported as a wound parasite
in the tropics on Ficus, and cacao.

Diaporthe Nitschke (p. 277)

Stroma very variable, usually definite; perithecia membranous
subcoriaceous, generally pale-cinereous within, with a cylindric
or filiform beak; asci fusoid; spores fusoid to subelliptic, 2-celled,

THE FUNGI WHICH CAUSE PLANT DISEASE 279

hyaline, appendaged or not; pa-
raphyses none. Conidia=Phoma,
Cytospora, etc.

D. taleola (Fr.) Sace.

Stroma cortical, definite, de-
pressed, pulvinate, 2-4 mm., cov-
ered; perithecia few, 4-10, buried,
their ostioles converging, erumpent
in a small light-colored disk; asci
cylindric, 120-140 x 10-12 yu, spores
elliptic, uniseptate, constricted, with
setaceous appendages, 15-22 x
8-9 py.

It causes canker on oak, killing
the cortex over large areas. A
year later the cushion-like stromata
appear. The mycelium penetrates
both wood and bark, probably enter-
ing through wounds.

Fic. 208.—Diaporthe. B, stroma,
in section; C, asci. After Tu-
lasne.

D. albocarnis E. & E. on Cornus is destructive.
D. ambigua and D. sarmentella are on pear and hop, D. stru-
mella on a wide range of hosts, in conidial form as Phoma.

Melanconidacee (p. 223)

A small family of less than two hundred species contains only

four parasitic genera.

Stroma pulvinate, sunken; perithecia sunken in the stroma,
the mouth erumpent; asci cylindric or clavate; paraphyses present.

Key To THe GENERA OF Melanconidacee

Spores 1-celled, hyaline

Spores ellipsoid or short-fusiform. . . we
Spores elongate-cylindric, curved......

Spores 2-celled
Spores hyaline

Conidia in pycnidia; 1-celled, hyaline. .
Conidia not in pycnidia, dark brown. .
Spores brown. . ............ 00sec sees

1. Cryptosporella, p. 280.
2. Cryptospora.

3. Valsaria.
4. Melanconis, p. 281.
5. Melanconiella.

280 THE FUNGI WHICH CAUSE PLANT DISEASE

Spores more than 2-celled

Spores hyaline
Spores elongate, multicellular........ 6. Calospora, p. 280.
Spores fusiform, multicellular........ 7. Holstiella.

Spores brown
Spores elongate, multicellular; asci

8 or 4-spored.................-. 8. Pseudovalsa, p. 281.
Spores long-cylindric, very large, asci
Desporeds x se.no sets an ee eas 9. Titania

Calospora Saccardo

One species, C. vanilla Mas., reported as causing a Vanilla.
trouble, is perhaps identical with Gloeosporium vanilla C. & M.

Cryptosporella Tulasne (p. 279)

Stroma valsoid, pustuliform, covered; perithecia embedded,
subcircinate, with converging necks united in an erumpent disk;
asci cylindric to globoid; spores
elongate, cylindric, hyaline, 1-celled.

C. anomala (Pk.) Sacc.?“% 784

Pustules prominent, 2-5 mm.,
erumpent; penetrating the wood
and generally having a thin black
crust beneath them, disk convex or
slightly depressed, cinereous to black;
perithecia crowded, deeply em-
bedded in the stroma, often elon-
gate, ostioles scattered, black; asci
Fic. 209.—C. anomala. 31, stroma shove, a! Mesteous; teas hya-

and perithecia; 32, an ascus; 33, line, elliptic, simple, 7-8 x.

Paper Baten Sap hrey Common on hazel and filbert in
America, causing the destruction of the tops while the roots re-
main alive.

C. viticola Sh.°4

Pyenidia (=Fusicoccum) with labyrinthiform chambers, ostiolate
but frequently rupturing. Spores hyaline, continuous, of two forms
in the same cavity. 1. Subfusoid, 7.5 x 2-5 u.. 2. Long, slender,
curved, 18-80 x 1-1.5 4. Perithecia buried in irregular pulvinate

THE FUNGI WHICH CAUSE PLANT DISEASE 281

stromata, beak exserted; asci 60-72 x 7-8 ; paraphyses slender,
septate, wavy; ascospores subelliptic, hyaline, continuous, 11-15 x
4-6 uw. Fig. 210.

The conidial stage was described by Reddick as the cause of
necrosis of grape vines ®° though he has since stated that the
amount of damage due to this disease is not so great as at first
thought...

The ascigerous form in- pure culture in the hands of Shear *4
gave rise to the typical conidial form, identical with that grown
from pure cultures of the pycnospores.

Melanconis Tulasne (p. 279)

Stroma valsoid, seated in the substratum, partially erumpent;
perithecia clavate, immersed, with long cylindric beak; asci cylin-
dric, long-clavate, 8-spored; spores ellipsoid to elongate, hyaline.

About twenty species; chiefly saprophytes.

M. modonia Tul. in its conidial form (=Fusicoccum pernicio-
sum) causes a serious disease of the chestnut in Europe.*” #4

Pseudovalsa longipes (Tul.) Sacc. is parasitic on oak.

Diatrypacee (p. 223)

Stroma effused or pulvinate, built of thick hyphz, under the
peridium, at length erumpent, bearing both asci and conidia or
present only with the conidia; perithecia sunken in the stroma or
superficial, ostiolate; asci usually thickened apically; 4 to 8 or
many-spored; spores usually continuous, small, cylindric, curved.

About one hundred seventy-five species.

One parasitic genus occurs on cherry and plum.

Key To Tripes AND GENERA oF Diatrypacee

Stroma absent from ascosporic stage. ..... I. Calospheriex.
Asci 8 (rarely 4)-spored
Spores I-celled.. ....------.-2see eee 1. Calospheria, p. 282.
Spores 2-celled.. ........-----e eee 2. Cacospheria.
Asci many-spored. .........----+++00++ 3. Coronophora.

Stroma present in the ascosporic stage..... II. Diatrypex.

282 THE FUNGI WHICH CAUSE PLANT DISEASE

Calospheria. Tulasne (p. 281)

Perithecia astromate, free or on the inner bark, scattered or
clustered, ostiole more or less elongate; asci clavate, fasciculate;
spores small, cylindric, curved, hyaline, continuous; paraphyses
longer than the asci, stout lanceolate, evanescent.

About thirty-five species chiefly saprophytes.

C. princeps Tul.

Perithecia on the inner bark in orbicular or elliptic groups, gen-
erally densely crowded, globose, smooth and shining, necks long,

en
PRE

Fie. 210.—Crypto-

sporella_ viticola. ae. & ; 4

Asci and pa- Fic. 211.—Calospheria princeps. A, group of
raphyses. After perithecia; B, conidial stroma. After Tu-
Shear. lasne.

decumbent, flexuose, cylindric, erumpent; asci 12-26 x 4 u,
spores 5-6 x 1-5 uy.
On plum, cherry, peach and even pomaceous trees.

Melogrammataceze (p. 223)

Stroma usually pulvinate, rarely effused, hemispheric, sub-
peridial then erumpent and more or less superficial; perithecia
sunken in the stroma; conidia occur in acervuli on the surface of
the young stromata, or in pycnidia.

A small family of about one hundred twenty-five species, only
one genus of which contains important pathogens.

THE FUNGI WHICH CAUSE PLANT DISEASE 283

Key to Genera or Melogrammatacee

Spores 1-celled
Spores roundish ellipsoid, asci long fusi-
POTS ssc MRS be Fe aes a's on ee badaceibe 1. Gibelia.
Spores ellipsoid or ovate, asci clavate.... 2. Botryospheria, p. 283.
Spores 2 or more-celled
Spores with cross walls only
Spores 2-celled
Spores hyaline

Paraphyses present............. 3. Endothia.
Paraphyses absent.............. 4. Myrmeciella.

Spores brown... .................. 5. Myrmecium.

Spores more than 2-celled, ellipsoid to

filiform

Spores hyaline many-celled........ 6. Sillia.

Spores hyaline 3-celled............ 7. Melanops, p. 284.

Spores brown... ..............005. 8. Melogramma, p. 284.

Spores muriform...................... 9. Berlesiella.

Botryospheria Cesati & de Notaris

Stroma pulvinate, black; perithecia at first sunken in the stroma,
remaining so or becoming
more or less prominent,
usually small, globose, os-
tiole inconspicuous, papilli-
form; asci clavate; spores
elliptic to oval, hyaline,
continuous; paraphyses
present.

B. ribis G. &. Dug.”°

Stromata black, more or
less pulvinate, outer sur-
face botryose, 1-4 mm. in

: Fic. 212.—Botryospheria. B, stroma in sec-
diameter, usually 2-3 mm., tion; C, part of perithecium and pycnidium

in section. After Tulasne.

and surrounded by the
fissured periderm, regularly scattered or in more or less definite,
longitudinal rows or elongated stromata. Perithecia somewhat

284 THE FUNGI WHICH CAUSE PLANT DISEASE

top-shaped, with papillate ostioles and usually projecting, some-
times practically superficial. Few to many in a stroma and usually
interspersed among pycnidia; 175-250 » in width. Asci clavate,
80-120 x 17-20 yu, and with numerous filiform paraphyses.
Spores fusoid, continuous, hyaline, 16-23 x 5-7 yp.

Pycnidia of the compound stylosporic form, Dothiorella, are borne
in the same or similar stromata; spores fusoid, continuous, hyaline,.
18-31 x 4.5-8 ». Pycnidia of the simple stylosporic form, Macro-
phoma, are embedded in the outer bark under the much-raised
primary cortex of young shoots, depressed globular, 175-250 mm.
wide; spores fusoid, hyaline, continuous, 16-25 x 4.5-7.5 u.

The cause of a blight of canes of currants.

The fungus was first noted in sterile form by Fairchild.”* Its
history was first fully worked out by Grossenbacher & Duggar.”®
Extensive inoculation experiments and pure culture studies de-
finitely established its pathogenicity.

B. dothide Ces. & d. Not. causes epidemics of disease among
cultivated roses.™

B. gregaria Sacc. is injurious on willows in Europe.”

Melanops Fuckel (p. 283)

Stroma lens-shaped, black; perithecia sunken; asci elongate,
8-spored; spores elongate, 3-celled, hyaline; paraphyses elongate,
brown.

According to Shear,*“ the conidial stage of some members of
this genus is a Spheropsis which is indistinguishable from S. vitic-
ola and 8S. malorum.

Melogramma henriquetii Br. & Cav. is parasitic on cork oak.

Xylariacez (p. 224)

Stroma variable, usually free but often more or less sunken in
the matrix, either upright and often branched or horizontal, ef-
fused, crustaceous, pulvinate, globose or hemispheric, black or
becoming black, usually woody or carbonous; perithecia periph-
eral, immersed, leathery or carbonous, black; asci cylindric or
cylindric-clavate, 8-spored; spores continuous, brown or black,
fusiform or ellipsoid, paraphyses present or absent.

A family of over five hundred species.

THE FUNGI WHICH CAUSE PLANT DISEASE 285

Key to Genera or Xylariaceee

Stroma encrusted, shield-form, globose or

hemispheric, without a sterile base.... I. Hypoxylez.
Conidial layer beneath the surface of the
stroma, erumpent................. 1. Nummularia, p. 285.

Conidial layer free from the first
Stroma encrusted
Spores I-celled.. ................. 2. Bolinia.
Spores 2-celled.. ................. 3. Camarops.
Stroma discoid to hemispheric,’ en-
crusted together
Young stroma fleshy, covered by
conidia, at length carbonous... 4. Ustulina, p. 286.
Stroma carbonous or woody from the

first
Stroma without concentric layers. 5. Hypoxylon.
Stroma with concentric layers.... 6. Daldinia.
Stroma erect, simple or branched, clavate or
cylindric, with a sterile base.......... II. Xylariex.

Most of these genera are saprophytic on wood or bark.

Nummularia Tulasne

Stroma orbicular, cupulate or discoid, becoming black, mar-
ginate; perithecia monostichous, peripheral, immersed; asci cy-
lindric; spores subelliptic, continuous, dark.

The genus contains forty species. Only one is recorded as
injurious.

N. discreta (Schw.) Tul.

Stroma erumpent, orbicular, 2-4 mm., cupulate, with a thick
raised margin; ovate, cylindric, nearly 1 mm. long, abruptly con-
tracted above into a short neck; asci 110-120 x 10-12 yu; spores
subglobose, nearly hyaline, then opaque, 10-12 yp; paraphyses
filiform.

This fungus is usually a saprophyte but has been reported by
Hasselbring as a serious parasite on the apple in Illinois.*”

The mycelium grows more rapidly in the wood than in the bark,

286 THE FUNGI WHICH CAUSE PLANT DISEASE

attacking first the parenchyma cells and medullary rays. The
young stromata appear under the bark bearing when young small
unicellular-conidia. The stromata later turn hard and black and

pe
Fias. 213-214.—N. discreta, B, stroma and perithecia, C, a
perithecium, D. asci and spores. After Hasselbring.

in the upper layers bear numerous flask-shaped perithecia with
long necks, Figs. 213-214.

Ustulina Tulasne (p. 285)

Stroma superficial, subeffuse, rather thick, determinate, at first
clothed with a pulverulent cinereous conidial hymenium, finally
rigid, carbonous, black, bare and generally more or less hollow;

THE FUNGI WHICH CAUSE PLANT DISEASE 287

perithecia immersed, large, papillate-ostiolate; asci pedicellate,
8-spored; spores ovoid-fusiform; paraphyses present.

A genus of about ten species, chiefly saprophytes.

U. zonata Lev. is the cause of the commonest root disease of
tea and is common also on Hevea.

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288

BIBLIOGRAPHY OF ASCOMYCETES 289

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THE FUNGI WHICH CAUSE PLANT DISEASE

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8 Pammel, L. H., Iowa, B. 18: 921, 1891.

1 U.S. Dept. Agric. R. 352, 1888.

4° Salmon, E. S., Mon. Torr. Cl. 9: 36, 1910.

‘11 Vanha, J., Zeit. 14: 178, 1904.

BIBLIOGRAPHY OF ASCOMYCETES 291

112 Eriksson, J., Bot. Cent. 26: 335, 1886. a.

13 Fawcett, H. S., Fla. R. 40: 1909.

114 Palla, Ber. d. deut. Bot. Ges. 17: 64, 1899.

15 Farlow, W. G., Bull. Buss. Inst., 404, 1876.

116 Swingle, W. T. & Webber, H. J., V. P. P. B. 8: 25, 896.

117 Webber, H. J., V. P. P. B. 13: 1897.

8 Fawcett, H. S. & Rolfs P. H., Fla. B. 94.

us Fawcett, H.8., Univ. of Fla. Spec. Studies 1: 1908.

120 Seaver, F. J., Mycologia 1: 41, 1909, 177.

121 Aderhold & Ruhland, Arb. a. d. Biol. Abt. f. Land. u. Forst am Kais.
Gesund. 4: 429, 1905.

122 Tdem, 2: 48, 1909-1910.

123 Berlese, A. N., Riv. d. Pat. Veg. 5: 88, 1897.

124 Boeuf, F., B. d. Dir. d. L’Ag. et d. Comm. Tunis, 27: 1903, also 1905.

125 Paddock, W., N. Y. (Geneva) B. 163: 204, 1899.

128 Durand, E. J., N. Y. (Cornell) B. 125: 1897.

127 Grossenbacher, J. G., & Duggar, B. M., N. Y. (Geneva) T. B. 78:
1911.

128 Mayer, H., Unt. forst bot. Inst. Miinchen 3: 1, 1888.

129 Halsted, B. D., N. J. R. 12: 281, 1891; and 359, 1894.

130 Massee, Kew Bul. Jan. and Feb., 1899.

131 Thssen, G., C. Bak. 27: 48, May, 1910.

1322 Smith, E. F., B. V. P. P. 17: 1899.

133 Higgins, B. B., Sc. 31: 916, 1910.

134 Higgins, B. B., N. C. R. 32: 100, 1910.

1385 Butler, Mem. Dept. Agric. India, Bot. Ser. 2: 9, 1910.

136 Zimmermann, A., C. Bak. 8: 148.

137 Petch, T., Cire. & Ag. Jour. Roy. Bot. Gard. Ceylon, Nov., 1910.

138 Selby, A. D. and Manns, T. F., Ohio B. 203.

139 Selby, A. D., Ohio B. 97: 40, 1898.

140 Sorakin, N., Zeit. 1: 238, 1891.

141 Cavara, Zeit. 3: 16, 1893.

142 Noack, F., Zeit. 10: 327, 1900.

143 Petch, T., Cire. & Ag. J. Roy. Bot. Gard. Ceylon, 8: 65, 1910.

144 Frank, Ber. deut. Bot. Ges. 1: 58, 1883.

45 Atkinson, G. F., J. Myc. 11: 248, 1905.

148 Miyake, Bot. Mag. Tokyo Ag. 1908.

47 Williams, T. A., 8. D. B. 83: 38.

148 Stager, R., Bot. Zeit. 111, 1903.

149 Stevens, F. L., & Hall, J. G., Bot. Gaz. 50: 460, 1910.

180 Brefeld, O., Untersuch. 12: 194.

292 THE FUNGI WHICH CAUSE PLANT DISEASE

151 Fulton, H. R., La. B. 105: 17, 1908.

152 Patterson, F., and Charles, V. K., B. P. I. 171: 9, 1910.

153 Lodeman, IE. G., N. Y. (Cornell) B. 81: 1894.

454 Farlow, W. G., Bul. Bussey Inst., 440, 1876.

165 Beach, §. A., N. Y. (Geneva) B. 40: 25, 1894.

186 Humphrey, J. E., Mass. R. 8: 200, 1891.

187 Garman, H., Ky. B. 80: 250, 1899.

168 Schweinitz, Syn. Fung. Carol. Sap. 134.

189 Ruhland, W., C. Bak. 12: 250, 1904.

10 Cooke, M. C., Grevillea 13: 63.

161 Clevenger, I. T., Jour. Myc. 11: 160, 1905.

102 Hohnel, F. von, Sitz, K. Akad. Wis. Vienna Math. Nat. Kl. 118:
813.

183 Shear, C. L., B. P. I. B. 110 and Torr. Bul. 34: 305.

14 Wakker & Went. De Sietleen von het suikerriet op Java, 153: 1898.

168"Massee, Ann. Bot. 7: 515, 1893.

166 Massee, Ann. Bot. 10: 583, 1896.

17 Hartig, Hedw. 12: 1888; Allegm. Forst. u. Jagd,—Zeit. Jan. 1884.

18 Tubeuf, Bot. Cent. 41: 1890.

19 Hartig, Hedw. 12: 1888.

70 Stewart, F. C. & Blodgett, F. H., N. Y. (Geneva) B. 167: 1899.

™ Pierce, N. B., V. P. P. B. 164: 1892. °

1 Viala, Pourridie d. Vignes et d. Arbres fruitiers.

vs Prillieux, C. R. 185: 275, 1902.

4 Behrens, J., C. Bak. 3: 584,'1897.

178 Whitson, E. P., Sandsten et al, Wis. R. 21: 237.

1% Schrenk, H. von, B. P. I. B. 36: 1903.

17 Hedgcock, R. Mo. Bot. Gard. 17: 59, 1906.

78 Heald, F. D. & Wolf, F. A., Mycologia 2: 205, 1910.

1 Tubeuf, C. von, Zeit. 3: 142, 1893.

© Vuillemin, Jour. de Bot. 1: 315, 1888; 2: 255, 1890.

181 Smith, R. E., Cal. B. 191: 1907.

1? Viala & Ravaz, Prog. Agr. Et. Vit. 9: 490, 188.

Viala & Ravaz, B. Soc. Myc. d. Fr. 8: 63, 1892.

184 Jaczewski, A. von, Zeit. 10: 257, 1900.

* Scribner, F. L., U. S. Dept. Agric. R. 109, 1886.

18 Rathay, E., Zeit. 306, 1891.

187 Chester, F. D., Del. B. 6: 1889.

8 Shear, C. L., Miles, G. F., Hawkins, L. A., B. P. I. B. 155: 1909.

18 Price, R. H., Texas B. 23: 1892.

0 Reddick, D., N. Y. (Cornell) B. 293: 1911.

BIBLIOGRAPHY OF ASCOMYCETES 293

191 Prillieux, B., Soc. M. d. Fr. 4: 59, 1888.

192 Shear, C. L., B. P. I. B. 710: 15, 1907.

193 Prillieux & Delacroix, C. R. 130: 298, 1900.

194 Shear, C. L., Bul. Torr. Bot. Club, 34: 305, 1907.

198 Shear, C. L., Bul. B. P. I. B. 110.

1% Bernard, Ch., Bul. Depot Agric. Ind. Neerland 6: 1907.

197 Seribner, U. 8. Dept. Agr. R. 334, 1887.

18 Dudley, W. R., N. Y. (Cornell) B. 14: 1889.

199 Pammel, L. H., Ia. B. 13: 70, 1891.

20 Stewart, F. C. & Eustace, H. J., N. Y. (Geneva) B. 2296: 356,
1902.

201 Aderhold, Ber. d. deut. Bot. Ges. 18: 242, 1900.

202 Klebahn, H., Zeit. 18: 5, 1908.

203 Duggar, B. M., N. Y. (Cornell) B. 145: 1898.

204 Atkinson, G. F., Garden & Forest 10: 73, 1897.

205 Grossenbacher, J. G., N. Y. (Geneva), T. B. 9: 1909.

206 Jour. Bd. Agr. London, 17: 215.

207 Zeit. 3: 90; 4: 138, Frank, C. Bak. 5: 197, 1899.

28 Halsted, B. D., N. J. B. 107 and Bul. Mye. Fr. 7: 15, 1891.

209 Potebnia, A., Ann. Myc. 8: 58, 1910.

210 Hedgcock, G. G., J. Myc. 10: 2, 1904.

211 Jaczewski, Bull. Acad. Sc. Cracow 1892, 1893, 1294.

212 Cobb, N. A., Hawaii B. 5: 93, 1906, Sugar Planters Expt. Sta.

218 Atkinson, G. F., O. E. 8. B. 33: 308. 1896.

214 Atkinson, G. F., Bul. Torrey Bot. Cl. 18: 1891.

218 Scribner, F. L., U.S. Dept. Agr. R. 355, 1887.

216 Atkinson, G. F., Ala. B. 41: 1893.

217 Atkinson, G. F., Bot. Gaz. 16: 61, 1891.

218 Stewart, F. C., B. 328: 389, 1910.

219 Halsted, B. D., N. J. R. 381, 1893.

220 Rostrup, Tid. f. Skw. 17: 37, 1905.

221 Notizblatt k. Botan. Gart. u. Mus. Berlin-Dahlem 4: 297, 1907.

222 Voligno, Ann. R. Acad. Agric. Torino 48: 417, 1905.

223 Rathay, E., Zeit. 4: 190, 1894.

224 Johnson, J., Proc. Ry. Dublin Soc. N. 8. 10: 153.

228 Pyjllieux and Delacroix, Bull. Soc. M. d. Fr. 6: 113.

228 Maublanc and Lasnier, Bull. Soc. M. d. Fr. 20: 167, 1904.

227 Rev. in E. 8. R. 13: 259.

228 Sheldon, J. L., J. Myc. 13: 138.

229 Smith, E. F., J. Mye. 7: 36, 1891.

230 Lawrence, W. H., Wash. B. 64: 1904.

294 THE FUNGI WHICH CAUSE PLANT DISEASE

231 Aderhold, R., Landw. Jahr. 25: 875, 1896.

232 Clinton, G. P., Ill. B. 67: 1901.

233 Aderholdt, R., C. Bak. 6: 593, 1900.

234 Vuilleman, C. R. 108: 632, 1889.

235 Cavara, Zeit. 3: 16, 1893.

236 Frank, B., Zeit. 5: 10, 1895.

237 Delacroix, G., Agr. Prat. Pays chauds, 7: 235, 1907.

238 Wagner, Zeit. 5: 101, 1895.

239 Qudemans, C. A., J. A. Proc. Soc. Sci. Konin. Akad. Wet. Amster-
dam 3: 141.

240 Halsted, B. D., N. J. R. 13: 290, 1892.

241 Pammel, L. H., Ia. B. 116: 1910.

212 Diedicke, C. Bak. 9: 317, 1902, and 11: 52, 1904.

243 Ravn, F. K., Zeit. 11: 1, 1901, and Zeit. 17: 13, 1901.

244 Noack, Zeit. 15: 193, 1905.

245 Viala and Ravaz, Rev. d. Vit. 197, 1894.

246 Bubak, Nat. Zeit. f. For. u. Land. 8: 313.

247 Stoneman, B., Bot. Gaz. 26.

248 Spaulding and von Schrenk, B. P. I. B. 44: 1903.

249 Shear, C. L., Sc. 32: 808. 1910.

260 Southworth, E. A., J. Myc. 6: 164, 1891.

251 Clinton, G. P., Ill. B. 69: 1902.

252 Hasselbring, H., Bot. Gaz. 42: 135, 1906.

83 Burrill, T. J. and Blair, J. C., Ill. B. 77: 1902.

264 Burrill, T. J., Sc. 16: 909, 1902, and Ill. B. 118: 578, 1907.

265 Hasselbring, H., Trans. Ill. Hort. Soc. 36: 350, 1902.

256 Sheldon, J. L., Sc. 22: 51, 1905.

257 Osterwalder, A., C. Bak. 11: 225, 1904.

258 Shear, C. L. and Wood, A. K., Bot. Gaz. 43: 259, 1907.

259 Patterson, F. W. and Charles, V. K., B. P..I. B. 171: 1910.

20 Atkinson, G. F., N. Y. (Cornell) B. 49: 310, 1892.

21 Halsted, B. D., N. J. R. 11: 1890.

2 Edgerton, C. W., Bot. Gaz. 45: 404, 1908.

283 Sheldon, J. L., Se. 21: 148, 1905.

284 Sheldon, J. L., W. Va. B. 104: 1906.

»85 Southworth, E. A., J. Myc. 6: 100, 1890.

266 Humphrey, J. E., Zeit. 1: 174, 1891.

267 Atkinson, G. F., J. Myc. 6: 172, 1890.

28 Edgerton, C. W., Mycol. 1: 115, 1909.

9 Barre, H. W., 8. C. R. 22: 1909.

270 Atkinson, G. F., O. E. 8. B. 33: 1896.

BIBLIOGRAPHY OF ASCOMYCETES 295

271 Bul. Sc. Myc. de France 18: 285, 1902.

272 Tdem., 20: 167, 1904.

273 Tavel, F., J. Myc. 5: 53, 1889.

274 Klebahn, H., J. Wis. Bot. 41: 515, 1905.

276 Klebahn, C. Bak. 15: 336, 1905.

276 Frank, B., Zeit. 1: 17, 1891.

277 Miyake, Bot. Mag. Tokyo 23: 1909.

278 Edgerton, C. W., Bul. Tor. Bot. Cl. 34: 593.
279 Rolfs, F. M., Se. 26: 87, 1907.

0 Rant, A., Zeit. 17: 177, 1907.

381 Montemartini, L., Riv. Path. Veg. 4: 165, 1910.
282 Delacroix, G., Bull. Soc. M. d. France, 20: 142, 1904.
283 Massee, Kew Bull. June, 1892.

284 Humphrey, J. C., Mass. R. 10: 242, 1893.

285 Grossenbacher, J. G. and Duggar, B. M., N. Y. (Geneva) B. 18: 1911.
26 Fairchild, D. G., Bot. Gaz. 16: 262, 1891.

287 Hasselbring, H., Ill. B. 70: 225, 1902.

288 Butler, E. J., Ann. Myc. 9: 36, 1911.

289 Fulefeld, Natw. Zeit. F. & Land. 8: 527, 1910.
290 Woronin, M. & Nawaschin, S., Zeit. 6: 129, 1896.
291 Muller-Thiirgau, C. Bak. 6: 653, 1900.

292 Tkeno, Flora, 92: 1, 1903.

293 Quaintance, A. L., Ga. B. 50: 1900.

204 Cordley, A. B., Ore. B. 57: 1899.

295 Galloway, B. T., D. Ag. R. 349, 1888.

298 Potebnia, A., Ann. Myc. 8: 79, 1910.

297 Edgerton, C. W., Mycologia 2: 169, 1910.

298 Clinton, G. P., Ct. R. 319, 1906.

299 Spaulding, P., B. P. I. Cire. 35.

300 Zimmerman; A., C. Bak. 8: 183, 1902.

301 Miyake, I., Bot. Mag. 21: 1, 1907.

302 Egsed, Ann. Bot. 25: 343, 1911.

303 Essed, Ann. Bot. 25: 364, 1911.

304 Pissed, Ann. Bot. 25: 367, 1911.

305 Miyake, I., Bot. Mag. 23: 1909.

306 Hegy, P., B. Soc. M. d. Fr. 27: 155, 1911.

307 Ducomet, V., Ann. Ec. Nat. Agr. Rennes 2: 1.
308 Potebnia, A. Ann. Myc. 8: 48, 1910.

309 Potebnia, A., Ann. Myc. 8: 70, 1910.

310 Halsted, B. D., N. J. R. 358, 1893.

311 Rand, F, V., Phyto. 1: 133, 1911.

296 THE FUNGI WHICH CAUSE PLANT DISEASE

312 Duggar, B. M., N. Y. (Cornell) B. 745: 1898.

313 Scribner, F. L., U.S. D. Agr. R. 341, 1887.

314 Stewart, F. C., N. Y. (Geneva), B. 328: 387, 1910.

315 Clinton, G. P. Ct., R. 307, 1906.

316 Heald, F. D., Sc. 29: 624, 1906.

317 Richardson, A. E. V., Jour. Dept. Agr. So. Aust. 14: 466.

318 U.S. Dept. Agr. R. 129, 1886.

319 Atkinson, G. F., Ala. B. 41: 1893.

320 Atkinson, G. F., O. E. S. B. 33: 293, 1896.

321 Southworth, E. A., Dept. Agr. R. 407, 1890.

322 Edgerton, C. W., Bot. Gaz. 45: 367, 1908.

323 Galloway, B, T., U. S. Dept. Agr. R. 387, 1888.

3% Shear, C. L., Phytop. 1: 116, 1911.

325 Reddick, D., N. Y. (Cornell) B. 263: 13, 1909, and Reddick, D.,
Phytop. 1: 106, 1911.

328 Griffon, E. and Maublane, A., C. R. Se. (Paris) 151: 1149, 1910.

327 Sadebeck, Unt. ti die Pilsegall, 1884.

328 Metcalf, H., B. P. I. B. 121: IV, 1908.

329 Metcalf, H., & Collins, J. F., B. P. I. B. 141: 5, 1909.

330 Appel, see C. Bak. 11: 148.

331 Stewart, F. C., N. Y. (Geneva) B. 328: 318, 1910.

332 Appel O. & Wallenweber, H. W., Arb. d. Kais. Biol Anst. f. Land
Forst. 8: Heft, 1, 1910.

333 Bernard, C., Bul. Dept. Agr. Indes, Neerl. 55, 1907.

334 Rolfs, F. M., Mo. Fruit B. 17: 1910.

335 N. Y. (Cornell) B. 15: 1889.

336 Atkinson, G. F., Bul. Torrey Bot. Club 21: 224, and Bot. Gaz.
16: 282, 1891.

337 Noack, F., Zeit. 9: 18, 1899.

3% McAlpine, D., Dept. Agr. Melborne 132, 1899. °

339 Zimmerman, A., C. Bak. 8: 148, 1898.

3 See Arnaud, G., Ann. Myc. 8: 471, 1910.

41 Ann. Mye. 8: 472, 1910.

342 Sheldon, J. L., Sc. 23: 851, 1906.

43 Pammel, L. H., Proc. Ia. Acad. Se. 7: 177, 1899.

*“4 Parker, J. B., Ohio Naturalist, 9: 509, 1909.

*46 Griffon & Maublanc, B. S. M. d. Fr. 26: 371, 1910.

546 Shear, C. L., Sc. 31: 748, 1910.

57 Murrill, W. A., Torreya, 6: 189, 1906.

48 Stone, G. E. & Smith, R. E., Mass. R. 57, 1901.

349 Larsen, L. D. H., Sug. Pl. Assn. B. 10.

BIBLIOGRAPHY OF ASCOMYCETES 297

360 Aderhold, R., Landw. Jahr. 25: 875, 1896 and 29: 541, 1900.

351 Brooks, F. J., Ann. Bot. 24: 285, 1910.

382 Prillieux, E. and Delacroix, G., Bul. Soc. M. d. France, 9. 269,
1893.

363 Bull. Soc. My. d. Fr. 14: 24, 1898.

354 Brefeld, Unt. 9.

BASIDIOMYCETES (p. 64)4%743° 43: 50° 5

This class is distinguished from all others by its basidium, which
typically is a sporophore bearing on its distal end short stalks,
the sterigmata, usually four,
on which are borne spores,
basidiospores, one on the
tip of each sterigma, Fig.
215. In the great ma-
jority of genera the basidia
are typical and are clearly
recognizable as such.

In many of the lower
basidiomycetes the basidia
deviate somewhat from the
typical form. Thus in the
Hemibasidii, the smut
fungi, the basidia are not
typical in that they always
arise from chlamydospores,
not directly from the my-
Fic. 215.—The typical basidium with sterig- celium, Figs. 217, 231, and

wicimeate Ree en stages of de- that they may produce more

than the normal number
of four sporidia and these often from lateral, not terminal
sterigmata.

The basidia in the large group of rust fungi are also atypical.
The mycelium of the Basidiomycetes is septate and branched,
and is always well developed. It is often found invading cells
several meters from the sporogenous structures and frequently
weaves together to form rhizomorphs.

Peculiar cell connections known as clamp connections, or knee
joints, Fig. 287, are often found. The basidia in many genera are

298

THE FUNGI WHICH CAUSE PLANT DISEASE 299

borne on large complex sporophores composed of the mycelial

threads interwoven to form a false
parenchyma. The spores may
germinate by tubes or by bud-
ding.

Typical sexuality seems en-
tirely wanting, even rudimentary
or vestigial sexual organs, cer-
tainly recognizable, have not been
found. The group is supposed in
this regard, to represent the results
of extreme simplification; the sex-
ual organs to have long ago dis-

Fic. 216.—Ustilago spores showing
development. After De Bary.

appeared and the simple nuclear fusions that now exist to serve

functionally as fertilization.

Kery To THE SUBCLASSES OF Basidiomycetes

Chlamydospores at maturity free in a
sorus, produced intercalary, from
the mycelium; basidiospores borne
on a promycelium and simulating
CONIA? 6. eka ee hud edad eda ees

Chlamydospores absent or when present
borne on definite stalks

Basidia septate, arising from a rest-
ing spore or borne directly on
a hymenium.................
Basidia nonseptate, borne on a hy-
menium. ..............00008-

1. Hemibasidii, p. 299.

2. Protobasidii, p. 323.

3. Eubasidii, p. 393.

Hemibasidii

The Hemibasidii contain one order.

Ustilaginales

45, 47, 124, 126-129, 131, 137

Parasitic fungi, smut producers, mycelium consisting of hyaline,
somewhat septate, branched, mostly intercellular filaments,
practically limited to the interior of the host; at maturity often

300 THE FUNGI WHICH CAUSE PLANT DISEASE

disappearing partially or wholly through gelatinization; fertile my-
celium compacting into masses and giving rise to numerous chlam-
ydospores formed from its contents. Conidia rarely develop on
the exterior of the host. Sori prominent, usually forming dusty or
agglutinated spore-masses that break out in definite places on the
host or more rarely remain permanently embedded in the tissues.
Spores (chlamydospores) light to dark colored, single, in pairs,
or in spore-balls, the latter often composed in part of sterile cells.

‘The Ustilaginales are all parasites on higher flowering plants.
The vegetative mycelium is mostly inconspicuous and is often

cums eave

Fic. 217.—Ustilago. 2, promycelium with nucleus in mi-
tosis; 5, with 4 nuclei; 6, with conidia. After Harper.

distributed very widely in the host plant without giving external
evidence of its presence until time of spore formation. It sends
variously formed botryose or spherical haustoria into the host
cells. At time of maturity of the fungus, the mycelium develops
in great abundance at certain special places in the host, often in
the ovary, leading to the development of large mycelial structures
in the place of the host tissue.

The chlamydospores develop directly from the vegetative my-
celium; new and numerous transverse cell-walls are formed; the
resulting short cells swell, round off and become coated with a
gelatinous envelope. This later disappears and the spores develop
a new, thick, usually dark, double wall which is variously marked.

THE FUNGI WHICH CAUSE PLANT DISEASE 301

The chlamydospores may be simple or compound, fertile or in
part sterile and are variously shaped and marked as described in
the genera below.

The chlamydospores may germinate at once or after a more or
less protracted rest interval. In germination in water or nutrient
solution (manure water, etc.) a short tube is protruded, the pro-
mycelium, this differing in character in the two families, Figs. 217,
231. From the promycelium of most species there develop conidia,
(often called sporidia) 1-12 or even more. The promycelium is
regarded as homologous with the basidium of the other basidio-
mycetes and the conidia as basidiospores.

The conidia in suitable nutrient solutions often undergo repeated
and indefinite budding closely simulating yeast cells in appearance.
Fusion of conidia is not uncommon.
Fig. 218. Conidia finding lodgment
in suitable plant parts under suitable
environmental conditions give rise to
infection. The points at which in-
fection can occur are very diverse
with different species and will be
considered under the separate species
below. z aus ie

The vegetative cells are binucleate We eg ae
in Tilletia, multinucleate in the Usti- Wijh Insion tue, aptea cons
laginaceze.4%° The young chlamydo-
spores were shown by Dangeard *!!5 in the case of Doassansia,
Entyloma, Ustilago and Urocystis to be binucleate. These two
nuclei, according to Dangeard, later fuse rendering the mature
spore uninucleate. In germination the one nucleus passes into
the promycelium, then divides mitotically Fig. 217, 2. A second
division gives four nuclei (Fig. 217, 5) the spore nuclei.*

In the fusions of smut conidia Federly has found an accom-
panying nuclear fusion, in salsify smut, while Lutman finds similar
fusion in the conjugating promycelial cells of oat smut.*

Whether or not these nuclear fusions represent a sexual act is
a much controverted point.

There are according to Clinton about four hundred species in

America® 24

¢
302 THE FUNGI WHICH CAUSE PLANT DISEASE

Key to Famiuies or Ustilaginales

Promycelium usually with sporidia lateral

ab Bepta.. .garckaussans sees OSTREAM S 1. Ustilaginacee, p. 302.
Promycelium with clustered terminal
BPOTICIA sd. ciee code sun aseetine san etees 2. Tilletiaceee, p. 314.
Ustilaginacee

Sori usually forming exposed dusty or agglutinated spore-
masses. Germination of chlamydospores by means of septate
promycelia which give rise to terminal and lateral sporidia or else
to infection-threads.

Key to Genzra or Ustilaginacee

Spores single
Sori dusty at maturity
Without definite false membrane..... 1. Ustilago, p. 303.
With false membrane of definite fungous
CASS iia Hdleecrn cae xity stele taias 2. Sphacelotheca, p. 310.

Sori agglutinated at maturity
Firmly agglutinated into conspicuous

tubercular nodules.............. 3. Melanopsichium.
Developed around a central columella
(rarely dusty).............0c 000s 4, Cintractia.
Spores chiefly in pairs
Sori agglutinated (on leaves)........... 5. Schizonella.
Sori dusty (inside peduncles). .......... 6. Mykosyrinx.

Spores in balls of more than two
Sori dusty or granular
Spore-balls often evanescent; spores
olive-brown or black-brown. ..... 7. Sorosporium, p. 312.
Spore-balls rather permanent; spores
yellowish or reddish, with markings
only on free surface............. 8. Thecaphora, p. 313.
Spore-balls quite permanent; spores ad-
hering by folds or thickenings of
outer coat... ..............0000. 9. Tolyposporium, p. 313

THE FUNGI WHICH CAUSE PLANT DISEASE 303

Sori agglutinated
Spore-balls (variable) composed of

thick-walled spores.............. 10. Tolyposporella.
Spore-balls with peripheral spores and
central sterile cells.............. 11. Testicularia.

Of these genera numbers three to eleven inclusive occur on un-
important plants. Among them are: Polygonum, Rynchospora,
Psilocary, Cyperus, Carex, Luzula, Juncus, Fimbrystylis, Cissis;
various unimportant grasses, members of the Carduacez, Faba-
cee, Nyctaginaceez, Amarantacee, Cyperacer, Dracenacex, and
Eriocaulaceez. The most important genera are Ustilago and
Sphacelotheca.

Ustilago (Persoon) Roussel (p. 302)

Sori on various parts of the hosts, at maturity forming dusty
spore masses, usually dark colored; spores single, produced irregu-
larly in the fertile mycelial threads which early entirely disappear
through gelatinization, small to medium in size; germination by
means of a septate promycelium producing only infection-threads
or with sporidia formed terminally and laterally near the septa;
sporidia in water usually germinate into infection-threads but in
nutrient solutions multiply indefinitely, yeast-
fashion.

About two hundred species, seventy-two of
which are given by Clinton® as occurring in
America. Besides the species discussed below
many others occurring upon grasses or other
plants of minor value are omitted.

U. avenz (Pers.) Jens.24 116 117, 124, 12

Sori in spikelets, rarely in leaves, forming a
dusty olive-brown spore-mass, about 6-12 mm. Fis. 219.—U. ave-

« ne, germinating
long by half as wide, usually rather completely in water. After
destroying floral parts, eventually becoming dissi- Stem
pated; spores lighter colored on one side, subspherical to spherical
though often elongate, minutely echinulate, 5-9 y» in length,
widespread on oats.

The fungus was known by the name Ustilago as early as 1552

304 THE FUNGI WHICH CAUSE PLANT DISEASE

and was called U. avene in 1591. The species of Ustilago
on oats, wheat and barley were considered identical until
Jensen ® showed that they are not intercommunicable. Wolff ®
showed that seedlings can be infected through the first’ sheath
leaf. Brefeld’ studying infection more closely found it to be
accomplished by germ tubes from sporidia and that plants are
free from infection after the growing leaves have pushed one
centimeter through the sheath leaf. The mycelium, after infec-
tion, grows through ‘the plant until blooming time when it seeks
the ovaries and the enclosing glumes in which it forms a mycelial
mass, which soon changes into spores. In nutrient solutions the
conidia bud indefinitely, while on the host plant they produce
infecting hyphe.
Germination was first studied by Prévost.2 It occurs read-
: ily in water, a well de
veloped promycelium
resulting in about
twenty-four hours,
Fig. 219. The sporidia
are mostly narrowly
elliptical. Fusion of
sporidia is common.
The promycelia are
usually four-celled and
occasionally branch,
especially near the
base. [138 126
U. crameri Korn."
Sori in the spikelets,
infecting all of the
spike, ovate, about
24 mm. in length,
: . chiefly destroying in-
"Such enlarged, ‘showing emut myedium. Atier er and basal parts:
agen spores reddish-brown,
chiefly ovoid to subspherical though occasionally more elongate
and irregular, smooth, with usually pitted contents, chiefly 8-11 p
in length.

THE FUNGI WHICH CAUSE PLANT DISEASE 305

The promycelium is much branched but no sporidia are pro-
duced.

The smut commonly affects the ovaries of Panicum and Setaria.
In America it has been collected on millet in several states.

U. crus-galli T. & E.15?

Sori often encircling stems at nodes or at the juncture of the
inflorescence, infecting both stem and leaves, prominent, often
nodular, one to several centimeters in length, protected by a tough
hispid membrane which upon rupture discloses an olive-brown
dusty spore-mass; spores ovoid to spherical, occasionally more
elongate, rather bluntly echinulate or even verruculose, chiefly
10-14 yp in length.

On Panicum crus-galli throughout the United States.

U. bulgarica Bub. is on Sorghum vulgare. European.

U. medians Bieden, on barley, is closely like U. hordei.1®

U. scorzonere (A. & S.) Schr. on Scorzonera is very close to
U. tragopogonis-pratensis.

U. sacchari Rab.*4

Spore-mass black, spores globose or angularly globose, 8-18
in diameter, olive-brown or rufous, epispore thick, smooth.

On sugar-cane throughout the tropics, especially in the old
world.

In Java this fungus has been reported as the cause of serious
damage. Barrett observed it in Trinidad, where the damage was
less extensive.

The leaves especially the young ones which have not yet sepa-
rated from each other are the parts affected. From the upper part
of the affected cane, as a rule, no secondary shoots arise, and those
which do arise from the lower part become infected in their turn.
The discolored whip-like structure at the end of an attacked cane
becomes dusty and black and contains the spores of the fungus.

U. hordei (Pers.) K. é& 8.24 11% 184

Sori in spikelets, forming an adhering purple-black spore-mass,
about 6-10 mm. in length, covered rather permanently by the trans-
parent basal parts of the glumes; spores lighter colored on one side,
usually subspherical or spherical, smooth, 5-9 u, the most elongate
rarely 9-11 » in length. Common on barley.

This was first recognized as distinct from the oat smut in 1591

306 THE FUNGI WHICH CAUSE PLANT DISEASE

by Lobelius.!° Persoon in 1801 first gave a definitely recognizable
description.!! In 1888 the species was separated from the other
smut on barley."

The spores germinate freely in water by one, rarely two, tubes,
usually 4-celled, and produce abundant sporidia; these increase by
budding, produce germ tubes, or fuse with each other.

U. levis (K. & S.) Mag.*# 48

Sori in spikelets, forming a black-brown adhering spore-mass,

sometimes small and entirely concealed by the

3 glumes but usually evident and destroying inner

and basal parts; spores lighter colored on one side,

subspherical to spherical or rarely elongate, smooth,
5-9 p, the most elongate rarely 11 y in length.

On oats throughout America and Europe, prob-
ably more common than records show as’ it is very
difficult to distinguish from U. avene from which
it differs chiefly in its smooth granular spores.

U. macrospora Desm.

Sori in leaves and glumes, generally showing as
linear striae, but often more or less merged, at
first covered by the epidermis, but this later rup-
turing and disclosing black-brown dusty lines of:
gp a itl Lp spores; spores medium to dark reddish-brown,

tion in modi- chiefly ovoid to spherical or occasionally some-

fied Cohn’s :

solution. Af- What irregular and elongate, coarsely verrucose, at

ter Clinton. Gireumference usually showing .the projections as
tinted blunt scale-like appendages, sometimes even semi-reticulate,
12-19 » in length.

On various species of Agropyron in Europe and America.

U. nuda (Jens.) K. & 8.2% 16

Sori in spikelets, forming a dusty olive-brown spore-mass, about
6-10 mm. long by half as wide, temporarily protected by a thin
membrane which soon becomes dissipated leaving the naked rachis
behind; spores lighter colored on oné side, minutely echinulate,
subspherical to spherical or occasionally elongate, 5-9 u in length.

In Europe and America. This smut on barley is distinguishable
from the covered smut, U. hordei, by its olive-green spore-mass
and by its early shedding of spores. As a rule, each spikelet, ex-

THE FUNGI WHICH CAUSE PLANT DISEASE 307

cept the awn and rachis is entirely transformed into smut. In
water and in nutrient solutions the spores germinate by a single
promycelium, 1 to 3-septate, and often branched, but without
sporidia. That infection is floral in loose smut of both wheat and
barley was first shown by Maddox ™ and the fact was corrob-
orated by Wakagawa,'* Brefeld'© and Hecke.’ The my-
celium has been demonstrated in the embryo by Broili.1”3

The spores falling between the glumes germinate, penetrate
the ovary wall, and into the growing point of the embryo. The
mycelium here lies dormant until the seed germinates, when it
grows, keeping pace with the growing point throughout the season
and finally invading the ovaries to produce its spores.

The infection of the pistil, the penetration of the integuments
and the nucellus and embryo sac was followed in microtome sec-
tions by Lang.!22_ The embryo was reached by the mycelium some
four weeks after infection of the pistil. In resting grains the my-
celium is abundant in the scutellum as well as in
all embryo parts except the roots.

Cross inoculation by Freeman and Johnson ®
from barley to wheat and the reverse gave
negative results. The optimum time for infec-
tion has been determined as the period of full
bloom.

U. perennans Rost.?*4 454

Sori in spikelets, more or less destroying the -

5 : . Fic. 222.—0U. tritici,
basal and inner parts, sometimes even running ~ germination in
down on pedicels, oblong, about 3-8 mm. in ™odified Cobn’s
length, with dusty, olive-brown spore masses; Kellerman and

: . ‘ . Swingle.
mycelium perennial in perennial parts of host;
spores chiefly subspherical or spherical, occasionally ovate to el-
lipsoidal, usually lighter colored on one side, more or less
minutely echinulate, especially on the lighter side, 5-8 » in
length.

On the tall oat grass throughout its range.

U. rabenhorstiana Kiihn occurs on several species of Panicum.

U. tritici (Pers.) Rost.?4 16 124 125, 128

Sori in spikelets, forming a dusty olive-brown spore-mass, about
8-12 mm. long by half as wide, usually entirely destroying floral

asta

308 THE FUNGI WHICH CAUSE PLANT DISEASE

parts and eventually becoming dissipated and leaving behind only
the naked rachis; spores lighter colored on one side, usually sub-
spherical to spherical, occasionally elongate, minutely echinulate
especially on the lighter side, 5-9 u in length. On wheat where-
ever cultivated.

The smut mass is covered at first by a very delicate membrane.
Infection is floral as described for U. nuda.

The spores germinate in water by a long 2 to 3, or even 6 to
7-septate, promycelium, often curved. In nutrient solutions the

Re.
Fia. 223.—U. zew, stages in spore development. After Knowles.

promycelium branches profusely but sporidia are few or are en-
tirely absent.

U. zee (Beck.) Ung.1% 24 119-121 133, 136, 142

Sori on any part of the corn plant usually prominent, forming
irregular swellings from a few millimeters to over a decimeter in
diameter, at first protected by a sort of false white membrane
composed of plant cells and semi-gelatinized fungous threads,
soon rupturing and disclosing a reddish-brown spore-mass; spores
ellipsoidal to spherical or rarely more irregular, prominently
though rather bluntly echinulate, 8-11 » the most elongate 15 u
in length.

The germination of the spores, which occurs but poorly in water,
was first studied by Kihn ™ in 1857. In 1874 Kihn saw the pene-
tration of the germ tubes through the epidermis of the corn plant.
Brefeld showed that the spores germinate well in nutrient- solu-
tions and that secondary spores are formed; also that corn can be
infected by the sporidia at any point on its surface above ground

THE FUNGI WHICH CAUSE PLANT DISEASE 309

when the tissues are soft and actively growing; and that infection
is local on the host.2!

It is now known that the chlamydospores are capable of ger-
mination without hibernation and that they remain viable one,
two, perhaps more
years. It was shown
by Brefeld in “1895
that the chlamydo-
spores produce conidia
in the air freely. It 4
is these, air-borne,
arising from spores
on the ground, ma-
nure, etc., which are
chiefly responsible for
infection. They must
reach the plant on a
susceptible part and
under suitable con-
ditions of moisture.
The germ tubes from
the conidia penetrate
the epidermis, grow
through or between
the cells, Fig. 223,

: Fic. 224.—U. zex. 1, germination after three days in
with an irregular my- water; 2, similar but in air showing air sporidia.

celium which branches “““* Clinton.

profusely and calls forth great hypertrophy of the surrounding
host tissue. In sporing, the mycelium forms a great number of
short, slender, irregular branches which make up a close tangled
network in the diseased tissue. These slender branches swell,
gelatinize, and portions of them round off as spores, Fig. 223.

U. strieformis (West.) Niess.?* 15

Sori in leaves, sheaths and rarely in the inflorescence, from short
to linear, often extending, apparently by terminal fusion, for
several centimeters, also occasionally fusing laterally to cover most
of the leaf; at first covered by the epidermis but this is soon rup-
tured and dusty brown to black, linear masses of spores become

310 THE FUNGI WHICH CAUSE PLANT DISEASE

scattered and the leaves become shredded; spores usually ellip-
soidal to spherical, occasionally irregular, prominently echinulate,
chiefly 9-14 » in length.

It appears to be perennial. The spores germinate sparsely.
The promycelium is long, branched, septate, and produces no
conidia. ;

On numerous species of grass, including red top, timothy and
species of Poa and Festuca throughout Europe and America.

Species of less importance, not all found in America are:

U. schiriana Hem. which attacks bamboo; ”

U. secalis Rab. is European on rye; possibly a Tilletia.

U. esculenta P. Hen. which causes swellings on Zizania which
are eaten in the orient;

U. vaillantii Tul. in the sexual organs of the Liliacez;

U. panici-miliacei (Pers.) Wint. on Panicum miliaceum;

U. tragopogi-pratensis (Pers.) Wint. on the flowers of Trago-
pogon;

U. cruenta Kiihn, widespread in Europe on sorghum;

U. violacea (Pers.) Fel. on the anthers of various members of
the Caryophyllacez;

U. tulipz Wint. on tulips and related hosts;

U. vrieseana Vuill. on eucalyptus roots, a very doubtful species;

U. spherogena Burr. on Panicum crus-galli.

The fungus described as U. fischeri Pers. from Italy on corn
is a Sterigmatocystis as is also U. phoenicis Corda on date fruits
and U. ficuum Reich on figs.

Sphacelotheca De Bary (p. 302)

Sori usually in the inflorescence, often limited to the ovaries,
provided with a definite, more or less temporary, false membrane,
covering a dusty spore-mass; and a central columella, usually
formed chiefly of the host plant’s tissues. The false membrane
is composed largely or entirely of sterile fungous cells which are
hyaline or slightly tinted, oblong to spherical, and usually more
or less firmly bound together; spores single, usually reddish-brown,
developed in a somewhat centripetal manner as in Cintractia,
small to medium in size; germination as in Ustilago.

Sixteen species are recorded by Clinton for America. Of these

THE FUNGI WHICH CAUSE PLANT DISEASE 311

only three are of economic importance. By Engler and Prantl, the
genus is not separated from Ustilago.

Sphacelotheca sorghi (Lk.) C.2% 24 128 136 144

Sori usually in the ovaries or stamens forming oblong to ovate
bodies 3-12 mm. in length (rarely fusing the very young spikelets
into irregular forms), protected for
some time by a false membrane Bee NEA AS
upon the rupture of which the SRO Lo Se eer aay
olive-brown spore-mass becomes
scattered, leaving naked: the dis-
tinct columella of plant tissue.
The sterile cells of the membrane
break up to some extent into
groups, hyaline, oblong to sub-

spherical, chiefly 7-18 yw in length ; 20° O8 Pn bit
spores subspherical to spherical, "is SS SA
smooth, contents often granular, ‘ye ny iibgty
5.5—8.5 u in diameter. NT a heed

On Johnson grass and sorghum vara getie
throughout the world. The young NA
pistil and usually the stamens as INA
well are displaced by the fungous Nat yay
mycelium, the two being often Veet
blended together. The spores ger- CHEB
minate readily in water, either

. . 225.—S. sorghi, cross-section
when fresh or a year old, showing ee cs i age i ecton

papille in from three to ten hours. Pedy ever 2 a fake oe
The promycelium is 2 to 3-septate celium, 6, mature spores, b’, im-
and from the ends of one or more —_@ature spores, ¢, columella. After
of its cells narrow tubes appear.
These later fuse with the adjacent cell, forming the ¢‘buckle
joints.” Either infection tubes or sporidia may also arise from
the promycelium. Infection is possible only with young plants.
The mycelium in the host plant grows rapidly into long irregu-
lar, hyaline, thin-walled threads 2-4 mm. thick, which run through
and between the cells. It is most abundant in the parenchyma,
advancing especially through the pith region with the growth of

the host. The young ovaries and stamens are eventually reached

312 THE FUNGI WHICH CAUSE PLANT DISEASE

and the mycelium there develops richly under the epidermis. The
outer cells remain sterile and constitute the membrane; the inner
gelatinize and develop into spores.
S. reiliana (Kiihn) Cl.?# 11% 15 141 126
Sori very prominent forming irregular masses including more or
. less of the entire panicle, usually
5-15 cm. in length; often at first pro-
tected by the leaf-sheath. A whitish
false membrane encloses - the black-
brown spore-mass and the ray-like re-
mains of the peduncles or columellas.
In time it becomes ruptured and the
; spores scattered. Sterile cells are also
Fic. 226.—S. reiliana. Ger- Scattered in groups through the spore-
reppin eee a eet, After - mass, chiefly subspherical, 7-15 y in
diameter; spores somewhat opaque,
chiefly subspherical to spherical or occasionally ovoid or slightly
angled, minutely but abundantly verruculose, 9-14 » in length.
This is a cosmopolitan but comparatively rare form on corn,
affecting the ovaries. It occurs also on sorghum. In germination
a 3 to 4-celled, often branched, promycelium is formed and conidia
are produced.
S. diplospora (E. & E.) Cl. is found on Panicum crus-galli and
related grasses in the lower Mississippi Valley.

Sorosporium Rudolphi (p. 302)

Sori in various parts of the ‘host, forming dusty, dark colored
spore-masses; spore-balls of medium size com-
posed of numerous fertile cells, often rather
loosely united and frequently at maturity com-
pletely separating; spores usually olive or
reddish-brown, of medium size; germination
similar to that of Ustilago; sometimes with
elongate germ thread and no sporidia. Tie: 4 Zeanenpes

Several species are parasitic on the coarser rium. Spore mass.
range grasses. S. consanguineum E. & E., coe
S. everhartii Ell. & Gall., and S. ellisii Winter, are probably the
Most important. S. dianthi Rab. is found on Dianthus.

THE FUNGI WHICH CAUSE PLANT DISEASE 313

Thecaphora Fingerhuth (p. 302)

Sori in various parts of the host, often as indefinite masses in
the floral parts or forming rather firm pustules on the stem, at ma-
turity with a dusty spore-
mass; spore-balls composed
of few to many fertile cells,
of small to large size; rather
permanently united; spores
usually yellowish or reddish,
smooth on contiguous sides Fi. 228.—Thecaphora, spore ball germina-
but usually marked on the tion. After Brefeld.
free surface; germination, so far as known, by means of a single
sporidium at the tip of the elongate septate promycelium.

A small genus of slight economic importance.

T. deformans Dur. & M.1%% 12

Sori in the seeds, showing when the legumes are broken open
as reddish-brown, dusty spore-masses which destroy most of the
seeds; spore-balls reddish-brown, ovoid to spherical, rather firm,
composed of 3-25 (usually 7-12) spores, chiefly 27-60 u in length;
spores in optical section triangular to polygonal or when free
irregular oblong, free surface with papille that sometimes vary to
spiny processes, 15-25 yu, chiefly 15-20 u in length.

On a large number of Leguminous hosts, including species of
Vicia, Lathyrus, Lupinus, Trifolium, etc., in widely scattered
regions of both the old and the new world.

Tolyposporium Woronin (p. 302)

Sori usually in the inflorescence, especially the ovary, forming
granular spore-masses at maturity; spore-balls dark-colored, of
numerous spores permanently united, germination about as in
Ustilago.

A genus of about ten species.

T. bullatum Schr.!% 154

Sori in ovaries, infecting occasional ones, ovate, about 3-5 mm.
in length, covered with a thin, greenish, smooth membrane, upon
rupture of which the black granular spore-mass becomes scattered ;

314 THE FUNGI WHICH CAUSE PLANT DISEASE

spore-balls black, opaque, oblong
to spherical or polyhedral, usually
containing one hundred or more
firmly agglutinated spores, chiefly
50-180 » in length; spores from
nearly hyaline, to light reddish-
brown, outer coat more or less
folded in ridges, often spiny, ovoid
to subspherical or polyhedral,
chiefly 7-10 » or rarely 12 » in
Fia. 229.—Tolyposporium. Spore length.

ball germination. After Brefeld. Ads Panteuin crus-galli aa the
United States east of the Rocky Mountains also in Europe.

T. filiferum and T. volkensii, occur on sorghum in Africa.

Tilletiaceze (p. 302)

Sori either forming dusty erumpent spore-masses or permanently
embedded in the tissues. Germination by means of a short promy-
celium which usually gives rise to a terminal cluster of elongate
sporidia, that, with or without fusing in pairs, produce similar
or dissimilar secondary sporidia or germinate directly into infection
threads.

The American Tilletiaceee embrace nine genera and about one
hundred twenty-five species.

Key to Genera oF Tilletiacee
Spores single
Sori dusty at maturity
Spores without a conspicuous hyaline

appendage..................004 1. Tilletia, p. 315.
Spores with an elongate hyaline append-
GBOs Bisa cra sccieuet al ones ented 2. Neovossia.
Sori permanently embedded in the tissues
Sori definite, small.................. 3. Entyloma, p. 320.
Sori indefinite, large................. 4. Melanotenium.
Spores in balls
Sori dusty; spore-balls with sterile cor-
tex

ieee Runa d atGee ee Mla Sara nana tele 5. Urocystis, p. 318.

THE FUNGI WHICH CAUSE PLANT DISEASE 315

Sori rather permanently embedded in
tissues

Spore-balls without sterile cortex
Spore-balls consisting entirely of

dark-colored spores. ........ 6. Tuburcinia.
Spore-balls consisting of light-colored
spores
Spore-balls with or without central
sterile cells. ................ 7. Burrillia.
Spore-balls with central network of
HilaMENntS 9 5 Oe. o ic Mad Pare aeons 8. Tracya.
Spore-balls with sterile cortex. ...... 9. Doassansia, p. 322.

Neovossia occurs on Phragmites; Tuburcinia on Convallariacee,
Primula, Trientalis and Geranium in Russia; Burrillia on Limnan-
themum, Echinodorus and Sagittaria; Tracya on Spirodela.

Tilletia Tulasne ° (p. 314)

Sori in various parts of the hosts, usually in the ovaries, forming
dusty spore-masses; spores single and usually formed singly in
the ends of the mycelial threads
which disappear more or less
completely through gelatiniza-
tion, germination usually by a
short promycelium which bears
a terminal cluster of elongate
sporidia that in nutrient solu-
tions, with or without fusing in
pairs, may give rise to a con-
siderable mycelium bearing sec-
ondary air-sporidia.

The genus closely resembles : Sy
Ustilago except in its larger Fic. 230.—T. fcetens, spores. Photo-

: : micrograph. After Clinton.
spores and mode of germination.

Twenty-two American species are listed by Clinton. Only three
are of economic importance.

T. pancicii Bub. & Ran. is reported on barley heads in Servia.”*

T. glomerulata. Cocc. & Mor. is a doubtful species on alfalfa.

316 THE FUNGI WHICH CAUSE PLANT DISEASE

T. feetens. (B. & C.) Trel.2* 12 12% 15

Sori in ovaries, ovate or oblong, 5-8 mm. in length, more or
less concealed by the glumes, all or only part of the ovaries of
a spike infected; spores light to dark-brown, oblong to chiefly sub-
spherical or spherical, occasionally somewhat angular, foetid, es-
pecially when young, smooth, chiefly 16-22 u, the most elongate
rarely 28 yw in length.

On wheat wherever grown.

Kiihn % found that infection occurs as in oats in the very
young plants. From the infection point
the mycelium approaches the growing
point and follows the development of
its host, sending its branches into each
spikelet and finally into the growing
ovules. Here it develops a close knot
and in the ends of the threads and in the
short branches the spores form. The
spores germinate by a rather long, con-
tinuous, thick promycelium on the tip of
which a crown of long slender conidia de-
velops. The sporidia soon become arched
and often fuse in pairs; they develop in-
fection threads.

Fic. 231.—T. foetens. 4, T. tritici (Beij.) Wint.1%

[gece ight ap aan a Sori in ovaries, ovate to oblong, 5-8 mm.

which have united. One in length, more or less concealed by the

has produced a secondary ‘ 3
sporidium at X and thisis glumes; sterile cells few, hyaline, sub-

sending out an infection spherical, with medium-thin wall, smaller

and Stedman. than the fertile cells which are chiefly
subspherical, light to dark-brown, with winged reticulations
about 1 » high by 2-4 » wide, and 16-22 » in diameter.

On wheat everywhere.

Experiments have shown this distinct from T. foetans which it
closely resembles except for its reticulate spores.

T. texana Long: Cl.!” :

Sori in ovaries, ovoid or oblong, about 3-5 mm. in length, more
or less hidden by enveloping glumes, forming a somewhat agglu-
tinated light-reddish-brown spore-mass; sterile cells not very

——

wars

: ?
ee =
=

oo

THE FUNGI WHICH CAUSE PLANT DISEASE 317

numerous, hyaline, with very thick, often lamellate walls; fertile
cells very light colored, orange-yellow appearing as if immature,
chiefly subspherical or spherical, with prominent conical tubercles
which extend out 2-3 u to the hyaline envelope, chiefly 19-25 »
in diameter (including envelope.)

On Hordeum nodosum in Texas.

T. hordei Keke is an Asiatic form on Hordeum.

T. secalis (Cda.) Kuhn. occurs on rye in Europe.?

T. horrida Tak.2& 121 149

Sori in the ovaries more or less destroying them, completely

oY B
Fic. 232.—Tilletia tritici. 4. Two spores germinated in
moist air, promycelium and conidia, several of which have
fused in pairs. Secondary conidia at C. B. Spores ger-
minated in water, promycelia elongate, septate. The pro-
toplasm passes over into the younger cells. After Tubeuf.

concealed by enveloping glumes; spores usually present in different
stages of development, the mature spores almost opaque, chiefly
subspherical to spherical, with very coarse hyaline or slightly
tinted, somewhat curved, scales which show at the circumference
of the spore as a band about 24 » wide and on its top as polyg-
onal areas 2-3 yw across; hyaline membrane more or less evident
and often at one side in a short thread-like projection, 22-33 u
in length.

Cross sections of stems bearing smutted heads reveal the my-
celium in the chlorophyll parenchyma between the fibrous tissue.”

On rice in America and Asia.

318 THE FUNGI WHICH CAUSE PLANT DISEASE

Urocystis Rabenhorst ! (p. 314)

Sori usually in the leaves or stems, occasionally in other parts,
producing dark-colored, usually dusty, spore-masses;

& ‘© spore-balls permanent, composed of an enveloping
‘ “Sf cortex of tinted sterile cells and usually one to

Fic. 233.—Spore several interior fertile cells; fertile cells generally

balls of U. ce- y a
pulz. After dark-colored; germination often by a short promyce-

etd lium which pro-
duces terminally-grouped spori- J
dia; these give rise to similar
secondary sporidia or to infec-
tion-threads.
Besides the forms discussed
below, foreign species are listed
on Anemone, Liliacer, Gladiolus, *

Primula, etc. FR
U. cepulz Frost.2” % 180 146 4 \ ;
Sori in leaves, forming isolated = = \
pustules or affecting them for \-
the greater part of their length w (/\ sae { I
and breadth, sometimes occur- TX })

ring at their bases, in the bulbs.
Upon rupture of the covering t f V f a
membrane a dusty black-brown HL.
spore-mass appears; spore-balls 7
ovoid to spherical, 17-25 mw in “a " Dee,
length; sterile cells tinted, ovoid « y
to spherical, small, rather com- y ia
pletely covering the spores, jy aS %
usually 4-8 » in length; fertile AN
cells reddish-brown, ovoid to Pte,
spherical, usually 1, rarely 2 in a :
a ball, chiefly 12-16 p in length, "nating, 2 grecgt, V5q¢ebule germi
On Alitam, conidium. After Thaxter.
The first American description of the fungus was by Farlow 2
in 1876. A second thorough paper was from Thaxter in 1889.2"
The mycelium grows between the host cells. At maturity lateral

THE FUNGI WHICH CAUSE PLANT DISEASE 319

outgrowths appear from the hyphe at various points. One of
these assumes a somewhat spherical form and matures to the fertile
spore, while the other branch or branches grow around it, Fig. 235,
branching and dividing into joints which eventually round off to
form the sterile exterior cells. Spores are
known to live in soil for at least twelve years.” =
A period of rest is necessary before they can
germinate. In germination the central spore
produces a single short hypha, commonly
branched, on which the conidia are borne ter-
minally and laterally. Fig. 234. Experiments
by Thaxter indicate that infection is subter-
ranean.
U. occulta (Wal.) Rab.}% 151 Pe
Sori in leaves, especially in the sheaths, Fic. 235.—Successive
culms and inflorescence, forming linear striz rear ares
usually of great length and often merged into et Thaxter.
a continuous stratum of dusty, reddish-black, spore-balls; spore-
balls oblong to subspherical, 16-32 p» in length; sterile cells
often incompletely covering the spores, hyaline or yellowish, sub-
spherical to oblong, usually with distended and uniformly thick-
ened walls; fertile cells reddish-brown, oblong to subspherical,
often flattened, smooth, 1 to 4 in a ball, 11-18 yu in length.
On rye wherever cultivated, though not common in America.
The seat of spore formation is most often on the stems or sheaths,
though all aérial parts of the plant are susceptible. In the vege-
tative parts the fungus is commonly found in
the tissue between the vascular bundles.
U. viola (Sow.) F. de W.!% 14% 150
35 Sori on stems, rootstocks, petioles and leaves
forming prominent irregular swellings often sev-
KE etna a ip oc. eral centimeters in length, rather permanently
culta. After covered by the host tissues but upon rupture
Thaxter. : “
disclosing black-brown spore-masses; spore-balls
reddish-brown, rather irregular, oblong to subspherical, chiefly
28-55 uw in length; sterile cells yellowish-tinted with age, 6-10 u
in length; fertile cells light reddish-brown, ovoid to spherical or
polyhedral, chiefly 4-8 in a ball, mostly 11-15 yu in length.

320 THE FUNGI WHICH CAUSE PLANT DISEASE

On violets. In America it has been reported in Canada, Min-
nesota and Utah.

U. anemones (Pers.) Wint.!“ occurs on various species of Ranun-
culacez in both the old and new world.

U. agropyri (Preu.) Schr.®

Sori in various parts, commonly in leaves, forming striz, which
may be distinct or cover the surface of the leaf; at first lead-colored
and protected by the epidermis but soon rupturing and scatter-
ing the reddish-brown spores; spore-balls oblong to subspherical,
16-32 » in length; sterile cells hyaline to yellowish, oblong to
subspherical, usually completely covering the fertile cells, outer
wall thin and by collapsing giving a ridged effect to the covering;
spores 1 or 2, rarely 3 or 4 in a ball, reddish-brown, oblong to sub-
spherical, often flattened, smooth, 11-18 u in length.

On Agropyron and some other coarse grasses throughout the
United States and Europe.

U. colchici (Sch!.) Rab.!2 On various species of Liliacee but
not on hosts of economic importance in America.

U. italica Speg. probably not a true smut, is injurious to
acorns, chestnuts and the seeds of the white fir.”

Species of less importance or non-American are:

U. gladioli (Req.) Sm. on Gladiolus;

U. ornithogali K6érn. on Ornithogalum;

U. kemetiana Mag. in pansy ovaries;

U. primulicola Mag. on primrose flowers.

Entyloma De Bary 18” 14 (p. 314)

Sori usually foliar, generally forming discolored but not distorted
areas, permanently embedded: in the tissues; spores single, pro-
duced terminally or intercalary in the mycelium which does not
entirely disappear through gelatinization, free (sometimes irregu-
larly adhering through pressure), hyaline to yellowish or reddish-
yellow, rarely dark-colored, germination by a short promycelium
bearing a terminal group of sporidia which usually conjugate in
pairs and produce secondary sporidia or infection-threads; sporidia
often formed by germination of the spores in situ, the promycelium
protruding through the stomata.

Twenty American species are recorded.

THE FUNGI WHICH CAUSE PLANT DISEASE 321

Foreign species are on Papaver, Ranunculus, Delphinium, Calen-
dula, Thalictrum and several other hosts.

E. betiphilum Bub. is described on beet seed capsules; *°

E. lephroideum for the same host in France;

E. calendule (Oud.) de B. on Calendula.

E. crastophilum Sacc.°®

Sori in leaves, subcircular to linear, about 0.25-2 mm. in length,
usually distinct though occasionally merged, black, long covered
by ‘the epidermis; spores dark-brown, tightly packed and adhering

a y mae ue

Fic. 237.—E. ellisii, dhissnydompores germinating within
the leaf tissue, sporidia superficial. After Halsted.

more or less, chiefly ovoid to spherical or angled through pressure,
rather thick-walled, 8-14 yu in length.

On Poa, Phleum, Agrostis and other grasses in Europe and
America.

E. irregulare Joh. occurs on species of Poa in Europe and
America;

E. polysporum (Pk.) Farl. on various hosts including the com-
mon sunflower.

E. ellisii Hals.*!

Sori in leaves, forming pale white spots, indefinitely limited,
subconfluent; spores hyaline or slightly yellowish, clustered in the
intercellular spaces beneath the stomata, spherical, thick-walled,
(2-5 p) chiefly 16-20 u» but varying from 11 to 25 uw in diameter;
conidia hypophyllous, abundant, acicular, small, 10-14 yu by less
than 1 pu.

On spinach, New Jersey.3" 15°

The chlamydospores germinate in situ beneath the stomata
and bear the sporidia on tufts of promycelia which emerge through
the stomata, presenting much the appearance of a Hyphomycete.

322 THE FUNGI WHICH CAUSE PLANT DISEASE

E. australe Speg.

Sori foliar, forming spots, yellowish to eventually dark, usually
0.5-6 mm. in length; spores light to reddish-yellow, ovoid to
spherical or slightly angled, chiefly 10-16 y» in length; conidia
linear, somewhat curved, usually 30-55 x 1-2 u.

Common and destructive on many species of Physalis and on
Solanum, especially on some of the cultivated forms throughout
the Americas and in Africa.

E. fuscum Schr.!

Sori in. leaves, about 2-6 mm. or by confluence much larger,
spores light yellow to chestnut-brown, provided (especially when
young) with a conspicuously swollen gelatinous envelope, smooth,
chiefly 13-19 » in length; the hypophyllous matted outgrowths
usually show few conidia which are fusiform, single-celled or sep-
tate, 10-22 x 3 un.

It occurs on Papaver in Europe and Eastern North America.

E. nymphez (Cunn.) Set.15”

Sori in leaves, forming variable and irregular areas, usually
most prominent on the under side, yellowish or with age reddish-
brown, scattered or confluent; spores hyaline, ovoid to subspherical,
usually apiculate and with the remains of the hypha as a basal
appendix, smooth or under an immersion lens minutely verrucu-
lose, 10-14 uw in length; conidia not observed but spores said to
germinate in situ.

On leaves of various water lilies in both the old and new world.

Doassansia Cornu.!*” 1 (p. 315) -

Sori in various parts of the host, usually
in the leaves, rather permanently embedded
in the tissues; spore-balls conspicuous, per-
manent, consisting of a distinct cortical
‘layer and a central mass of fertile cells en-
Fic. 238. — Doassansia, tirely filling the interior, or with the inner-

ta sa ees most cells supplanted by parenchymatous

sterile and fertile cells. cells or hyphal threads; spores hyaline or
miter Uteiel. yellowish, with smooth, usually thin, walls;
germination often in situ, by means of a short promycelium whicb

THE FUNGI WHICH CAUSE PLANT DISEASE 323

gives rise to a terminal group of elongate sporidia, these often
bearing secondary and even tertiary groups.

The only species of this genus which occur on economic plants
are D. gossypii Lagerh.*? on cotton in Ecuador and D. niesslii
de Toni (Niess) Schr. on Butomus.

The following genera, which are usually referred doubtfully to
the Ustilaginales will be found under “Genera of Unknown Af-
finity” page 663.

Graphiola Poit. on various palms. Schinzia Nag. on Solanum.
Bornetina M. & V. on Vitis.

Protobasidii (p. 299)

The three orders which belong to this group are characterized
by septate basidia.

Key To Orpers or Protobasidii

Basidia with cross walls
Basidia arising from chlamydospores,
Life cycle polymorphic. Parasites..... 1. Uredinales, p. 323.
Basidia not arising from chlamydospores
- Not polymorphic. Gelatinous sapro-

PhYyles 3 ek sean enna eres 2. Auriculariales, p. 392.
Basidia with lengthwise partitions, gelat-
inous saprophytes. ................. 3. Tremellales.

° 45, 49, 56, 60, 61, 166, 170-175, 178, 183-187
Uredinales ie eae *

Small fungi, mostly microscopic, parasitic in the tissues of
ferns and seed plants. Mycelium much branched, septate, and
with haustoria. Spores borne in sori below the surface of the host,
or rarely single within the host. Sori naked, enclosed by peridia
or paraphyses, or embedded in a thin stroma. Spores of five mor-
phological sorts, not all present in every genus; (1) basidiospores,
minute, thin-walled, without surface sculpturing, (2) pycniospores,
small, smooth, of unknown function, (3) zciospores, verrucosely
sculptured, borne in chains, (4) urediniospores, echinulately or

* Arthur’s terminology involving the words pycnium, «cium, uredinium,
telium and derivatives from these words, will be followed in the treatment of

this order.

324 THE FUNGI WHICH CAUSE PLANT DISEASE

verrucosely sculptured, borne singly, or sometimes in chains,
(5) teliospores, smooth or variously sculptured but not echinulate,
borne singly or in chains. In every species the mycelium even-
tually gives rise to teliospores, which produce in germination
four basidia, either remaining within the spore-cell or borne in
the air on a short promycelium, each basidium supporting a single,
stalked or sessile basidiospore.

The order of some two thousand species, constituting the
“rust” fungi, many of them living on cultivated plants of high
value, is of great economic significance. Its members are strict,
obligate, parasites which in no stage of the life except in the
promycelial stage can develop other than on the living host.
The complexities of the life histories of the species, with their five
distinct spore forms, inhabiting at different seasonal periods two
or even three different host
plants, renders the order both
difficult and exceedingly in-
teresting.

The life history of the most
complete of these fungi may
be stated as follows:

I. Aicia (ecidia) and O.
pycnia (often called spermo-
gonia or pycnidia). The my-
celium arising from a basidio-
spore invades the host plant,
and vegetates until vigor suf-
ficient to spore formation is
attained, meantime often pro-
ducing local spotting, hyper-
trophy, or other injury to the

Fic. 239.—Aicium and pycnium. After host. The mycelium then de-

Tavel. : u

velops a stroma which pro-

duces spore beds (sori) and ruptures the epidermis. These sori
are usually deeply sunken in the host and cup-shaped and take
the common name “cluster cups,” Fig. 239, technically cia or
zcidia. The sporophores arise from a hyphal plexus at the base
of the cup and the spores are borne catenulate in acropetal suc-

THE FUNGI WHICH CAUSE PLANT DISEASE 325

cession. The whole structure is usually red or yellow. The outer
layer of the cup usually consists of a palisade of sterile sporo-
phores bearing sterile cells and constitutes the peridium. The
zeciospores are usually nearly globular, or angular by compression,
reddish and rough and sometimes bear germ pores. They are ca-
pable of germination at once and on germination give rise to germ
tubes which may infect susceptible hosts, leading to a mycelium.
This in turn again produces sori which in some species may be
zecia, in others telia, but in most species, uredinia.

Associated with the xcia, occasionally with other spore forms,
but never borne alone, are minute pycnia with sporophores
arising from their walls and bases. These bear unicellular pycnio-
spores. Sterile hairs usually protrude from the ostioles. The
whole structure in gross appearance is much like the pycnidium
of Phoma or Phyllosticta but it is reddish or orange in color.
These pycnia were formerly often spoken of as “spermogonia”’
and the spores as ‘‘spermatia,” due to the thought that they stood
for degenerated male organs; a view supported by the fact that
the spores were not observed to germinate. Germination ?* has
now been observed and there is no longer reason to regard them
as sexual organs.

II. Uredinia (uredo-sori). The sciospores may infect the
same species of plant that produced the eciospores (aute-
cious) or plants of an entirely different species (hetercecious).
The mycelium produced by the eciospore develops within the
host; usually remains local, and causes spotting. When it has
attained sufficient vigor and age, usually after about two weeks,
it produces a sub-epidermal hyphal plexus from which arises a bed
of sporophores which bear unicellular, hyaline to brown, nearly
globose, thin-walled, usually echinulate or rough spores, each with
from 2 to 10 germ-pores variously placed. These are the ure-
diniospores borne in uredinia (uredo-sori). They may germinate
at once producing a germ tube which develops to a mycelium.

These spores falling on susceptible tissues, by infection, usually
stomatal, continue the production of uredinia and spread the
disease. The urediniospores are usually short-lived and function
to spread summer infection. They continue to form throughout
the growing season.

326 THE FUNGI WHICH CAUSE PLANT DISEASE

In a few species ” 8 there are what are known as amphispores
or resting forms of urediniospores provided with thickened walls.
They have colorless contents and pedicels more persistent than
those of the usual urediniospore.

III. Telia (teleuto-sori). Toward the latter part of the grow-
ing seasons another kind of spore appears, often in the same
sorus with the urediniospore and from
the same mycelium. It is of various
forms in different genera, one or more-
celled, varies in shape, thickness of
wall, surface marking, color, etc., but
is uniform in the character of the
germination which is very different from
that of any of the other rust-spores.

In teliospore germination, typically
each cell of the teliospore sends forth
one germ tube. These tubes soon cease
growth and by septation become 4-celled.
Each cell then sends out a short branch
(sterigma) on which there develops one
round or oval, 1-celled, thin-walled spore,
the basidiospore, often in this group
called the sporidium.

Morphologically the promycelium is a
basidium bearing its four sterigmata and
Fic. 240.—Germination of four basidiospores. Relationship is thus

teliospores of P. asparagi. shown on the one hand to the Ustilagi-

nales, on the other hand to the Auricula-
riales, an assumption that is borne out by cytological evidence.
Deviations from the typical mode of germination are found in sev-
eral genera mentioned below (e. g., Coleosporium).

Basidiospores germinate immediately by germ tubes which on
suitable hosts give rise again to «cia and pycnia or in some
species to other spore forms completing the life cycle.

The most complex life cycle is thus seen to comprise pyenio-
spores, seciospores, urediniospores, teliospores and basidiospores.
For brevity the first four stages are commonly designated by
the following symbols:

THE FUNGI WHICH CAUSE PLANT DISEASE 327

O. Pyenia or pyenial stage

I. Acia or ecial stage

II. Uredinia or uredinia stage
III. Telia or telial stage

The spores in all cases, except those of the basidiospores and

Fic. 241.—Amphispores, urediniospores and teliospores of Puccinia vexans,
After Holway.

pycniospores arise by direct conversion of a mycelial cell into
a spore, i. e., they are chlamydospores.

Mesospore is a term applied to occasional unicellular forms of
teliospores found in Puccinia and related genera which do not
usually have unicellular teliospores.

As has been said the pyeniospores seem to be functionless
though by some it is thought that they do function but that man
has yet failed to find the conditions under which they readily
germinate and cause infection. The ecial stage appearing first,
and thus commonly in the spring, is often called the “spring stage.”

328 THE FUNGI WHICH CAUSE PLANT DISEASE

It serves as an early stage to propagate and spread the fungus.
The uredinia often called the ‘‘summer stage” constitute the
phase usually of longest duration and of most injury. Its function
is preéminently to multiply and spread the fungus.

The telia, often called the “winter stage,” usually, but not al-
ways, constitute the resting, hibernating stage. In many instances
the teliospores must rest over winter before they are capable of
germination. Classification is based primarily on the teliospores.

While all five of the spore forms discussed above are typical of
many species there are many other species which do not possess
all of these forms or indeed which may possess only one spore form.

Schréter” for convenience groups the rusts, according to the
spore forms that they show, under the following type names
though it must be recognized that such grouping is purely arti-
ficial and does not necessarily bring together closely related species.

Eu-type O, I, II, III present;

Brachy-type O, II, III present; I omitted.
Opsis-type 0, I, III present; II omitted.
Hemi-type II, III present; O, I omitted.
Micro-type only III present; germination only after
a resting period.
Lepto-type only III present; germination without a

resting period.

As examples of the above we have the following:

Eu-type, Puccinia asparagi, O, I, I, and III, all on Aspar-
agus.

Brachy-type, Puccinia‘suaveolens, O, II, and III, all on thistle.

Opsis-type, Puccinia tragopogonis, O,I, and III, all on salsify.

Hemi-type, Uromyces caryophyl-

linus, II, and III, both on Di-
anthus.
Micro-type, Puccinia ribis, ITI, on Ribes.
Lepto-type, Puccinia malvacea-
rum, III, on hollyhock.

Hundreds of the hemi-types will doubtless be revealed by study
to be hetercecious eu-types.

THE FUNGI WHICH, CAUSE PLANT DISEASE 329

Heterecism.*” All of the examples just given are auteecious,
i. e., all known spore forms are found on the same species of host
plant. In many other rusts, however, hetercecism prevails, i. e.,
one stage of the fungus is found on one species of host and another
‘stage upon another host; rarely three host plants are involved in
the cycle. Aside from the rusts only one other fungus (Sclerotinia
ledi) is known to show hetercecism.

Hetercecism has been experimentally proved in some one hun-
dred and fifty cases and may be assumed to exist in many hun-
dreds of cases not yet investigated.

Examples of hetercecism are as follows:

Stages O, I. Stages II, III.
Eu-type, Puccinia graminis, _Berberis Wheat
“« rubigo-vera, Boraginaceze -
“ sorghi, Oxalis Corn
Uromyces pisi, Euphorbia Pea
Opsis-type, Gymnosporangium
macropus, Apple Red cedar (III)

It frequently
happens that part
of the life cycle is
passed upon a mo-
nocotyledonous
plant, the remain-
der upon a dicoty-
ledon. In such
event it is more
often the II and
III stages that are
on the monocoty-
ledon while the O,
I stages are on the
dicotyledon; exam-

ples of this are af-

] _ Fic. 242.—Urediniospore of P. asparagi germinating on
forded in the nu surface of plant, and separate spores. After Smith.

merous rusts of i
grasses, sedges and rushes. In one group the pycnia and the

330 THE FUNGI WHICH CAUSE PLANT DISEASE

eecia are on pines (Peridermium), while the other stages are
on dicotyledons. In the Gymnosporangiums the pycnial and
ecial stages are on Rosacezx; the telial on Juniperus and its kin.
While a few general rules can be worked out concerning host
relations there are many exceptions and to know one stage of
a hetercecious rust generally gives little or no clue to what its
complementary host may be.

The mycelium of the rusts is usually intercellular and local though
in afewinstances it is extensive and even perennial in thehost. Itis
abundantly branched, closely septate, gives off haustoria and usually
bears numerous oil drops which lend a yellow or orange color.

Irritation by the mycelium often induces marked hypertrophy
or even witches’ brooms or other deformation of the host. Hy-
pertrophy is most common with the ecia but may result
from the telia as
well, as is conspicu-
ously shown in the
genus Gymnospor-
angium. In some
instances the whole
habit of the host
plant is altered by
the presence of the
mycelium so as to

fog "¢ render it almost un-
og recognizable, e. g.,

the xcium of Uro-
Fic. 243.—Cross-section, showing infection from spore oak
of P. asparagi. After Smith. myces plsi on Eu-

phorbia.

The host cells are seldom killed by the mycelium, which ab-
stracts its food supply from the carbohydrates and other nutrients
of the cell sap without direct injury to the protoplasm, though
ultimately there is serious effect upon both growth of the host
and its seed production.

Cytology.” 18 18% 313-315 Dangeard *!4 and Sappin-Trouffy 313
showed that the mycelial cells of the rusts are binucleate, a condi-
tion which begins just below the xcium. The origin and signifi-
cance of this condition is of much interest.

THE FUNGI WHICH CAUSE PLANT DISEASE 331

In all of the rusts so far investigated that have an ecium or
primary uredinium there is in the zecio-mycelium or the primary
uredinio-mycelium a fusion of uninucleated cells, gametes. This
cellular fusion is not, however, followed by a nuclear fusion until
after long delay; but the two nuclei remain in the fusion cell and
when this cell divides both nuclei divide mitotically and simul-
taneously but still independently of each other (conjugate division).
This process continues through the ecial sporophores, or uredinial
sporophores, and in the production of the spores, with the result

Fic. 246. — Conjugate

Fic. 244—Showing Fic. 245.—Gymnospo- nuclear division in
conjugate nuclei and rangium, _ clavarise- Gymnosporangium
degenerating cells in forme, mitosis of a clavarieforme show-
conidiospore chain nucleus in the promy- ing four chromatin
of Acidium. After celium. After Black- masses. After
Sappin-Trouffy. man. Blackman.

that the cells of all of these are binucleate. The conjugate divi-
sion continues further through the uredinia and until teliospore
formation occurs, the whole intervening series of cells being binu-
cleate. Prior to the formation of the promycelium and in the
teliospore the nuclei unite, reducing the cells again to an uninu-
cleate condition.

In rusts which have only teliospores the binucleate condition
begins somewhere in the mycelium from which the teliospores
arise.

It is generally held that the cellular fusion is a sexual act
with long delayed fusion of the sexual nuclei: and consequently
that the uninucleate phase is the gametophyte; that the be-

332 THE FUNGI WHICH CAUSE PLANT DISEASE

ginning of the binucleate condition marks the origin of the sporo-
phyte.

Biologic specialization 1%! 177174 309 much as is found in the Erys-
iphales occurs also in the Uredinales. There are many species, each
of which is found on a large number of hosts. Upon its numerous
hosts the fungus may show no morphological variation, yet at-

Fic. 248.— Diagram-
matic representation

Fic. 247.—Conjugate nu- of fusion of nuclei
clear division in cells of in the teliospore. Af-
Puccinia podophylli. ter Delacroix and
After Christman. Maublanc.

tempts to inoculate from one host to another may uniformly give
negative results. It further often occurs that one stage, e. g.,
the ecia of a species may grow upon only one host while the
uredinia or telia may grow upon many different species of hosts;
and in such cases that eciospores which have arisen on host X,
from infection with spores from host A, are capable of infecting
host A and that host only; while eciospores which have arisen
on host X, by infection with spores from host B, are capable of
infecting host B and only this host; and so on for numerous forms.
Yet the uredinia and telia of these different races may be mor-

THE FUNGI WHICH CAUSE PLANT DISEASE 333

phologically inseparable as are also their ecia when grown upon
their common host.

An excellent example of such biologic specialization is offered
in the common pine Peridermium. Aicia may be produced upon
the pine by sowing of Coleosporium teliospores from Senecio,
Campanula, Pulsatilla, etc., but the sxciospores which develop
on the pine are capable of in-
fecting only those species of
hosts from which the telio-
spores were taken.

Similarly Eriksson !74 has de-
termined that though rusts
from many grains can infect
the barberry, the sciospores
there produced are not capable
of infecting plants of species
other than those from which
the fungus was derived, or at
most they can infect but a
very limited number of species.

A further complication arises oe ‘
from the facts obtained through sees ae ae wey pipes
experiments in various coun- ™@"
tries, which have shown that what is apparently the same species
may consist of a large number of strains or varieties which be-
have differently in different geographic areas. The stem rusts of
wheat and barley, for instance, are very similar, interchanging
hosts easily and being capable of transfer to various grasses in this
country, though in Sweden the stem rust of wheat goes with
difficulty to barley and rye, while the stem rusts of barley and
rye interchange hosts very easily.

Owing to the prominence of its author and its place in litera-
ture a word may be given to the usually discredited mycoplasm
theory 1°19 312 of Eriksson. This affirms the existence in the
cells of wheat grain of an intimate mixture of rust protoplasm and
host protoplasm. This mycoplasm may rest thus for months.
Finally the host-cell nucleus becomes digested and the fungous
plasm develops to a mycelium which proceeds to invade the sur-

334 THE FUNGI WHICH CAUSE PLANT DISEASE

rounding tissues of the seedling as these develop on germination
of the seed.

Infection Experiments. Since the method of studying the
rusts by observing their life histories in the laboratory where
they are under complete control of the observer has assumed
such prominence of late years the technique deserves notice.
The first step is to find associated in the field the xcia and
other stages of a rust in such way as to suggest relation-
ship between two forms hitherto unknown to be connected.

Material of the rust is then collected and healthy host plants
are also removed to the laboratory. If the teliospores are col-
lected in the fall they are kept out of doors in cheese cloth bags
till germination time in the spring. Whether collected in spring
or fall the viability of the spores must be tested by sowing in a
hanging drop of water. If germination is plentiful then the infec-
tion experiment is made. First the suspected alternate host is
sprayed with water to give the spores proper conditions for ger-
mination, then masses of spores are placed directly on the plant
by a scalpel and a bell jar is placed over the plant to assure a humid
atmosphere. In from five to eight days yellow spots should indi-
cate where the infection has taken place and in a short time
pyenia and excia or other sori follow. In all infection work it is
imperative to know that the plants used be not already infected
in the field from another source.

The ecium is by some regarded as a structure whose function
is to restore vigor to the rust fungus.*® On the other hand,
Freeman and Johnson ® found that in fifty-two generations
of the fungus, without the intervention of excia or telia there
was no apparent diminution in the vitality of the uredinial
generation.

Form Genera. The telial stage is regarded as the highest
stage of the rust fungus and is the one on which classification is
often based. Thus an xcium, uredinium, cxoma, etc., that is
known to possess a telial form is regarded as part of the species
indicated by its teliospore, e. g., Aucidium berberidis being part
of Puccinia graminis has no specific identity but is regarded as
a stage of P. graminis.

There are numerous uredinia, ecia and other non-telial forms

THE FUNGI WHICH CAUSE PLANT DISEASE 335

of which the telial stage is not yet known. It becomes neces-
sary for the present, for convenience of reference, to have
names by which to designate these forms. For this purpose the
form-genera Aicidium Czoma, Peridermium, Reestelia and Uredo
are recognized. We group these under the heading Uredinales
Imperfecti.

Darluca and Tuberculina, two imperfect fungi, are often found
growing as parasites upon the rust fungi.

Key To Famiuies or Uredinales

Teliospores in germination becoming
4celled, compacted _ laterally
into waxy layers; walls of the
spores weakly gelatinous...... 1. Coleosporiacee, p. 335.
Teliospores germinating by a promy-
celium
Teliospores compacted laterally
into a crust or column (rarely
solitary within the tissues);
walls of the spores firm..... 2. Melampsoracer, p. 340.
Teliospores free or fascicled; walls
of the spores firm or with an
outer hygroscopic layer cov-

ered by cuticle............. 3. Pucciniaceer, p. 353.
Teliospores unknown.............. 4, Uredinales Imperfecti, p. 389.
Coleosporiaceze

Teliospores united in a one or two-layered waxy cushion, ses-
sile or borne on a broad sac-like stalk and then at the beginning
2-celled. Each original spore-cell divides to four super-imposed
cells from each of which a simple sterigma emerges. This bears a
large basidiospore.

The most important character is the peculiar mode of basidio-
spore production, the 4-celled promycelium being formed within
the spore.

The family is of little economic importance except in its ecial
stage on conifers.

336 THE FUNGI WHICH CAUSE PLANT DISEASE

Key to GENERA oF Coleosporiacez.

Basidiospore spindle-shaped. ............. 1. Ochropsora, p. 336.
Basidiospore ellipsoid
Teliospores in a single layer
Teliospore layer strongly arched, form-

ing minute knobs............... 2. Mikronegeria.
Teliospore in a flat crust............. 3. Coleosporium, p. 336.
Teliospores in a double layer, long-
stalked esse tisketey Canova dass 4. Chrysopsora.
Teliospores in a columnar mass........ 5. Trichopsora.

Ochropsora Dietel

II. Urediniospores solitary.

III. Teliospores in a waxy crust, loosely united, originally
1-celled, later 4-celled, each cell bearing a single basidiospore on
a simple sterigma.

O. sorbi (Oud.) Diet.

I. Aciospores (=e. leucospermum) on anemone.

II and- III. Urediniospores on Sorbus and Spirea.

Coleosporium Léviellé

O. Pyenia flattish, linear, dehiscent by a slit, without ostiolar
filaments.

I (=Peridermium). cia erumpent, definite. Peridium color-
less with verrucose walls. Spores globose to oblong, with colorless
walls, the outer part formed of densely packed, deciduous tubercles.

II. Uredinia erumpent, definite, without peridium. Spores
catenulate, globoid to oblong, pulverulent; wall colorless, closely
verrucose, pores obscure.

III. Telia indehiscent except through weathering, waxy, some-
what indefinite, usually roundish. Spores sessile, 1-celled (by
early division of the contents appearing 4-celled); wall smooth,
colorless, thickened and gelatinous at apex.

The genus is usually hetercecious. Arthur ® lists some twenty-
four species for America.

There are many biologic forms, morphologically indistinguish-

THE FUNGI WHICH CAUSE PLANT DISEASE 337

able yet not inter-inoculable. The excial stage is found on
leaves of conifers, the telia on a large variety of hosts.

C. ipomcee (Schw.) Burr.

O and I. Unknown.

II. Uredinia hypophyllous, widely scattered or somewhat
clustered, 0.25-1 mm. across, early naked, orange-yellow fading to
white, ruptured epidermis usually inconspicuous; spores ellipsoid,
13-21 x 18-27 u, more or less angular and irregular; wall thin,
1-1.5 y, closely and noticeably verrucose.

III. Telia hypophyllous, widely scattered, often confluent, pul-
vinate, 0.5 mm. or less across, deep reddish-orange fading to pale-
yellow; spores with wall swelling 20-40 » above; contents orange-
yellow fading to colorless, oblong, or slightly clavate, 19-23 x
60-80 yu, rounded or obtuse at both ends.

Common on various Ipomceas and their kin among them morn-
ing glory and sweet potato.14

C. solidaginis (Schw.) Thtim.*® 19°19"

O. Pycnia amphigenous, scattered, numerous, originating be-
tween mesophyll and cortical layer, noticeable, 0.3-0.5 mm. wide
by 0.5-0.8 mm. long, dehiscent by a longitudinal slit, low-conoidal,
80-100 pu high.

I (=Peridermium acicolum). cia from a limited mycelium,
amphigenous, numerous, scattered on discolored spots occupying
part of a leaf, erumpent from longi-
tudinal slits, tongue-shaped, 0.5-1 mm.
long by 0.5-0.7 mm. high; peridium
rupturing irregularly, moderately firm,
white, cells overlapping, 35-45 wu long,
not much narrower, walls transversely
striate, inner coarsely verrucose, thick,
5-6 », outer less rough and somewhat

; is : Fic. 250.—Stages O. and I. of
thinner; spores ellipsoid, 20-25 x Coleosporium solidapinis

(Peridermium) on Pinus

28-40 yw; wall colorless, closely and Sad Cee Chae:

coarsely verrucose with deciduous tu-
bercles which are directed away from a smooth spot extending
up one side, thick, 2-3 » on the smooth spot, increasing to
5-6 » on the opposite side, including the tubercles.

II. Uredinia hypophyllous, rarely also epipbyllous, irregularly

338 THE FUNGI WHICH CAUSE PLANT DISEASE

scattered, or at first somewhat gregarious and crowded, 0.3-0.5 mm.
- across, soon naked, yellow or orange-yellow, ruptured epidermis
inconspicuous; spores ellipsoid or globoid, 17-22 by 20-30 uy;
wall rather thin, 1-2 yw, closely and strongly verrucose; contents
orange-yellow when fresh, fading to colorless.

III. Telia hypophyllous, scattered irregularly or sometimes
crowded and confluent, slightly elevated, 0.3-0.5 mm. across,
reddish-orange; spores with wall swelling 30-40 yu thick above;
contents orange-yellow fading to colorless, terete, 15-23 x 55-
80 u, rounded or obtuse at both ends; basidiospores globoid or
elliptical, about 12 x 18 u, orange-yellow.

I. Acia on Pinus rigida.

II and III. Uredinia and telia on Aster, Solidago and culti-
vated aster (Callistephenis); widespread and common. The con-
nection between the stages was demonstrated by inoculations by
Clinton.” 197

C. senecionis (Schum.) Fries.

O. Pycnia amphigenous, scattered, numerous, originating be-
tween mesophyll and cortical layer, noticeable, 0.2-0.3 mm. wide,
0.5-1 mm. long, dehiscent by a longitudinal
slit, 70-100 » high.

I (=Peridermium oblongisporium). cia
from a limited mycelium, amphigenous, bul-
late, tongue-shaped, 1-2 mm. long, 0.7-
1 mm. high, whitish; peridium rupturing ir-
regularly, fragile, white, cells overlapping, outer
and inner walls of same thickness, 3-4 yu, outer
smooth, inner moderately verrucose; spores
Fie. 251. — Coleoapa- broadly ellipsoid, 17-24 by 28-36 uy, wall

Hun Be fash colorless, thick, 3-4 yu, densely verrucose with

fon of eee prominent elongate papille.

II. Uredinia hypophyllous, thickly scattered,
about 0.5 mm. across; early naked, bright orange-yellow fading
to pale-yellow, ruptured epidermis evident; spores elliptical-
globoid or obovate-globoid, 17-21 by 20-27 y; wall thin, 1-
1.5 w, evenly but not densely verrucose, with low papille.

III. Telia hypophyllous, scattered, often confluent, small, 0.3
mm. across, brilliant orange-yellow fading to pale orange-yellow;

THE FUNGI WHICH CAUSE PLANT DISEASE 339

spores with wall swelling 15-25 y» thick above; contents orange-
yellow fading to pale-yellow, clavate or clavate-oblong, 16-20 by
60-83 u, rounded at both ends or narrowed below.

I. Aicia on Pinus sylvestris.

II and III. Uredinia and telia on Senecio. What may be this
same fungus is reported also on cultivated Cineraria.% The
teliospores hibernate in their dark-red sori producing promycelia
in the spring. The sporidia bring about spring infection of the
pine leaves and young twigs, later resulting in pycnia and ecia.
The connection of the forms was established by Wolff in 1872.

C. pini Gall.“ *%°

O. Pyenia unknown, probably wanting.

III. Telia amphigenous, on yellow spots, usually near the tips
of the leaves, long covered by the epidermis, 1-5 mm. long, or
when confluent up to 10 mm. or more, reddish-orange fading to
pale-yellow or dirty-white, ruptured epidermis inconspicuous;
teliospores with walls swelling 30-50 u above, and soon dis-
appearing upon exposure; contents orange-yellow fading to nearly
colorless, clavate, slender, 13-20 by 60-100 u, acute or rounded
above, much narrowed below, sides wavy or irregular.

This is set apart by Arthur “* as the type of a distinct genus,
Gallowaya, based on the absence of spore forms other than the
teliospores.

It causes serious leaf loss on Pinus virginiana.

C. campanule (Pers.) Lév.

OQ. Pycnia amphigenous, scattered, numerous, originating be-
tween mesophyll and cortical layer, noticeable, large, 0.2-0.4 mm.
wide, 1~2 mm. long, dehiscent by a longitudinal slit, 90-110 »
high.

I (=Peridermium rostrupi). A®cia from a limited mycelium,
amphigenous, scattered, 1-3 on discolored spots, bullate, tongue-
shaped, large, 1-3 mm. long, 0.7-1.5 mm. high, yellow, fading to
white; peridium rupturing irregularly, fragile, white, cells overlap-
ping, outer and inner walls same thickness, about 4-6 yu, outer
smooth, inner moderately verrucose; spores broadly ellipsoid or
globoid, 17~22 by 22-31 yu; wall colorless, thin, 2-3.5 u, densely
verrucose, with prominent, elongate papille.

II. Uredinia hypophyllous, scattered, often confluent, 0.5-1 mm.

340 THE FUNGI WHICH CAUSE PLANT DISEASE

across, soon naked, orange-red fading to white, ruptured epidermis
evident; spores ellipsoid, 18-23 by 20-30 yu; wall thin, 1-1.5 up,
densely verrucose, with prominent, elongate papille.

III. Telia hypophyllous, scattered, often confluent, small, 0.2—
0.5 mm. across, slightly elevated, blood-red, fading to pale brownish-
yellow; spores with wall swelling 15-25 u thick above; contents
orange-red fading to nearly colorless, cylindrical or clavate-oblong,
17-24 by 55-85 yu, rounded or obtuse at each end.

O and I on Pinus rigida.

II and III on Campanula and kin.

There are numerous other species of less importance.

Melampsoracee (p. 335)

Telia forming a more or less definite crust or column; teliospores
compacted laterally into layers or rarely solitary in the tissues,
sessile; wall firm or rarely with a gelatinous layer. :

The family is of little importance. Its uredinial and telial stages
do slight injury on poplars and willows.

Key ro GENERA or Melampsoracee.

Telia indehiscent.
Sori all subcuticular; teliospores com-
pacted in dense layers to form a crust;
zcia when present without a perid-
ium; uredinia when present without
a peridium or with an imperfect
one of paraphyses
Teliospores in a single layer; uredinia
with spores and paraphyses inter-
MIXC0s coycsher Suen skies cues 1. Melampsora, p. 342.
Teliospores in more than one layer
Uredinia with peripheral paraphyses
ODN Ye soo duc eave ea aienaes 2. Physopella, p. 345.
Uredinia without paraphyses. ...... 3. Bubakia.
Pyenia subcuticular, other sori subepi-
dermal, or the telia within the epider-
mal cells or between the mesophyll
cells; uredinia when present with a
peridium

THE FUNGI WHICH CAUSE PLANT DISEASE 341

Teliospores approximating in a single
layer within or beneath the epider-
mis; urediniospores globoid to
oblong :

Walls of the teliospores colored
Urediniospores echinulate through-

Urediniospores echinulate except at
the apex: eset ceawesiscsic te
Walls of the teliospores colorless
Urediniospores echinulate. .......
Urediniospores verrucose........
Teliospores solitary within the meso-
phyll; urediniospores pointed . ...
Telia erumpent, sori all subepidermal
Teliospores compacted laterally; ecia
when present with flattened perid-
ium, rupturing apically; uredinia
when present with a delicate perid-
ium and catenulate spores
With all spore forms in life cycle......
With telia and pycnia only
Promycelium of the ordinary type.
Promycelial cells changing directly

4. Pucciniastrum, p. 346.
5. Melampsoridium, p. 347.

6. Melampsorella, p. 348.
7. Hyalopsora.

8. Uredinopsis.

9. Melampsoropsis, p. 349.

10. Chrysomyxa, p. 350.

to basidiospores. ............. 11. Barclayella.

Teliospores often adhering and extruded
in long columns; zcia when present
with inflated peridium, dehiscence
circumscissile; uredinia when present,
with peridium, spores borne singly on
pedicels.

Teliospores 1-celled
Telia naked
Telia forming columns
Teliospores firmly united side-
wise and endwise...........
Teliospores loosely united later-

12. Cronartium, p. 350.

ally, separating in disks.... 13. Alveolaria.

Telia not extruded
Wall brownish, thick .........
Wall colorless, thin.. .........

14. Beodromus.
15. Cerotelium.

342 THE FUNGI WHICH CAUSE PLANT DISEASE

Wall slightly colored. ......... 16. Cionothrix.
Telia with a peridium
Telia half projecting above the

host surface. ............... 17. Dietelia.
Telia sunken in the tissue of the
hOshinivisss ce een ee raceeiakts 18. Endophylium, p. 353.
Teliospores 2-celled
Peridium present. ................ 19. Pucciniosita.
Peridium none... ................. 20. Didymopsora.

Melampsora Castaigne (p. 340)

O. Pycnia half spherical.

I. Atcia of ceoma-type, no peridium or paraphyses.

II. Urediniospores solitary, membrane colorless.

a III. Teliospores 1-celled, rarely

KSEE more, in flat irregularly limited
yoeZz=>6 crusts. Basidiospores spherical.

The question of biologic speciali-
zation is especially complicated in
this genus. The uredinial and telial
stages occur in abundance on wil-
lows and poplars, the ecial stage on
a wide range of plants embracing
gymnosperms, monocotyledons and
dicotyledons.

M. lini D. C.

O. Pycnia amphigenous, numer-
ous, scattered, inconspicuous, sub-
epidermal, pale-yellow, flattened
globoid or lens-shaped, 100-175 yu

arate in diameter, 65-95 » high; spores
*ianum, chowing eerminating ellipsoid, 2-3 by 3-4 p.

telloapores: “titer Hareiy I. Atcia chiefly hypophyllous, nu-
merous, scattered, rounded, 0.2-0.4 mm. across, bright orange-
yellow, conspicuous, formed between epidermis and mesophyll,
soon naked, ruptured epidermis evident; spores globoid, 19-27 x
21-28 yu.; wall colorless, thin, about 1 u, finely and evenly verru-
cose, with distinct papille, pores not evident.

THE FUNGI WHICH CAUSE PLANT DISEASE 343

II. Uredinia amphigenous and caulicolous, scattered or some-
what gregarious, often crowded, round or on stems elongate,
0.3-0.5 mm. across, soon naked, reddish-yellow fading to nearly
white, pulverulent, ruptured epidermis noticeable; spores broadly
elliptical or obovate, 18-18 x 15-25 y, wall colorless, rather thin,
2 mu, evenly and finely verrucose, with low papille, pores equa-
torial, obscure; paraphyses intermixed with the spores, capitate,
large, 5-22 x 40-65 yw, smooth, wall thick.

III. Telia amphigenous and caulicolous, scattered, often con-
fluent, round or elongate, 0.2-0.5 mm. across, slightly elevated,
reddish-brown becoming blackish; spores subepidermal, appressed
into a single layer, prismatic, 1-celled, 10-20 x 42-50 u; wall
brown, smooth, thin, about 1 u, not thickened above.

Auteecious on flax. Sometimes very injurious.”

M. meduse Thiim.

O. Pycnia chiefly epiphyllous; scattered or somewhat gregarious,
minute, punctiform, pale-yellow, inconspicuous, subcuticular,
hemispherical, 40-80 » in diameter, half as high.

I. Atcia chiefly hypophyllous, scattered or somewhat grega-
rious, small, 0.1-0.3 mm. broad, round or oblong, pale-yellow
fading to white, inconspicuous, formed between epidermis and
mesophyll, soon naked, pulverulent, ruptured epidermis notice-
able; eciospores globoid, 17-22 by 17-24 yu; wall colorless, thick,
2.5-3 uw, minutely verrucose, with minute crowded papille, pores
indistinct.

II. Uredinia amphigenous, or only hypophyllous, scattered,
roundish, small, 0.2-0.4 mm. across, early naked, somewhat pul-
verulent, orange-yellow, fading to pale brownish-yellow, ruptured
epidermis usually inconspicuous; urediniospores ellipsoid or
obovate-ellipsoid, 15-18 by 22-30 yu, usually flattened laterally;
wall colorless, 2.5-3 » or up to 10 » on the flattened sides, sparsely
and evenly verrucose, with fine papille, except on the flattened
sides which are smooth; paraphyses numerous, intermixed with
the spores, capitate, smooth, 40-65 yu long, head 14-25 y» broad,
wall thick, 3-6 y, peripheral paraphyses thinner-walled and more
clavate.

III. Telia amphigenous or only hypophyllous, scattered or
somewhat confluent, irregularly roundish, small, 0.2-0.4 mm.

344 THE FUNGI WHICH CAUSE PLANT DISEASE

across, slightly elevated, light reddish-brown, becoming deep
chocolate-brown, subepidermal; teliospores prismatic, 12-15 by
30-45 yu; wall smooth, cinnamon-brown, uniformly thin, 1 yz.

O and I on Larix, II and III on Populus. Common on all
species of Populus and often doing serious damage by its early
defoliation of the trees.

M. bigelowii Thim. with O and I on Larix and II and III on
Salix is quite similar to the preceding. It occurs on practically
all species of willow.

Other species not found in America are:

M. allii-fragilis Kleb.31!

I on Allium vineale and A. sativum.

II and III on Salix.

M. allii-salicis albg# Kleb.*!!

I on Allium.

II and III on Willow.

M. allii-populina Kleb.*!!

I on Allium.

II and III on Populus.

M. Klebahni Bub.

I on Corydalis.

II and ITI on Populus.

M. larici-pentandre Kleb.*"!

I on Larix.

II and III on Salix.

M. larici populina Kleb.*!4

I on Larix.

II and III on Populus.

M. pinitorqua Rost.?"!

I (=Caoma pinitorquum). The Coma-stage is quite de-
structive to pine seedlings. The teliospores grow on Populus
leaves.

M. repentis Plow.

I (=Ceoma orchidis); cn Orchis. II and IIIon Salix.

M. ribesii-viminalis Kleb.*"!

I on Ribes. II and III on Salix.

M. rostrupii Wagn.?"!

I on Mercurialis. II and III on Populus.

THE FUNGI WHICH CAUSE PLANT DISEASE 345

M. saxifragarum (D. C.) Schr.
I and III on Saxifrages.

Physopella Arthur (p. 340)

Cycle of development imperfectly known; only uredinia and
telia recognized, both subepidermal. Uredinia erumpent, definite,
roundish, pulverulent, encircled by more or less clavate paraphyses
which are often united at their bases, or wholly, into a pseudo-
peridium opening by a central pore. Urediniospores borne singly
on pedicels, obovate-globoid or ellipsoid; wall pale-yellow, echinu-
late or rarely verrucose, pores obscure. ‘Telia indehiscent, form-
ing lenticular masses, two or more cells thick at center. Telio-
spores 1-celled; walls smooth.

P. vitis (Thiim.) Arth.”

II. Uredinia hypophyllous, scattered thickly over wide areas,
round, minute, 0.1 mm. or less across, soon naked, arising between
epidermis and mesophyll, surrounded by numerous incurved pa-
raphyses, pulverulent, pale-yellow, fading to dirty white, ruptured
epidermis inconspicuous; urediniospores broadly ellipsoid or obo-
vate, 13-17 by 18-27 u; wall nearly colorless, thin, 1 », minutely
and rather closely echinulate, pores obscure; paraphyses hyphoid,
curved and irregular, 6-10 » thick, 30-60 » long, wall uniformly
thin, 1 y, yellowish.

III. Telia hypophyllous, scattered thickly over large areas,
roundish, minute; 0.1-0.2 mm. across, indehiscent, 3 to 4-cells
thick; teliospores ovoid, 12-15 by 20-30 yu, wall smooth, nearly
colorless, thin, 1 u or less.

On grape leaves in Southern United States and West Indies.
Also in South America and Japan.

P. fici (Cast.) Arth.

II. Uredinia hypophyllous, scattered thickly over large areas,
roundish, usually small, 0.1-0.3 mm. across, or rarely larger, bullate,
arising between epidermis and mesophyll, tardily dehiscent by cen-
tral rupture, encircled by delicate, evanescent paraphyses, pulveru-
lent, pale cinnamon-brown, ruptured epidermis overarching or
erect; spores obovate-globoid, 14-20 by 18-27 y; wall pale-yellow,
thin, 1-1.5 y, sharply and rather sparsely echinulate, pores ob-

346 THE FUNGI WHICH CAUSE PLANT DISEASE

scure; paraphyses hyphoid, very delicate, collapsing, 60-80 u
long, wall colorless, very thin, slightly thickened at apex, 1 u.

III. Telia, unknown.

II. On fig and osage orange.

Pucciniastrum Otth. (p. 341)

Hetercecious. The cycle of development includes pycnia, 2cia,
uredinia and telia, with distinct alternating phases.

O. Pycnia subcuticular, low-conoidal, without ostiolar filaments.

I. Acia erumpent, cylindrical. Peridium delicate, verrucose
on inner surface. Spores ellipsoid, verrucose except one side which
is thinner and smooth.

II. Uredinia barely protruding through the epidermis, dehis-
cent by a central pore. Peridium hemispherical, delicate, cells
longer at orifice. Spores borne singly on pedicels, obovate to
ellipsoid; wall colorless, echinulate, pores indistinct.

III. Telia indehiscent, forming more or less evident layers in
the epidermal cells or immediately beneath the epidermis. Spores
oblong or prismatic, 2 to 4-celled by vertical partitions in two
planes; wall smooth, colored.

Arthur“ lists nine American species but none are very impor-
tant.

P. hydrangee (B. & C.) Arth.

O and I. Unknown. :

II. Uredinia hypophyllous, scattered, round, small, 0.1-0.2 mm.
across, dark-yellow fading to pale-yellow, ruptured epidermis
inconspicuous, dehiscent by a central pore; peridium hemispher-
ical, delicate, cells small, cuboid, walls uniformly thin, 1-1.5 u,
ostiolar cells slightly or not elongate, 10-16 y, barely pointed,
walls thin, smooth; spores broadly elliptical or obovate, 12-18
x 16-24 yw; wall nearly colorless, thin, 1-1.5 yu, sparsely and
strongly echinulate.

III. Telia amphigenous, or chiefly epiphyllous, effused, or
confluent into small angular groups, 0.3-0.8 mm. across, not
raised, reddish-brown; spores forming a single layer within the
epidermal cells, or sometimes between the epidermis and mes-
ophyll, globoid, 22-28 x 24-28 yu, wall dark cinnamon-brown,
uniformly thin, 1.5-2 p.

THE FUNGI WHICH CAUSE PLANT DISEASE 347

It is found in the uredinial and telial stages on Hydrangea on
which it may be quite serious. 7°?

P. goeppertianum (J. Kiihn.) Kleb.

J. (=. columnare) on Abies leaves. III on Vaccinium.

The eacial stage is the destructive form. It has been found

Fic. 253.—Melampsoridium, section through germinating
telium. After Tulasne.

but a few times in America,”" 3° while the telial stage is common.
Fig. 252.

P. pustulatum (Pers.) Diet. (=P. abieti-chamenerii, P. epi-
lobii.)

Oand I on Abies. II and III on Epilobium.

P. padi (Kze. & Schm.) Diet.

I (=. strobilinum) on fir.

II and III on Prunus padus.

P. myrtilli (Schm.) Arth. is found in the uredinial and telial
stages on various Vacciniums.

Melampsoridium Klebahn (p. 341)

O. Pyenia flattened-conoidal, without ostiolar filaments.

I. Acia erumpent, subcylindrical. Peridium regularly dehis-
cent, cells rhomboidal. Spores ellipsoid to globoid; wall colorless,
thin, verrucose except one side which is thinner and smooth.

Il. Uredinia somewhat erumpent. Peridium firm, dehiscent
by central pore; peridial cells isodiametric, those of orifice pro-

348 THE FUNGI WHICH CAUSE PLANT DISEASE

longed into sharp points. Spores borne singly on pedicels, ellipsoid;
wall colorless, echinulate, pores indistinct.

III. Telia indehiscent, forming evident layers immediately
beneath the epidermis. Spores oblong or prismatic, 1-celled;
wall smooth, slightly colored.

M. betulz (Schiim.) Arth. occurs, O and I on larch, II and III on
Betula.

Melampsorella Schriter (p. 341)

O. Pyenia hemispherical, without ostiolar filaments.

I. Acia erumpent, definite, oblong, bullate. Peridium color-
less, with thin-walled cells. A®ciospores ellipsoid; wall colorless,
thin, verrucose, without smooth spot.

II. Uredinia barely protruding through the epidermis, dehiscent
by a central pore. Peridium hemispherical, delicate, cells slightly
or not enlarged at orifice. Urediniospores borne singly on pedicels,
obovate to ellipsoid; wall slightly colored, echinulate, pores ob-
scure.

III. Telia effused, indehiscent. Teliospores globoid to ellipsoid,
1-celled; wall smooth, colorless, thin.

M. elatina (A. & S.) Arth.4

O. Pycnia epiphyllous, few, scattered, punctiform, inconspicu-
ous, subcuticular, not extending much into walls of epidermis,
depressed-hemispherical, small, 100-130 » broad, 40-50 yu high.

I. Ascia from a perennial mycelium, dwarfing the young shoots,
and forming witches’ brooms, hypophyllous, forming two ir-
regular lines, deep-seated, wholly dropping out of the substratum
at maturity, roundish or irregularly oblong, large, 0.5-1 mm.
across, bladdery, soon open by falling away of the upper part;
peridium colorless, dehiscence irregular, cells with thin inner and
outer walls; zciospores broadly ellipsoid, or nearly globoid, 14~
18 x 16-28 yu; wall colorless, thin, 1-1.5 yu, closely and rather
finely verrucose.

II. Uredinia amphigenous, scattered or somewhat grouped,
small, round, 0.1-0.4 mm. across, orange-red when fresh, pale-
yellow when dry; peridium hemispherical, dehiscent by a small
central orifice, cells elongate at sides, polygonal above, inner and
outer walls same thickness; urediniospores ellipsoid or obovoid,

THE FUNGI WHICH CAUSE PLANT DISEASE 349

12-18 x 16-30 y; walls pale-yellow, rather thin, 1-1.5 4; sparsely
echinulate with short conical points. _

III. Telia hypophyllous, on whitish or pale reddish spots;
teliospores within the epidermal cells, 1-celled, short-cylindrical
or polygonal, 13-20 » broad; wall colorless, smooth, thin.

I (=Peridermium elatinum) on fir causing swelling, cankers and
witches’ brooms.

II and III on various members of the pink family.

All stages possess perennating mycelium. The ecial stage
is of most economic significance, producing witches’ brooms of
various sizes. The ecia are formed only on the deformed needles
of the witches’ brooms.

Melampsoropsis (Schréter) Arthur (p. 341)

Cycle of development includes pyenia, «cia, uredinia and telia,
with distinct alternating phases; hetercecious. Pycnia and other
sori subepidermal.

O. Pycnia deep-seated, somewhat erumpent, flask-shaped.

J. Acia erumpent, flattened laterally. Peridium firm, outer
wall of cells greatly thickened and transversely striate, inner wall
smooth. Aéciospores ellipsoid to globoid; wall colorless, coarsely
verrucose with deciduous tubercles.

II. Uredinia erumpent, pulverulent. Peridium very delicate,
evanescent, sometimes wanting. Urediniospores catenulate,
globoid to lanceolate; wall colorless, verrucose with somewhat
deciduous tubercles, pores obscure.

III. Telia erumpent, definite, roundish, waxy becoming vel-
vety. Teliospores catenulate, 1-celied, oblong or cuboid; wall
colorless, thin, smooth.

M. rhododendri (D. C.) Arth.

Uredinial and telial stages on Rhododendrons; pycnial and
ecial stages (=Xcidium abietinum) on Picea excelsa.

The pycnia appear on fir leaves in spring and about a month
later the xcia. The eciospores germinate upon the Rhododen-
dron. The mycelium perennates in its evergreen leaves and
produces the uredinial and telial stages, the former of which
serves for dissemination. The basidiospores infect the young fir
leaves.

350 THE FUNGI WHICH CAUSE PLANT DISEASE

Chrysomyxa Unger (p. 341)

III. Teliospores formed of a series of superimposed cells, of
which the lower are sterile,
forming flat or slightly ele-
vated, orange or reddish,
waxy, crusts. Germina-
tion of the teliospore by a
promycelium from each
cell, which produces mostly
four basidiospores.
. C. abietis (Wal.) Ung.

Fic. igs A ero aaa Ped cag section Telia only. It forms

yellow spots on spruce
leaves and the basidiospores seem able to infect the same host.
European.

Cronartium Fries (p. 341)

O. Pycnia deep-seated, broad and flat.

I (=Peridermium). A®cia erumpent, inflated. Peridium mem-
branous, rupturing at the sides rather than above, 2-4 cells thick,
outer surface smooth, inner verrucose. Spores ellipsoid; wall
colorless, coarsely verrucose with deciduous tubercles, except a
smooth spot on one side.

II. Uredinia somewhat erumpent. Peridium moderately firm,
rupturing above, upper part evanescent; peridial cells isodiametric.
Spores borne singly on pedicels, globoid to ellipsoid; wall nearly or
quite colorless, echinulate, pores obscure.

III. Telia erumpent, at first arising from the uredinia, the
catenulate spores adhering to form a much extended, cylindrical or
filiform column, horny when dry. Spores oblong to fusiform,
1-celled; wall slightly colored, thin, smooth.

Five American species are recognized by Arthur.*®

All known ecial stages are Peridermiums on stems of conifers.

C. ribicola F. de Wal.782-85 27

O. Pyenia caulicolous, scattered, honey-yellow, forming minute,
bladdery swellings. Spores hyaline, ovoid to elliptical, 1.9-4.7 p.

THE FUNGI WHICH CAUSE PLANT DISEASE 351

I (=Peridermium strobi). cia caulicolous, causing fusiform
swellings of the stem, rounded to elongate; peridium inflated, rup-
turing at sides, thick, membranous. Spores ellipsoid to ovoid,
18-20 x 22-23 y, wall colorless, coarsely verrucose except on
elongate smooth spot, 2-2.5 uw thick, on smooth spot 3-3.5 u
thick.

Il. Uredinia hypophyllous, thickly scattered in groups, round,
pustular, 0.1-0.3 mm., at first bright yellow; peridia delicate.

I

EO nance

B
Fig. 255.—Cronartium. A, uredinium; B, telium.

After Tubeuf.
Spores ellipsoid to obovate, 14-22 x 193.5 yw, wall colorless,
2-3 wu thick, sparsely and sharply echinulate.

III. Telial columns hypophyllous, cylindrical, 125-150 u thick,
up to 2 mm. long, curved, bright orange-yellow, becoming brown-
ish; spores oblong or cylindrical, 8-12 x 30-60 y; wall nearly
colorless, smooth, rather thick, 2-3 yu.

Hetercecious O, I, on white pine, Pinus cembra and several
other 5-leaved species; II and III on currant and gooseberry and
several other species of Ribes.

The telial stage was first noted in Geneva, N. Y., in 1906.74
The rust is now known in some nine states. It has been known in
Europe since 1854. Its effects are most serious in its ecial stage,
though the telial stage is very abundant and conspicuous. The
generic connections of the forms was proved by Klebahn in 1888
by inoculations.

The mycelium is doubtfully perennial in Ribes and certainly is
so in the bark of the pine.

352 THE FUNGI WHICH CAUSE PLANT DISEASE

C. comptonie Arth.

I (=Peridermium pyriforme) on Pinus trunks. III on Comp-
tonia.

The Peridermium is perennial in the trunks of the pine where
it does considerable injury. Clinton sowed eciospores from pine

Fic. 256.—Cronartium comptoniz (Peridermium) on
Pinus. After Clinton.

on Comptonia and in about twelve days the uredinia began
to appear.”

C. quercus (Brond.) Schr.

Hetercecious I (=Peridermium cerebrum) on pine. III on
oak.

Successful inoculations were first reported by Shear,’ later by
Arthur and Hedgcock.”*’ Globoid swellings 5-25 em. across are
formed on pine trees.

C. asclepiadeum (Wil.) Fries.

Hetereecious I (=Peridermium cornui) on Pinus silves-
tris.

II and III on Cynachum, Peonia, Gentiana and several other
hosts. European.

The mycelium is perennial in pine twigs and gradually kills
them.

THE FUNGI WHICH CAUSE PLANT DISEASE 353

Endophyllum Léviellé (p. 342)

The cycle of development includes only pycnia and telia, both
subepidermal.

O. Pycnia deep-seated, somewhat erumpent, flask-shaped, with
ostiolar filaments.

III. Telia bullate, definite, round, pulverulent. Peridium evan-
escent, cells resembling spores but flattened. Spores catenulate or
seemingly compacted without order, 1-celled, globoid to ellip-
soid; wall colored, medium thick, verrucose.

E. sempervivi (Alb. & Schw.) D. By.

Pycnial and telial stages on species of Sempervivum. Myce-
lium perennial in the host.

Pucciniaceze (p. 335)

Teliospores stalked (stalk sometimes short or evanescent)
1-celled or with several cells in a row or several united to form a
parasol-like head on a compound stalk; separate or gelatinous-
embedded. Basidiospores formed from promycelia. A‘cia with
or without peridia. Urediniospores solitary.

This is the largest and most important family of the order, in-
testing numerous valuable agricultural plants and causing enor-
mous loss. The species are manifold and the complexities owing to
polymorphism, hetercecism and biologic specialization are very
great.

Key To GENERA OF Pucciniacee

Teliospores united into a head on compound
pedicles, or several sessile or stalked on
a common simple pedicel; sori subcutic-
ular or subepidermal; uredinia when
present without peridium or encircling
paraphyses.
Teliospores united into a head on a com-
pound pedicel. ................... 1. Ravenelia.
Teliospores free, 1-4 on a simple pedicel,
all but one lateral
Teliospores flattened laterally. ....... 2. Dicheirinia.

354 THE FUNGI WHICH CAUSE PLANT DISEASE

Teliospores flattened above and be-
LOWS vals ou Saeed dae mae
Teliospores not flattened, but uredinio-
spores flattened laterally. ........
Teliospores free, 2-8 at apex of a common
stalk
With all spore forms. ...............
With pyenia and telia only..........
Teliospores not borne on a common pedicel,
or united into heads.
Teliospore wall with a more or less evi-
dent gelatinous layer.
Teliospores with evident gelatinous
layer, pores lateral
Teliospores 3-celled. ..............
Teliospores 2-celled. ..............
Teliospores with obscure gelatinous
layer, pores apical.
Teliospores with appendaged pedi-
Cel 822.5 555 Aeeecocmiassai tle neti alee
Teliospores without appendaged
POdIcels: «vec scadwey aera
Teliospore wall without gelatinous layer
Pycnia subcuticular, other sori sub-
epidermal; ecia when present with-
out peridium; uredinia when pres-
ent without peridium, but usually
with encircling paraphyses.
Teliospores mostly tuberculate, the
pores more than one and lateral
Teliospores 1-celled.. ...........
Teliospores with 3 or more cells
clustered at the apex of the
pedicel
Teliospores 3-celled. ..........
Teliospores more than 3-celled .
Teliospores with more than three
cells lineally arranged... ....
Teliospores mostly smooth, the pores
one in a cell and apical.
Teliospores 1-celled. ............

3. Pileolaria.

4.

10.

11.

Hemileia, p. 355.

. Tranzschelia, p. 356.
. Polythelis.

. Phragmopyxis.

. Uropyxis.

. Prospodium.

Nephlyctis.

Trachyspora.

12. Triphragmium, p. 358.
13. Spherophragmium.

14. Phragmidium, p. 358.

15. Spirechina.

THE FUNGI WHICH CAUSE PLANT DISEASE 355

Teliospores 2-celled......... 16. Gymnoconia, p. 359.
Teliospores 3 or more-celled.
Without uredinia.......... 17. Kenodochus, p. 361.
Without a@cia............ 18. Kuehneola, p. 361.

Sori all subepidermal; cia when
present with a peridium; ure-
dinia when present with no
peridium or rarely with en-
circling paraphyses.
Teliospores embedded in a more
or less gelatinous matrix.. 19. Gymnosporangium, p. 361.
Teliospores not embedded in a
gelatinous matrix.

Teliospores colorless......... 20. Eriosporangium.
Teliospores colored
Teliospores 1-celled....... 21. Uromyces, p. 371.
Teliospores 2-celled. ...... 22. Puccinia, p. 375.

Hemileia Berkley & Brown (p. 354)

Cycle of development imperfectly known; only uredinia and
telia recognized, both subepidermal.

II. Uredinia formed beneath the stomata, erumpent, without
peridium or paraphyses, spores borne singly on short pedicels,
which arise from a protruding hymenium of agglutinated hyphe,
obovate, laterally flattened and dorsiventral; wall pale-yellow,
smooth on ventral side, papillose on dorsal side, pores obscure or
absent.

III. Telia replacing the uredinia. Spores borne singly on pedi-
cels, 1-celled, napiform; wall nearly or
quite colorless, smooth.

H. vastatrix Berk. & Br.

II. Hypophyllous, thickly scattered, 1
or rarely somewhat circinate, very small, oalty
about 0.1 mm. across, light-orange fading ,,, Oe Dicken er EER
to pale-yellow, pulverulent, projecting ihe 4 ured n ae
through stomata and rarely rupturing and Ward. ‘

‘the epidermis; spores bilateral, slightly
obovate, flattened on the ventral side, 20-28 by 30-40 u; wall
pale-yellow, 1-1.5 u thick, rather thickly and very coarsely papil-

356 THE FUNGI WHICH CAUSE PLANT DISEASE

lose on dorsal side with bluntly pointed tubercles 2-4 yw long,
1-1.5 w in diameter, ventral side smooth, pores obscure.

III. Hypophyllous, arising from uredinia, thickly scattered,
very small, about 0.1 mm. across, pale-yellow; spores napiform
or globoid, somewhat umbonate above; wall pale-yellow or seem-
ingly colorless, thin, 1 y, slightly if any thicker above, smooth;
pedicel hyaline, one-half to once length of spore, slender.

It constitutes a serious coffee parasite in the orient and is re-
ported also from Porto Rico.

H. woodii K. & C. is a serious coffee parasite and occurs also on
Vanguieria edulis.

H. oncidii Griff & Maub. is on cultivated Oncidiums in France.

Tranzschelia Arthur (p. 354)

Cycle of development includes pyenia, ecia, uredinia and telia,
with alternating phases; autcecious or hetercecious. Pyenia sub-
cuticular, other sori subepidermal.

O.I. Pyenia depressed-conical or hemispherical; hymenium flat.

A&cia erumpent, cylindrical. Peridium dehiscent at apex, be-
coming recurved. A‘ciospores globoid; wall colored, finely ver-
rucose.

II. Uredinia erumpent, definite, without peridium. Uredinio-
spores borne singly on pedicels, with paraphyses intermixed,
obovoid, somewhat narrowed at both ends; wall colored, usually
paler below, echinulate; pores equatorial.

III. Telia erumpent, definite, pulverulent, without peridium.
Teliospores forming heads or balls by being attached by short,
fragile pedicels to a common stalk, which is short and incon-
spicuous, 2-celled by transverse septum, cells rounded and easily
falling apart, wall colored, verrucose.

T. punctata (Pers.) Arth.®! 24 282 233

I (=Acidium punctatum). Peridia uniformly scattered over
the whole of the foliage, hypophyllous, flat, semi-immersed,
with torn yellowish edges. Spores subglobose, pale yellowish-
brown, 15-24 uw in diameter. Pyenia scattered, blackish, puncti-
form.

II. Uredinia light-brown, small, round, crowded, pulverulent,
often confluent. Spores ovate or subpyriform, apex darker,

THE FUNGI WHICH CAUSE PLANT DISEASE 357

thickened, bluntly conical, closely echinulate, brown, 20-35 x
12-16 w, mixed with numerous capitate brownish paraphyses.
III. Telia pulverulent, dark-brown, almost black. Spores con-
sisting of two spherical cells, flattened at their point of union,
the lower cell often being smaller and paler. Epispore uniformly

x

Fic. 258.—T. punctata, urediniospores.

After Holway.

thick, chestnut-brown, thickly studded with short stout spines.
Spores 30-45 x 17-25 p. Pedicels short, colorless.

Hetercecious: O and I on Hepatica and Anemone.

II and III on Prunus sps., peach, almond, plum, cherry, apri-
cot.

Widely distributed in North America, Europe and Asia and
apparently introduced into Australia about 1883. The ecial stage
is perennial. Urediniospores have also been shown to remain viable
over winter. The peculiar character of the urediniospores has
sometimes led this fungus to be mistaken for a Uromyces.

In 1904, Tranzschel °° made cultures of the «cial stage from
Anemone on various Prunaceous hosts. Arthur made similar
inoculation from Hepatica in 1906.

358 THE FUNGI WHICH CAUSE PLANT DISEASE

Triphragmium Link (p. 354)

Teliospores 3-celled, one basal, two apical, each cell with one
or more germ tubes.

T. ulmarie Schm. occurs on Ulmaria in England and at one
station in America.

Phragmidium Link (p. 354)

O. Pyenia present.
I. Aciospores in basipetal chains. The first two spore forms

Fig. 260.—Phragmi-

dium bulbosum,

: : teliospore germi-

Fic. 259.—Triphragmium ulmariz, germi- nating. After Tu-
nating teliospore. After Tulasne. lasne.

are in pulverulent sori, surrounded by clavate or capitate, hyaline
paraphyses.

II. Urediniospores single.

III. Teliospores separate, pedicellate, consisting of from three
to ten superimposed cells, the uppermost of which has a single
apical germ pore, the others about four each, placed laterally.

The ecial stage is a Caoma but with a border of incurved pa-

THE FUNGI WHICH CAUSE PLANT DISEASE 359

raphyses. The unicellular urediniospores are similarly surrounded,

and bear numerous germ pores. The genus is limited to Rosaceous
hosts and its species are autcecious.

Eight American forms are recognized by Arthur 2 on roses as
follows:

P. montivagum Arth., P. discifloram (Tode) James, P. ameri-

000000

SQN
==((i 0)

‘ 8
2
8

Fic. 261.—Uredinio- and teliospores of; 1. P. americanum; 2. P. rosx-setigere; 3. P. rose
californice; 4. P. rose-arkansanz; 5. P. montivagum; 6. P. disciflorum. After Arthur.
canum Diet., P. rose#-setigere Diet., P. rose-californice Diet.,
P. rose-arkansane Diet., P. subcorticinum (Schr.) Went. and

P. rose-acicularis Siro.

They are mostly on wild roses and of but little economic im-
portance.

P. violaceum (Schul.) Went. is often serious on Rubus in
Europe.

P, rubi-idei (Pers.) Wint. is found on raspberries in Europe.

P. speciosum Fr. on rose has been separated by Arthur ‘as
Earlea speciosa on account of its non-gelatinous teliospore pedi-
cel, its large compact caulicolous telia and the absence of uredinia.

Gymnoconia Lagerheim (p. 355)
O. Pyenia conic.
I (=Czoma), peridia and paraphyses none.
III. Spores as in Puccinia.
This genus bears a superficial resemblance to Puccinia but is
easily distinguished by its naked zcial sori.

360 THE FUNGI WHICH CAUSE PLANT DISEASE

G. interstitialis (Schl.) Lag.?7?7"# 241

O. Pyenia glandular, numerous mostly epiphyllous.

I (=Czoma nitens), hypophyllous, sori irregular, confluent;
spores orange-red, globose to elliptic, epispore thin, 18-35 x 12-24.

III. Telia hypophyllous, few, sparse, cinnamon-brown; spores
more or less angular, 36-45 x 22-27 y, pedicel short or wanting.

Autcecious, on raspberries and blackberries, wild and cultivated,
in United States, Canada, Europe and Asia.

The pycnial stage appears first in spring giving to the leaves
and stems a glandular appearance. About two or three weeks

FIG.

&
Fic. 262.—G. interstitialis, ceoma sorus. After Newcomb.

later the axcial stage is visible on the lower surface of the leaves;
the epidermis soon ruptures and the orange beds of spores show.
The pycnia are then fully developed. The affected plants are
much stunted and are unproductive but are not killed. The
fungous mycelium is intercellular, growing rapidly into formative
tissues and perennating 7 in the woody shoots. The knob-like
haustoria penetrate the cells and often lie against the nuclei. The
mycelium is especially abundant in the pith near the bundles.
The eciospores may germinate at once and infect susceptible
hosts. The teliospore which is less conspicuous and therefore
rarely seen is of the Puccinia type. The telia appear in July

THE FUNGI WHICH CAUSE PLANT DISEASE 361

and August, usually hypophyllous, and the sori are very small
and inconspicuous.

Artificial infection of Rubus with the spores of the Ceoma stage
by Tranzschel 7 gave rise to the telial form, demonstrating
the identity of the two. Cultures were also made by Clinton
about the same time.

Xenodochus Schlecht (p. 355)

A®ciospores catenulate; uredinia wanting; teliospores short-
pedicelled, several celled in linear arrangement.
X. carbonarium Schl., autcecious on Sanguisorba in Europe.

Kuehneola Magnus (p. 355)

AKcia wanting; uredinia pulvinate, telia similar to Phragmidium
but with smooth spores with the germ pores apical.

K. uredinis (Lk.) Arth.

II. (=Uredo muelleri.) Uredinia lemon-yellow, minute dots;
spores globose to elliptic, about 26 y, hyaline, slightly verrucose.

III. Telia solitary, pale, 250-500 » broad; spores 5 to 6 to
12-celled, epispore hyaline, cells 17-47 x 15-26 yu; basidiospores
8.5-9.5 py.

The telia are pale yellowish-white, thus readily distinguishing
them from other Rubus rusts.

The uredinia are common and sometimes injurious on Rubus.
The sori are small and scattered.

K. gossypii (Lagerh.) Arth. is reported on cotton in British
Guiana,”” also Florida, Cuba and Porto Rico.

Gymnosporangium Hedwig f.%%7!) 21% *17 (p, 355)

Cycle of development including pycnia, ecia and telia, with
distinct alternating phases; hetercecious and autcecious. Pycnia
and other sori subepidermal.

O. Pyenia deep-seated, usually globoid, generally prominent
and conspicuous, at first honey yellow, usually becoming blackish,
globose or flattened-globose, with ostiolar filaments.

I (=Reestelia) erumpent, at first cylindric. Peridium dingy
white, usually elongated into a tubular form, membranous, tending

362 THE FUNGI WHICH CAUSE PLANT DISEASE

to rupture by longitudinal slits along the sides; peridial cells im-
bricate and often articulated, occasionally hygroscopic, outer walls
smooth, rather thin, inner walls smooth, verruculose, verrucose,
rugose, or spinulose. Mciospores in basipetal chains with alter-
nate barren cells, enclosed in a peridium, globoid to broadly ellip-
soid; wall colored, verrucose, usually with numerous, scattered,
evident germ pores.

III. Telia erumpent, naked, usually definite, variously shaped,
gelatinous and elastic at maturity, expanding considerably when
moistened. Teliospores chiefly 2-celled, in some species 3, 4, or

Fia. 263.—Gymnosporangium, spore masses just emerging.
After Heald.

5-celled, by transverse septa; walls colored, of various thickness,
smooth; pores usually two in each cell, sometimes, 1, 3, or 4, vari-
ously arranged; pedicels hyaline, elastic, usually of considerable
length, cylindric, rarely carotiform, walls thick, the outer portion
swelling and becoming gelatinous to form a jelly-like matryx in
which the spores appear embedded.

All of the species agree in possessing the same spore forms,
pyenia, cia, and telia which appear in the same sequence in
the different species; also, in the fact with two exceptions, that
the cia grow on pomaceous plants and the telia on Juniperus
(with few exceptions).

THE FUNGI WHICH CAUSE PLANT DISEASE 363

The sciospores are borne in ecia which rest in orange or
yellow spots often strongly thickened. Pycnia abound. The
ecium with its thick peridium is erumpent and projects to
some distance above
the host surface, this
character giving rise
to the separate form-
genus, Reestelia. The
peridial margin which
may be lacerate or
fimbriate is used in
specific characteriza-
tion. The spores are
borne and function as
in ordinary cia.
They bear several germ
pores.

AKciospores germi-
nate at once and if
they fall upon suitable
coniferous hosts bring
about infection. The
mycelium penetrating
the leaf or branch
often induces large
hypertrophy.

In spring in moist
weather the _ telio-
spores are found in
Se a eae Fic. 264.—Gymnosporangium teliospores. a, G. cla-
posed of the spores, varisforme; b, G. globosum; c, G. macropus; d, G.
which are usually nidus-avis; e, G. nelsoni; f,G. clavipes. After King.
orange or yellow, and of their long gelatinous pedicels.

Each cell usually bears several germ pores near the septum
through one of which the tube emerges.

The teliospores germinate immediately in situ by typical
4-celled promycelia and four basidiospores are produced on each
promycelium.

364 THE FUNGI WHICH CAUSE PLANT DISEASE

The basidiospores are capable of infecting only the appropriate
alternate host and that when the parts are still young and
tender.

An abnormal development of germ tubes instead of the usual
promycelium has been reported in some instances. According
to Lloyd & Ridgway *? several crops of basidiospores are pro-
duced in one season.

The various species usually make good subjects with which to
study infection. The teliospore masses placed in water soon
become covered with basidiospores. Suspensions of these in water
applied to susceptible hosts usually give positive results readily.

G. juniperi-virginianz Lk. 7 ?!5 214(=G. macropus) Schu.

O. Pycnia epiphyllous.

I. Hcia (=Reestelia pyrata) chiefly hypophyllous, usually in
annular groups, on thickened discolored spots, at first cylindric,
0.1-0.4 mm. in diameter;
peridium splitting extremely
early, becoming fimbriate to
the base, strongly revolute;
peridial cells usually seen
only in side view, long and
narrow, 10-16 x 65-100 u,
becoming much curved when
wet, inner and side walls
rather sparsely rugose with
ridges extending half way
across the side walls; xcio-
spores globoid or broadly
ellipsoid, 16-24 x 21-31 ug,
wall light chestnut-brown,
2-3 yw thick, finely verru-
cose.

SS III. Telia appearing on

Fic. BES eer yea hes aecia. globoid or reniform galls

5-30 mm. or more in diam-
eter, evenly disposed, cylindric or cylindric-acuminate, 1.5-3 mm.
in diameter by 10-20 mm. long, golden-brown; teliospores 2-celled,
rhombic-oval or narrowly ellipsoid, 15-21 x 42-65 nu; shghtly or

THE FUNGI WHICH CAUSE PLANT DISEASE 365

not constricted at the septum, wall pale cinnamon-brown, thin,
about 1 4; pedicel cylindric, 3-5 » in diameter; pores two in
each cell near the septum.

I. Acia on apple both wild and cultivated.

III. Telia on Juniperus virginiana and J. barbadensis.

Destructive, particularly in East and South.

Sporidia are matured in twelve to twenty-four hours after the
spore-masses expand by moisture and as soon as the sori begin to
dry they are carried away by wind and on suitable hosts infect
through the cell walls by appresoria. Two or three crops of sporidia
may arise in one season but the first crop is largest.2!4 Each crop
may result in a corresponding crop of «cia. The stage on apple
fruits shows as pale-yellow spots of pinhead size about seven
to ten days after infection. The spots finally become orange-
colored and in a few weeks the pycnia appear as black specks.
On leaves hypophyllous cushions 0.5-1 cm. in diameter form on the
spots and bear the excia, the mature tubes of which are split and
recurved giving a stellate appearance. Aiciospores pass back to
the cedar in summer and cause infection. The mycelium here
remains practically dormant according to Heald 2!‘ until the fol-
lowing spring when the telial galls first become visible. These
galls grow throughout the summer, mature in the fall, and give
rise to the teliospores during the next spring. The mycelium is
thus seen to be biennial.

G. clavarizforme (Jacq.) D. C, %% 2% 211

I. Acia hypophyllous, fructicolous or caulicolous, usually
crowded in small groups 2-3 mm. across on the leaf blades, some-
times in larger groups on the veins, petioles and twigs, often
densely aggregated on the fruits and occupying part or all of the
surface, cylindric, 0.7-1.5 mm. high by 0.3-0.5 mm. in diameter;
peridium soon becoming lacerate, usually to base, erect: or spread-
ing; peridial cells long and narrow, often becoming curved when
wet, linear in face view, 18-30 x 80-13 uy, linear or linear-oblong
in side view, 15-25 u thick, outer wall 1-2 u thick, smooth, inner
wall and side walls 5-7 u» thick, rather coarsely verrucose with
roundish or irregular papilla of varying sizes; eciospores globoid,
21-27 x 25-30 yu, wall light cinnamon-brown, 2.5-3.5 u thick,
moderately verrucose.

366 THE FUNGI WHICH CAUSE PLANT DISEASE

III. Telia caulicolous, appearing on long fusiform swellings of
various sized branches, numerous, scattered, or sometimes agegre-
gated, cylindric, or slightly compressed, 5-10 mm. long by 0.8-1.5
mm. in diameter, acutish, or sometimes forked at the apex,
brownish-yellow; teliospores 2-celled, lanceolate, 13-20 x 40-80 yu,

occasionally longer, rounded or narrowed
above, usually narrowed below, very
slightly or not at all constricted at the
septum, wall golden-yellow, thin, about
1 uw; pores 2 in each cell, near the sep-
tum.
I. Aicia on Crategus spp., Amelanchier,
4 Aronia, Cotoneaster, Cydonia, and Pyrus.
III. Telia on Juniperus communis, J.
Fic. 266. — Gymnosporan- oxycedrus, and J.sibirica. Spindle-shaped
wating Lk nore afer swellings occur on Juniper branches.

Richards. Cylindric spore-masses ooze through rifts
in the bark. Aéciospores shed in June germinate at once on Juniper
twigs and result in the following year in swellings which often
later cause death. In spring the spore-masses emerge and the
teliospores germinate in situ. Upon the Rosaceous hosts spots
appear eight to fourteen days after infection. Kienitz-Gerloff
reports the occasional formation of a germ tube instead of a
promycelium. This is, however, to be regarded as an abnormal
condition.

G. globosum Farl. 7 213 215 216

O. and I. Atcia chiefly hypophyllous and crowded irregularly
or rarely in approximately annular groups 2-7 mm. across, cylin-
dric, 1.5-3 mm. high by 0.1-0.2 mm. in diameter; peridium soon
splitting in the upper part, becoming reticulate half way to base;
peridial cells seen in both face and side views, broadly lanceolate
in face view, 15-23 x 60-90 yu, linear rhomboid in side view, 13-19 z
thick, outer wall about 1.5 » thick, smooth, inner and side walls
3-5 yw, thick, rather densely rugose with ridge-like papille of
varying length; eciospores globoid or broadly ellipsoid, 15-19 x
18-25 yu, wall light chestnut-brown, 1.5-2 y thick, finely verru-
cose.

III. Telia caulicolous, appearing on irregular globoid, gall-like

THE FUNGI WHICH CAUSE PLANT DISEASE 367

excrescences 3-25 mm. in diameter, unevenly disposed, often
separated by the scars of the sori of previous seasons, tongue or
wedge-shaped, 1.5-3 mm. broad by 2-5 mm. long at the base and
6-12 mm. high, chestnut-brown; teliospores 2-celled, ellipsoid,
16-21 x 37-48 yu, somewhat narrowed above and below, slightly
constricted at the septum, wall pale cinnamon-brown, 1-2 u
thick; pores 2 in each cell, near the septum.

I. Acia on apple, pear, Crategus, quince, mountain ash.

III. Telia on Juniperus virginiana and J. barbadensis. Common
and widely distributed in eastern America.

The telial galls are from 0.5 to 2.5 cm. in diameter, very ir-
regular. In late spring dark-brown spore-masses, later yellow-
orange, 0.5 to 2.5 cm. long appear.

The Reestelia spots are 0.5-1.0 cm. across. Pycnia blackish
above. The ecia are on thickened hypophyllous spots, long,
slender, soon splitting and becoming fimbriate. Mesospores occur
occasionally. The eciospores germinate on the cedar. The
mycelium stimulates the hosts to extra formation of parenchy-
mateous tissue.

G. juniperinum (L.) Mart.

I. Acia (=Reestelia penicillata [Pers.] Fries.) hypophyllous,
in annular or crowded groups, 2-5 mm. across on large thickened
discolored spots, at first cylindric, 0.5-1.5 mm. high, 0.5-1 mm. in
diameter; peridium soon becoming finely fimbriate to base and
somewhat twisted or incurved; peridial cells usually seen only in
side view, rhomboid, very thick, 30-35 x 60-90 u, outer wall
medium thin, 2-3 », smooth, inner wall medium thick, 7-10 uy,
rugose, side walls very coarsely rugose with thick, somewhat
irregular ridges, roundish or elongate ridge-like papille inter-
spersed; eeciospores globoid, very large, 28-35. x 30-45 u, wall
chestnut-brown, thick, 3-5 yu, rather finely verrucose.

III. Telia caulicolous, appearing on hemispheric swellings
(1-4 em. long) breaking forth along the sides of the larger branches,
or on subglobose galls (1.5-2 cm. in diameter) on the smaller
branches, applanate, indefinite, usually of considerable size, often
covering the whole hypertrophied area, sometimes becoming
patelliform when expanded, chocolate-brown; teliospores 2-celled,
ellipsoid, 18-28 x 42-61 uy, usually slightly narrowed both above

368 THE FUNGI WHICH CAUSE PLANT DISEASE

and below, slightly or not constricted at the septum, wall cinnamon
brown, 1-1.5 yu, thick; pores usually 3 in upper cell, 1 apical, 2
near the septum, in the lower cell 2 pores near the septum.

O and I on apple and mountain ash.

III. Telia on Juniperus communis and J. sibirica. In Europe.

The teliospores occur on both twigs and leaves. Marked def-
ormation is caused by this stage on leaves and petioles.

G. clavipes C. & P. *8 (=G. germinale [Schw.] Kern).

I. Acia (=Reestelia aurantiaca) on stems and fruits, crowded
on hypertrophied areas of various size on the twigs and peduncles,
occupying part or nearly all of the surface of the fruits, cylindric,
1.5-3 mm. high by 0.3-0.5 mm. in diameter; peridium whitish,
becoming coarsely lacerate, sometimes to base, erect or spreading;
peridial cells seen in both face and side views, polygonal-ovate or
polygonal-oblong in face view, 19-39 x 45-95 yu, rhomboid in side
view, 25-40 u, thick, outer wall moderately thick, 3-5 yu, inner wall
very thick, 13-23 y, coarsely verrucose with loosely set, large,
irregularly branched papille, side walls verrucose on inner half
similar to inner wall; aeciospores globoid, large, 31-32 x 24-39 un,
wall pale yellow, thick, 3-4.5 uw, rather coarsely verrucose with
crowded slightly irregular papillz.

III. Telia caulicolous, appearing on slight fusiform swellings,
usually aggregated, roundish, 14 mm. across, often confluent,
hemispheric, 1-3 mm. high, orange-brown; teliospores 2-celled,
ellipsoid, 18-26 x 35-51 yu, roundish or somewhat acutish above,
obtuse below, slightly or not constricted at the septum, wall
yellowish, 1-2 » thick, slightly thicker at the apex; pedicles caroti-
form, 9-19 yw in diameter near the spore; pores one in each cell,
apical in the upper, near the pedicel in the lower.

I. Aicia on Amelanchier, Aronia, Cratzegus, Cydonia, and
apple.

III. Telia on Juniperus communis and J. sibirica.

G. cornutum (Pers.) Arth.

A rather uncommon species with I (=Reestelia cornuta [Pers.]
Fries) on Sorbus spp. and III on Juniperus communis and
J. sibirica. Ranging from New York to Wisconsin and northward;
also in the mountains of Wyoming and Colorado: Europe. Of no
considerable economic importance in America.

THE FUNGI WHICH CAUSE PLANT DISEASE 369

G. ellisii (Berk.) Farl.

I. Acium unknown. III. Telia on Cupressus thyoides. Prob-
ably of very small economic importance.

G. transformans (Ellis) Kern. (=Reestelia transformans
Ellis).

I. Acia on Pyrus arbutifolia, which is of no economic im-
portance. Confined to a small area from Massachusetts to New
Jersey.

III. Telia unknown.

G. nidus-avis Thax. 2 217

I. Acia amphigenous, especially fructicolous, cylindric, 2-4 mm.
high by 0.4-6.7 mm. in diameter; peridium soon becoming irregu-
larly lacerate usually to base, slightly spreading; peridial cells,
seen in both face and side views, lanceolate in face view, 15~23 x
55-88 y; linear in side view, 14-18 u, thick, outer wall 1-.5 p
thick, smooth, inner and side walls 5-7 » thick, coarsely rugose
with narrow ridges, with shorter, often roundish papille inter-
spersed; zeciospores globoid or broadly ellipsoid, 18-23 x 23-28 y,
wall cinnamon-brown, rather thick, 2.5-4 u, very finely verrucose,
appearing almost smooth when wet.

III. Telia caulicolous, often dwarfing the young shoots and
causing birds’ nest distortions, or witches’ brooms, usually causing
a reversion of the leaves to the juvenile form, sometimes appearing
on isolated areas on the larger branches and producing gradual
enlargements, solitary or rarely confluent, of variable size and
shape, roundish to oval on the young shoots, 1-2 mm. across, oval
to nearly elliptic on the woody branches, 1.5-3 mm. wide by
2~7 mm. long, pulvinate when young, becoming hemispheric, dark
reddish-brown; “teliospores 2-celled, ellipsoid,. 16-23 x 39-55 yn,
wall pale cinnamon-brown, rather thin, 1-1.5 yw, very slightly
thicker at apex; pores one in a cell, apical. Mycelium perennial
in leaves, branches or trunks of Juniperus virginiana very com-
monly inducing a “bird’s nest” distortion.

I. Atcia on Amelanchier and quince.

III. Telia on Juniperus virginiana.

G. sabinz (Dicks) Wint.

O and I (=Reestelia cancellata), on pear in Europe.

III. Telia on several Junipers.

370 THE FUNGI WHICH CAUSE PLANT DISEASE

The telial mycelium is perennial and causes swellings. From
these in spring ooze the gelatinous, transparent spore-masses.

The mycelium in Juniperus causes increase in wood-bast and
rind, thickened twisted tracheids, increase in number and thick-
ness of the medullary rays. No mycelium is found in the wood
itself.

G. biseptatum Ell.

I. Heia (=Reestelia botryapites) hypophyllous, usually in
groups of 2-8, rarely solitary, borne in gall-like pyriform protuber-
ances 1-1.5 mm. in diameter by 1.5-3 mm. high, cylindric, 0.50.8
mm. in diameter by 2-4 mm. high; peridium soon becoming finely
cancellate, not dehiscent at apex; peridial cells cylindric, hyphal-
like, 9-14 yw in diameter by 145-190 yu long, often irregularly bent,
outer, inner, and side walls of equal thickness, about 1.5-2 u,
whole surface smooth; eciospores globoid, small, 15-17 x 16-22 u,
wall dark cinnamon-brown, rather thick, 2.5-3 wu, moderately
verrucose.

Ill. Telia caulicolous, appearing on fusiform swellings, scattered,
oval or irregular, about 1.5-3 mm. wide by 2-7 mm. long, often
confluent, hemispheric, chestnut-brown; teliospores 2 to 4-celled,
13-19 x 35-77 yu, usually rounded above, somewhat narrowed be-
low, slightly constricted at the septa, wall pale-yellow, 1.1-5 xz
thick, pores 2 in each cell, near the septa.

I. Atcia on Amelanchier.

Ill. Telia on Chamzcyparis.

G. nelsoni Arthur. Aicia hypophyllous and fructicolous, usually
in small groups 1-2 mm. across, cylindric, 2-4 mm. high by 0.2-
0.3 mm. in diameter; peridium whitish, dehiscent at apex and
also rupturing more or less along the sides; peridial cells seen in
both face and side view, 18-35 x 75-115 yu, linear rhomboid in side
view, 16-35 yu, thick, outer wall rather thin, 1.5-2 yu, smooth,
inner and side walls rather thick, 7-12 y, evenly and densely
verruculose; zeciospores globoid, 19-26 x 21-29 y, wall chestnut-
brown, 2-3 yu thick, finely verrucose.

III. Telia caulicolous, appearing on firm, woody, globose galls
0.5-5 cm. in diameter, unevenly disposed, densely aggregated or
often separated by the scars of the sori of previous seasons, ir-
regularly flattened, about 1-1.5 mm. broad by 1-5 mm. long at the

THE FUNGI WHICH CAUSE PLANT DISEASE 371

base by 3-4 mm. high, often confluent, light chestnut-brown; telio-
spores 2-celled, narrowly ellipsoid, 18-26 x 50-65 yu, narrowed at
both ends, slightly constricted at the septum; wall pale cinnamon-
brown, 1-1.5 yw thick; pores two in each cell, near the sep-
tum.

I. Acia on Amelanchier, Peraphyllum, quince and pear.

III. Telia on Juniperus spp. :

Range; Alberta, south to Colorado and Arizona.

G. japonicum Syd. 2%

I. Aicia (=R. koreensis), on Pear.

III. Telia on Juniperus.

This form has been imported into America.

G. torminali-juniperinum (Ed.) Fischer.

This species has its ecial stage on species of Sorbus and its
telia on Juniperus in Europe. It is closely related to G. cor-
nutum of the northern part of our own continent, and of
Europe. ?

G. yamade Miyabe. Only the ecia of this species have been
found. It infests the apple and various other species of Malus in
Japan.

Uromyces Link (p. 355)

QO. Pyenia spherical with minute ostioles.

I. Acia with peridia, spores without pores.

II. Urediniospores generally with many germ pores, unicellular,
spherical, ellipsoid or variously shaped, usually rough.

III. Teliospores unicellular, pedicellate, with an apical germ
pore.

The unicellular teliospores may be distinguished from uredinio-
spores by their single apical germ pore, also usually by their
thicker walls and absence of the roughness so characteristic of
urediniospores.

The genus is a very large one, with hundreds of species, which ex-
hibit hetercecism, autcecism, biologic specialization and the various
types regarding spore forms that are noted on pages 324-327.

U. appendiculatus (Pers.) Lév.?”

I. AXciospores angularly globose, whitish, slightly punctulate,

372 THE FUNGI WHICH CAUSE PLANT DISEASE

17-32 x 14-20 ». II. Urediniospores pale-brown, aculeolate, 24-33
x 16-20 yu. III. Teliospores elliptical or subglobose, smooth,
dark-brown, apex much thick-
ened, with a small, hyaline, wart-
like papilla, 26-35 x 20-26 x.

An autcecious eu-type. On
Phaseolus, Dolichos and other
Sai related legumes.
keg The sori usually appear late

in the season on leaves, rarely on
stems and pods. The mycelium
G53 is local. Great difference in
Ae ~* pores varietal susceptibility is noted.
— U. pisi (Pers.) de B.™
Fic Sacer section of ure- 1 eee Oy PArIRGIE):
dinium of U. appendiculatus. After 4cia scattered over the whole

Wheteel. leaf surface. Peridia cup-shaped,
with whitish edges. Spores subglobose or polygonal, orange,
finely verrucose, 17-26 » in diameter.

II. Uredinia roundish, scattered or crowded, cinnamon-brown.
Spores subglobose or
elongate, yellowish-
brown, echinulate, 17-
20 x 20-25 uz.

III. Telia roundish
or elliptical, blackish.
Spores subglobose or
shortly elliptical, finely
but closely punctate,
apex only slightly
thickened, 20-30 x 17-
20 yw. Pedicels long,
colorless, fragile.

A hetercecious eu- Fic. 268—Diagrammatic section of teliospores of
type not found if U. appendiculatus. After Whetzel.
America: O and I on Euphorbia.

II and III on Lathyrus, Pisum, Vicia.

The ecial stage dwarfs the host in which it is perennial.

THE FUNGI WHICH CAUSE PLANT DISEASE 373

U. fabe (Pers.) De B.” This is an autoecious eu-type which
causes a rust of the broad bean, vetches, peas.

U. trifolii (Hed.) Lev.7**-?3 An autcecious eu-type.

I. Acia in circular clusters, on pallid spots. Peridia shortly
cylindric, flattish, on the stems in elongated groups; edges whit-
ish, torn. Spores subglobose or irregular, finely verrucose, pale-
orange, 14-23 uw in diameter.

II. Uredinia pale-brown, rounded, scattered, surrounded by the

Fic. 270.—Uredini- -
ospore and telio-
spore of Uromy-

diculatus, teliospore ger- ces trifolii. Af-

minating. After Tulasne. ter Cobb.

torn epidermis. Spores round or ovate, with three or four equa-
torial germ pores, echinulate, brown, 20-26 x 18-20 yu.

III. Telia small, rounded, almost black, long covered by the
epidermis. Spores globose, elliptical or subpyriform, with wart-
like incrassations on their summits, smooth, dark-brown, 22-30 x
15-20 p. Pedicels long, deciduous.

Cosmopolitan on white, crimson and alsike clovers. Stages
O and I are most common on Trifolium repens, least common on
T. incarnatum. Pycnia appear in early spring or even in winter.
The xciospores germinate readily in water and give infections which
give rise to urediniospores in about two weeks. Urediniospores
may be produced throughout the summer and may even survive
the winter. Teliospores are produced in the uredinia or in
separate sori late in the season. The teliospores by infection

374 THE FUNGI WHICH CAUSE PLANT DISEASE

give rise to the pycnial and ecial stages. Considerable distor-
tion arises in parts affected by either stage.

U. fallens (Desm.) Kern.2% A form on crimson, zig-zag and
red clover often confused with the last species.

O and I unknown.

II. Urediniospores with four to six scattered germ pores.

III. Teliospores similar to those of U. trifolii.

U. medicaginis Pass.

O and I. Pycnia and ecia as in U. pisi.

Il. Uredinia chestnut-brown, spores globose to elliptic, 17-
23 yu, light-brown.

Fic. 271.—Uredo stage of U. beta. After Scribner.

III. Telia dark-brown, spores ovate-elliptic or pyriform 18-28 x
14-20.

A hetercecious eu-type. I, on Euphorbia; in Europe.

II and III on alfalfa and clovers in Europe and America.

U. minor Schr. is an autcecious opsis-type, I and III on Trifo-
lium montanum.

U. beta (Pers.) Tul.®® *** An autcecious eu-type; on members
of the genus Beta both wild and cultivated. In the United States
observed only in California. Recorded in Europe, Africa, Australia.

U. kuhnei Krug. occurs on sugar cane.?”°

U. dactylidis Otth. is a hetercecious eu-type; II and III on
Phleum, I on Ranunculus, in Europe.

U. poz Rab. is a hetercecious eu-type; I on Ranunculus and
Ficaria; II and III on Poa.

THE FUNGI WHICH CAUSE PLANT DISEASE 375

U. caryophyllinus (Schr.) Wint.2262

I. Acia on Euphorbia in Europe.

II. Uredinia sparse, confluent on stems, spores round, elliptic
or oblong, 40 x 17-28 u, light-brown.

III. Teliospores globose, irregular or ovoid, apex thickened 23-
35 x 15-22 mm., pedicel 4-10 yu.

II and III on cultivated carnations and several other members
of the genus Dianthus. I on Euphorbia gerardiana. It has been
known in Europe since 1789 but was not noted in the United States
until 1890 when it was found by Taft at Lansing, Mich. It soon
invaded the whole country causing great loss. There is large racial
difference in host susceptibility.

The urediniospores germinate readily in water and serve to
propagate the fungus. Studies of the effects of toxic substances
upon these have been made by Stevens 9 and by Stewart.?” The
ecial stage has recently been recognized by Fischer °° as Al.
euphorbie-gerardiane.

Less important species are: U. ervi (Wallr.) Plow. an autcecious
eu-type on Vicia in Europe; U. erythronii (D. C.) Pass. an opsis-
type occasional on cultivated Lilium in Europe. U. ficarize Schw.
is on Ficaria; U. pallidus Niess. a lepto-type on Cytisus; U. scil-
larum (Grev.) Wint. a micro-type on Scilla and Muscari. U. jaf-
frini Del. is reported on vanilla; 7*! U. colchici Mas. on Colchinum
speciosum in Europe.

Puccinia Persoon (p. 355)

O, I, II, as in Uromyces.

III. Teliospores separate, pedicellate, produced in flat sori,
consisting of two superimposed cells each of which is provided
with a germ pore. The superior cell has its germ pore, as a rule,
piercing its apex; in the inferior or lower the germ pore is placed
immediately below the septum.

Mesospores (p. 327) are not rare. They are merely teliospores
with the lower cell wanting, and function as teliospores.

Some one thousand two hundred twenty-six species are enumer-
ated by Sydow © presenting great diversity in spore relation,
hetercecism and biologic variation.

376 THE FUNGI WHICH CAUSE PLANT DISEASE

P. cerasi Ces. is a hemi-type on cherries in Southern Europe.

P, ribis-caricis Kleb.

I on Ribes. II and III on Carex.

Klebahn 7** differentiates five species of Puccinia on Ribes be-
longing to the Ribis-Carex group. These are P. pringsheimiana
(I.=. grossulariz.) P. ribis-pseudocyperi, P. ribis nigri-acute,
P. ribis nigri-paniculate and P. magnusii.

P. asparagi D. C.?°>?4

I. Peridia in elongated. patches upon the stems and larger
branches, short, edges erect, toothed. Spores orange-yellow,
round, very finely echinulate, 15-26 u» in
diameter.

II. Uredinia brown, flat, small, long
covered by the epidermis. Spores irregu-
larly round or oval, clear-brown, echinu-
late. 18-25 x 20-30 yu.

IlI. Telia black-brown, compact, pul-
vinate, elongate or rounded, scattered.
Spores oblong or clavate, base rounded,
apex thickened, darker, central con-
striction slight or absent, deep chest-
nut-brown, 35-50 x 15-25 yu. Pedicels
“41 persistent, colorless or brownish, as long
oe eat tule, chegn a8 or longer than the spores.

ing teliospores of P. as- An autcecious eu-type on Asparagus,

aca car cultivated and wild. The fungus has
been known in Europe since 1805 but did not attract attention
in the United States until 1896 in New Jersey **° when it began
its devastating westward migration **1 across the country reaching
California in 1900 or 1901.

The ecial stage appears in early spring; the eciospores may
germinate at once or if dry remain viable for several weeks,
their germ tubes penetrating the host in most cases stomatally.
The uredinia appear in early summer soon after or with the ecial
stage and, wind borne, distribute the fungus. The uredinio-
spores remain viable a few months when dry. The telial stage
appears late in the season and germinates only after hibernation.

Unicellular spores, mesospores, are sometimes met.

THE FUNGI WHICH CAUSE PLANT DISEASE 377

P. bullata (Pers.) Schr. is a brachy-puccinia which is autcecious
on celery, parsley, dill and other umbellifers.

P. apii (Wallr.) Cda. also occurs in its uredinial and telial stages
on celery. : .:

P. castagnei Thiim is recorded for eelery in France.

P. allii (D. C.) Rud. is-a hemi-type on cultivated onions.

P. porri Sow. is an autcecious rust which is sometimes. de-
structive to onions in
Europe.

P. endivie Pass.?*”
occurs on- endive in
Italy and America.

P. phragmitis
Schum. ?43°244

I (=. rubellum).
Peridia on circular.
red spots 0.5-1.5’em. — Fic. 278.—Cross-section of wcia of P. asparagi.
in diameter, shallow, , nea
edges white, torn. Spores white, subglobose, echinulate, 15-16
in diameter.

II. Uredinia rather large, dark brown, elliptical, pulverulent,
without paraphyses. Spores ovate or elliptical, echinulate, brown,
25-35 x 15-23 yp.

III. Telia large, long, sooty black, thick, often confluent.
Spores elliptical, rounded at both ends, markedly constricted in
the middle, dark blackish-brown, smooth, 45-65 x 16-25 wu. Pedi-
cels very long, 150-200 x 5-8 y, yellowish, firmly attached.

Hetercecious; I on Rumex and rhubarb, II and III on Phrag-
mitis. Found only rarely in America,”** ?44 except in the middle
west.

P. cyani (Schl.) Pass. is on cultivated Centaurea.

P. tragopogonis (Pers.) Cda. “

I. Acia on the whole plant—leaves, stems, bracts, receptacles
—shortly cylindrical, at first mammeform, peridia with whitish,
torn edges. Spores rounded, verrucose, orange-yellow, 18-27 uz,
sometimes as much as 35 uw long. Mycelium diffused throughout
the host-plant.

III. Telia brown, few, small, scattered, elliptical or elongate,

378 THE FUNGI WHICH CAUSE PLANT DISEASE

long covered by the epidermis. Spores broadly oval, often
almost globose, slightly constricted, apex not thickened, thickly
verrucose, brown, 26-48 x 30-35 yu. Pedicels short, colorless,
deciduous. Mycelium localized.

An opsis-type on cultivated Tragopogon. Urediniospores are
unknown. The teliospores are often unicellular and are very
variable.

P. taraxaci Plow. is common on dandelion. P. cichorii Pass. is a
hemi-type on Cichorium. P. isiacee on Phragmitis is thought to be

Fig. 274.—P. graminis, telium and germinating
teliospore. After Carleton.

the telial stage of AE. brassice on cabbage. 7 P. fagopyri Barcl.
is found on buckwheat.

P. menthe Pers.

I. Acia with peridia immersed, flat, opening irregularly, edges
torn; principally on the stems, which are much swollen, more
rarely on concave spots on the leaves. Spores subglobose or
polygonal, coarsely granular, pale-yellowish, 17-26 x 26-35 yu.

II. Uredinia small, roundish, soon pulverulent and confluent,
cinnamon-brown. Spores irregularly rounded or ovate, echinu-
late, pale-brown, 17-28 x 14-19 py.

III. Telia black-brown, roundish, pulverulent. Spores ellip-
tical, oval, or subglobose, central constriction slight or absent,
apex with a hyaline or pale-brown papilla, verrucose, deep-brown,
26-35 x 19-23 u. Pedicels long, delicate, colorless.

An autcecious eu-type on many mints.

THE FUNGI WHICH CAUSE PLANT DISEASE 379

P. graminis Pers. 45, 166-182, 246, 306, 322

I (=. berberidis). Spots generally circular, thick, swollen,
reddish above, yellow below. Peridia cylindrical, with whitish
torn edges. Spores subglobose, smooth, orange-yellow, 15-25 y.

II. Uredinia orange-red, linear, but often confluent, forming
very long lines on the stems and sheaths, pulverulent. Spores
elliptical, ovate, or pyriform, with four very marked, nearly
equatorial germ pores, echinulate, orange-yellow, 25-38 x 15-20 p.

III. Telial persistent, naked, linear, generally forming lines on
the sheaths and stems, often confluent. Spores fusiform or clavate,
constricted in the middle, generally attenuated below, apex much
thickened (9-10 u), rounded or pointed, smooth, chestnut-brown,
35-65 x 15-20 u. Pedicels long, persistent, yellowish-brown.

O and I on Berberis and Mahonia.

II and III on Avena, Hordeum, Secale, Triticum and nearly
fifty other grasses. Of great importance on wheat in the Great
Plains and along the Ohio.

This fungus was the subject of the classic researches of de
Bary begun in 1865 and has since repeatedly served as the basis
of fundamental investigations in parasitism, cytology and biologic
specialization. That the barberry exciospores can bring about
cereal infection seems to have been shown as early as 1816. 1%
Inoculations in the reverse order were made in 1865. 1° Extensive
studies by Eriksson "4 are interpreted by him to show that what
was formerly regarded as one species must be separated on bio-
logic grounds into several races which he finally erects as species,
though others do not agree that their rank should be specific.
These are: P. graminis secalis. P. graminis avene. P. graminis
tritici. P. graminis aire. P. graminis pox. P. phlei-pratensis.

These words from Butler and Hayman *” show the complexity
of the status of these biologic forms.

“Of late years it has become more and more established that
parasitic fungi, which are capable like these rusts of living on
several hosts, tend to develop ‘races’ on their different host-
species, marked off from each other by definite characters. Some-
times the characters are such as are capable of being detected
microscopically. Usually, however, the fungi are, to all appear-
ance, identical, and differences only appear when their manner of

380 THE FUNGI WHICH CAUSE PLANT DISEASE

life is carefully studied. The chief of these is the incapacity of a
race to attack the host-plants of another race. Such forms as
are thus outwardly identical but which show a constant difference
in their mode of life are known as “biological’’ species or as forme
speciales.

“A specialized form is considered to be ‘sharply fixed’ or ‘not
sharply fixed’ according as it is wholly incapable, or sometimes
capable, of attacking the host-plants of the other specialized forms
of the same fungus. Thus the P. graminis of wheat (P. graminis
j. sp. Tritici) is not sharply fixed, for it can attack barley, rye,
&c., sometimes. The P. graminis found on grasses of the genus
Agrostis (P. graminis f. sp. Agrostis) is sharply fixed, for it attacks
this genus only and does not pass to the other grasses on which
it has been tried.

“But even the not sharply fixed forms, such as the P. graminis
of wheat, may be entirely incapable of attacking some of the
species which bear other forms of the same fungus. In other
words a form may be not sharply fixed in regard to some host-
plants and sharply fixed in regard to others. A striking instance
of this occurs in India. P. graminis can be divided amongst others
into races on wheat (f. sp. Tritici), rye and barley (f. sp. Secalis),
and oats (f. sp. Avene). Thef. sp. Tritici can attack barley some-
times, and did so in four out of sixteen of our inoculations, but it
does not, in India at least, attack oats. Hence it is sharply fixed
in regard to oats and not sharply fixed in regard to barley. The
f. sp. Secalis on barley also does not pass to oats, but infected
wheat doubtfully in two out of sixteen inoculations. These two
forms are common in India, and ‘the practical bearing of their
not passing to oats is considerable, for the f. sp. Avene has not
yet been observed in this country.”

The mycelium branches intercellularly and bears small haus-
toria which penetrate the cells. In the barberry it is local. The
epiphyllous pycnia appear first followed soon by the mainly.
hypophyllous ecia. The flask-shaped pycnia at maturity bear
numerous pycniospores and exserted paraphyses. Their hyphe
are orange-tinted, due to a coloring matter in the protoplasm or
later in the cell walls.

The egcium originates in the lower region of the mesophyll

THE FUNGI WHICH CAUSE PLANT DISEASE 381

from a hyphal weft. The fertile branches give rise to chains of
spores every alternate cell of which atrophies. The outer row of
sporophores and potential spores remains sterile to form the
peridium. When young the acium is immersed and globular,
at maturity erumpent and forms an open cup. These spores
germinate by a tube capable upon proper hosts of stomatal infec-
tion and following this of producing the uredinium.

Urediniospores are produced throughout the season even through
the winter under proper climatic conditions. They also remain
viable for weeks ' 174 and doubtless serve hibernation purposes. °°

Teliospores arise later in the season in the uredinia or in
separate telia. Unicellular teliospores, mesospores, are oc-
casionally seen. Teliospores germinate best after normal out-
door hibernation, producing the typical 4-celled promycelium,
long sterigmata and solitary basidiospores. If under water the
usual promycelium becomes abnormal and resembles a germ
tube.16” 175

The ecial stage may not occur under certain climatic conditions,
and the uredinia alone perpetuate the fungus.”*! 25% 25% 306 Jt
therefore follows that eradication of the barberry as was at-
tempted by legislative enactment in 1660 in Europe and in 1728
and 1755 in Connecticut and Massachusetts 7° does not extermi-
nate the rust 2°4 (see also *),

Basidiospores were shown by De Bary, 1 confirmed by Ward 7%
and Eriksson, to be incapable of infecting wheat leaves. Suf-
ficient such attempts have, however, not been made on young
tissue.

Jaczewski 2% succeeded in securing germination of pycniospores
but the resulting mycelium soon died and infection was not at-
tained. The same author holds that eciospores may remain
viable about a month, the urediniospores a much shorter time.

. Still hibernation by urediniospores is possible where climatic rela-
tions allow the formation of new uredinia during the winter.

P. rubigo-vera (D. C.) Wint.!% 171 25% 306

1(=.. asperifolium, Pers). Spots large, generally circular, dis-
colored, generally crowded. Peridia flat, broad, with torn white
edges. Spores subglobose, verrucose, orange-yellow, 20-25 yu.

II. Uredinia oblong or linear, scattered, yellow, pulverulent.

382 THE FUNGI WHICH CAUSE PLANT DISEASE

Spores mostly round or ovate, echinulate, with three or four germ
pores, yellow, 20-30 x 17-24 yu.

III. Telia small, oval, or linear, black, covered by epidermis,
surrounded by a thick bed of brown paraphyses. Spores ob-
long or elongate, cuneiform, slightly constricted, the lower cell
generally attenuated, apex thickened, truncate or often obliquely
conical. Spores smooth, brown, variable in size, 40-60 x 15-20 uy.
Pedicels short.

Hetercecious; O and I on Boraginacez.

II and III on rye. The teliospores germinate as soon as mature.

Fic. 275.—P. rubigo-vera, section of uredinium.
ter Bolley.

P. triticina Erik. is the most common and widely distributed
of all rusts of the United States and is a serious wheat pest in
India.” It ordinarily shows only the uredinial stage. The telio-
spores germinate the following spring after a resting period.

Coextensive with wheat culture. Epidemics are frequent.

Bolley ® ” 11 (see also *) has shown it capable of hibernation by
urediniospores and by live winter mycelium and it has further been
shown that the spores themselves can survive freezing in ice. The
zcial stage can be entirely omitted.

This species is combined with P. triticina by Carleton 7! and
treated as two races. The name P. dispersa is also used to
cover the same two species. P. rubigo-vera tritici on wheat and
P. rubigo-vera secalis on rye.

THE FUNGI WHICH CAUSE PLANT DISEASE 383

The ecial stage of the former of these is not known. Its uredinia
survive the severest winters even so far north as the Dakotas.

P. coronata Cda.1® 248 306

I (=. rhamni). Peridia often on very large orange swellings,
causing great distortions on the leaves and peduncles, cylindrical,
with whitish torn edges. Spores subglobose, very finely verrucose,
orange-yellow, 15-25 x 12-18 pn.

II. Uredinia orange, pulverulent, elongated or linear, often con-
fluent. Spores globose or ovate, with three or four germ pores,
echinulate, orange-yellow, 20-28 x 15-20 p.

III. Telia persistent, black, linear, often confluent, long
covered by the epidermis. Spores subcylindrical or cuneiform,
attenuated below, constriction slight or absent, apex truncate,

Fic. 276.—P. coronata, various teliospore forms. After Bolley.

somewhat thickened, with six or seven curved blunt processes,
brown, 40-60 x 12-20 ». Pedicels short, thick.

Hetercecious; I, on Rhamnus frangula.

II and III on various grasses but not on oats.

From this form as earlier understood Klebahn has separated
P. coronifera Kleb. on evidence derived from inoculations, and
made the latter to include these forms with the ecial stage on
Rhamnus cathartica and the uredinial and telial stages on Avena,
Lolium, Festuca, Holchus, Alopecurus and Glyceria. P. coronifera
has been still further divided by Eriksson into eight biologic forms
and P. coronata into three such forms.”

P. glumarum (Schm.) Er. & Hu.? * is widely distributed on
wheat, rye, barley and a few other grasses in India and Europe
but is not known in America.*® Its ecia are not known. By
some this is regarded as a race of P. rubigo-vera. Both
uredinia and teliospores have been reported in the pericarp of
grains.1®

384 THE FUNGI WHICH CAUSE PLANT DISEASE

P. simplex (Korn.) Er. & He.

I. Unknown.

II and III on barley in Europe and seemingly of recent intro-
duction into the United States.

One of the least important of the grain rusts. Mesospores are
common.

P. sorghi Schw.”°

I (=. oxalidis). Peridia hypophyllous, rarely amphigenous,
crowded, concentric, epispore smooth, 24-28 yu.

II. Uredinia amphigenous, numerous, often confluent; spores
globose to ovate, 23-30 x 22-26 mm., slightly verrucose.

Fic. 277.—Puccinia sorghi. After Scribner.

III. Telia amphigenous, black. Spores ovate-oblong or clavate-
obtuse, constricted. Epispore thick, 28-45 x 12-17 yu, smooth,
pedicel long, 5 y, persistent.

Hetercecious. O and I on Oxalis. II and III on Zea. Of little
economic importance.

The relation of the ecial stage was demonstrated by Arthur; 2
it is believed, however, that hibernation is largely by the uredinio-
spores.

P. purpurea C. Amphigenous, spot purplish, sori irregular,
dark-brown.

II. Urediniospores ovate, 35 x 25-30 u, smooth, brown.

III. Teliospores elongate, ovate, brown, long-pedicellate, 40-45
: fos uw. On Sorghum in Southern United States and West

ndies.

THE FUNGI WHICH CAUSE PLANT DISEASE 385

P. phlei-pratensis E. & H.348-261, 303-305

I. Adcia probably on Berberis, but rarely formed.

II. Uredinia 1-2 mm. long on leaves and stems, confluent in
lines 10 mm. or more long, yellow-brown; spores oblong, pyriform,
spiny, 18-27 x 15-19 w. Mycelium perennial.

III. Telia in leaves, sheaths and stems, 2-5 mm. long or
more, confluent, narrow, dark-brown to black, open or partly

Fic. 278.—P. malvacearum. After Holway.

closed. Spores fusiform or club-shaped, medially constricted,
chestnut-brown, apically thickened, 38-42 x 14-16 u.

II and III on timothy grass.

This species is closely related to P. graminis and probably a deri-
vate from it, but it does not seem capable of infecting the bar-
berry under ordinary conditions.*6 28

Inoculation experiments with timothy rust at Washington, D.C.,
show that it can be transferred easily to various grasses. Similar
results have been obtained by Eriksson in Europe. It is not a
well fixed species and by using bridging hosts it can be made to

386 THE FUNGI WHICH CAUSE PLANT DISEASE

transfer to various cereals which it will not attack directly. That
such transfers take place in nature to some extent is probable.*%

P. poarum Niess occurs on bluegrass.

P, malvacearum Mont.?6?765

III. Telia grayish-brown, compact, round, pulvinate, elon-
gate on the stems, scattered, seldom confluent, pale reddish-
brown. Spores fusiform, attenuated at both extremities, apex
sometimes rounded, constriction slight or absent, apical thickening
slight, smooth, yellow-brown, 35-75 x 15-25 u. Pedicels firm,
long, sometimes measuring 120 yu.

A lepto-puccinia on three species of Althea, seven of Malva, two
of Malope; particularly serious on the hollyhock. A native of
Chili, it was first known as a pest in Australia; soon afterward in
Europe. It seems to have entered the United States sometime
prior to 1886 and is now almost universal. The teliospores ger-
minate immediately in suitable environment, mainly from the
apical cell, or may remain alive over winter and originate the
spring infection. The mycelium also hibernates in young leaves.
Mesospores are common. 3 to 4-celled teliospores are also met.

P. heterogena Lag. is also described on
hollyhock from*? South America.

P. chrysanthemi Roze.7*288

II. Uredinia chocolate-brown, single or in
circular groups, hypophyllous, rarely epiphy!l-
lous. Spores spherical to pyriform. ‘Mem-
brane spiny and with three germ pores, 17-27 x
24-32 wu.

Ill. Telia dark-brown hypophyllous. Telio-
spores rarely in uredinia, dark, obtuse, apex
thickened, membrane thick, finely spiny, 20-
25 x 35-43 p. Pedicel 1-114 times the spore
length. .

Fic. 279.—P. helianthi, On cultivated Chrysanthemum. Occasion-
acl ate ally urediniospores like the other uredinio-
spores in all other respects but 2-celled are

found; a habit unique with this rust. In many places uredinio-
spores may be produced continuously and teliospores be but rarely
seen, thus in America only urediniospores have been found. It was

THE FUNGI WHICH CAUSE PLANT DISEASE 387

first seen in America in 1896 (Mass.) and soon spread over the
country. Numerous inoculation trials go to show that it is inde-
pendent of the other rusts common on nearly related Composite.”

P. arenaria Wint.*!

III. Telia compact, pulvinate, roundish, scattered, often cir-
cinate. Spores broadly fusiform or pyriform, summits pointed or
rounded, often thickened, base rounded or attenuated, slightly
constricted, smooth, pale yellowish-brown, 30-50 x 10-20 uz.
Pedicels hyaline, colorless, as long as the spores.

A lepto-puccinia common on Dianthus.

P. helianthi Schw.

O. Pycnia clustered.

I. Aécia in orbicular spots; peridial margins pale, torn; spores
orange, rarely whitish.

II. Uredinia minute, round, chestnut-brown, spores globose to
ovate, 22-26 x 17-22 y», minutely spiny.

III. Telia round, dark-brown to black; spores rounded at base,
slightly constricted, 38-50 x 20-27 uy, smooth; pedicel hyaline,
equal to or longer than the spores.

Auteecious on numerous species of Helianthus, probably divis-
ible into numerous biologic forms. Imported from “America to
Europe. .

Arthur ® used fifteen species of Helianthus on which to sow the
teliospores of Puccinia helianthi produced on three species. The
results are given in table I on page 388.

In the course of three years’ work with this species sixty sowings
were made.

“Looking over the table it will be seen that each set of spores
grew upon the species of host from which derived, but not upon
the other two species, except that spores from H. letiflorus sown
on H. mollis gave a tardy showing of pycnia, without further
development. Also each set of spores grew luxuriantly upon H. an-
nuus, and each made a feeble growth upon H. tomentosus, but on
all other species they either failed to infect or made a feeble growth,
with the single exception that spores from H. letiflorus grew well
on H. scaberrimus.”’ P. Helianthi thus affords an example of a
single species having many races, for which H. annuus acts as a
bridging host.

388 THE FUNGI WHICH CAUSE PLANT DISEASE

TaBLe I
RESULTS OF INOCULATIONS OF HELIANTHUS RUST *

Teliospores taken from
H. mollis 4H. grosse- H. leti-

serratus florus
1. H. annuus + + +
2. H. decapetalus a co) a
3. H. divaricatus a a —
4. H. grosse-serratus fr) a ft)
5. H. hirsutus — te) (0)
6. H. kellermani 0 a _—
7. H. letiflorus to) ts) +
8. H. maximiliani oO re) a
9. H. mollis + o _—
10. H. occidentalis _— 0 _
11. H. orgyalis ° te) te)
12. H. scaberrimus 0 oO +
13. H. strumosus — te) to)
14. H. tomentosus —_— _ _
15. H. tuberosus re) 0 (e)
+ Abundant infection. — Infection, but slow growth and few or no

zcia formed. o No infection. a Not sown.

P. violee (Schum) D. C.?°

J. AKcia on the leaves in circular concave patches, often caus-
ing much distortion on the stems, flat with white torn edges.
Spores subglobose, finely verrucose, orange-yellow, 16-24 x 10-18 u.

II. Uredinia brown, small, roundish, scattered, soon naked.
Spores roundish or elliptical, brown, echinulate, 20-26 u in diameter.

III. Telia black, roundish, small, pulverulent. Spores ellip-
tical or oblong, slightly attenuated at the base, with an apical
thickening, constriction almost absent, brown, 20-35 x 15-20 u.
Pedicels long, deciduous.

An autcecious eu-type on many species of Viola, throughout the
world. Of little economic import.

P. convallarie-digraphidis (Soph.) Kleb. is hetercecious;

I on Convallaria majalis. III on Phalaris.

* Adapted from Arthur.

THE FUNGI WHICH CAUSE PLANT DISEASE 389

P. gentiane Strauss is a eu-puccinia on many species of cul-
tivated gentians. P. gladioli Cast occurs on gladiolus. P. gran-
ularis Kalc. & Cke. is on cultivated Pelargoniums in France; 2”
P. tulipe Schr. on tulips; P. scilla Lk. on Scilla; P. schroeteri
Pass. on Narcissus in Europe. P. pazschkei Diet. is a lepto-
puccinia on cultivated saxifrages in Europe. P. horiana Hen.

aE we
280.—P. dianthi. After Holway.

Fic.

is destructive on Chrysanthemums in Japan.” P. iridis (D. C.)
Duby, a hemi-puccinia, is found on many species of Iris.
P. canne Hen. in its uredinial stage is destructive to Cannas
in the West Indies. P. persistens Plow, is hetercecious. I on
Thalictrum. II and III on Agropyron. P. asteris Duby. is a
very common lepto-puccinia on various asters. P. anemones-
virginiane Schw. is a lepto-puccinia common on anemone.

Key to Uredinales Imperfecti (p. 335)

Spores catenulate

Peridium absent................- ,.... 1. Caoma, p. 390.
Peridium present
Toothed, body cup-shaped. .......... 2. Acidium, p. 390.
Fimbriate, body elongate........... . 3. Restelia, p. 391.
Trregularly split..................-. 4. Peridermium, p. 390.

Spores not catenulate.................4- 5. Uredo, p. 392.

390 THE FUNGI WHICH CAUSS PLANT DISEASE

ZEcidium Persoon (p. 389)

Spores surrounded by a cup-shaped peridium; produced catenu-
late in basipetal series. Germination as in Uredo.

The species are very numerous and belong in the main to Puc-
cinia and Uromyces. Most of the forms of economic interest are
found under these genera. A few others of occasional economic
bearing whose telial stage has not yet been recognized are given
below.

A. brassicze Mont. on Brassica is perhaps identical with Puccinia
isiace. See p. 378. A. tuberculatum E. & K.?!! is reported as
destructive on the poppy mallow. A. pelargonii Thiim. occurs
on geraniums;?” A. otogense Lindsay on Clematis.2” A. cin-
namomi Rac. is serious on the cinnamon tree in Java.

Czoma Link (p. 389)

Sori without a peridium, accompanied by pycnia, with or with-
out paraphyses, produced in chains. Germination as in Uredo.

The forms are mostly stages of Melampsora, Phragmidium or
their kin. Those of economic interest are found under Gymno-
conia and Melampsora.

Peridermium Léviellé (p. 389)

Pyenia truncate-conic.

Peridia caulicolous or foliicolous, erumpent, saccate to tubular,
lacerate-dehiscent, spores catenulate or at maturity appearing
solitary, globose to elliptic or oblong, polyhedral by pressure,
-yellowish-brown. Epispore always verrucose-reticulate.

The ecial stages of Coleosporium, Cronartium, Pucciniastrum,
Melampsorella and Chrysomyxa.

The peridia usually extend conspicuously above the host sur-
face, and rupture irregularly by weathering.

All of the species grow on the Conifers, most of them on Pinus
on both leaves, branches and bark. On the leaves the xcia are
much of the type shown in Fig. 256. When on the woody parts
great distortion may be caused by the perennial fungus and much
injury result to the wood (see Cronartium quercus, p. 352).

The mycelium may live intercellularly in rind, bast and wood

THE FUNGI WHICH CAUSE PLANT DISEASE 391

of pine and continues to extend for years causing swellings of
twigs. Pycnia are either subcuticular or subepidermal and the
pycniospores often issue in a sweetish liquid. ®cia occur as
wrinkled sacs emerging from the bark of the swollen places and
bear spores perennially.

A key to some thirty species is given by Arthur & Kern.

So far as it relates to the distribution of the Peridermiums to
their telial genera it is as follows:

Key to Species or Peridermium

Pycnia subcuticular

Alicia cylindrical.............. 20000 0es Pucciniastrum.
Alicia tongue-shaped...........00eeee Melampsorella, Melamp-
soridium.
Pycnia subepidermal

4écial peridia one cell thick
On. Pinusi:: 360 seesesna cea saeeed Coleosporium.
On Picea respi cscs ie ais se al Melampsoropsis.
On ADIOS oils ost tee dates Tanererrione doe Uredinopsis.

Pycnia subcorticular

Atcial peridia more than one cell thick... Cronartium.

ge:

Such forms as are of economic interest and of which the telial
stage is known are discussed under Coleosporium, Cronartium,
Melampsorella, Melampsoropsis and Pucciniastrum.

Several other forms are found on pine, spruce and Tsuga.

Reestelia Rebentisch (p. 389)

QO. Pycnia spherical or cup-
formed.

I. Acia with strongly de-
veloped thick-walled _ peri-
dium, flask-shaped or cylin- Fic. 281.—R. pyrata, cups showing peridial
dric; spores globose, 1-celled, celle... Alter Kang.
brown to yellow, catenulate, with several evident germ pores.

The forms are the xcial stages of Gymnosporangiums and
occur mostly on Rosaceous hosts. The economic forms will be
found under Gymnosporangium.

392 THE FUNGI WHICH CAUSE PLANT DISEASE

Uredo Persoon (p. 389)

Spores produced singly on the terminal ends of mycelial hyphe.
Germination by a germ-tube which does not produce basidio-

Fic. 282.—Various basidia of
the lower basidiomycetes,
1, auricularias; 2, tremellas
with longitudinal divisions;
3, dacryomycetes with un-
divided forked basidium.

spores, but enters the host-plant through
the stomata.

These forms are in the main discussed
under their telial genera.

U. orchidis Wint. and U. satyrii Mass.
are in the leaves of cultivated orchids.
U. tropzoli Desm. is found on Tropzolum;
U. arachidis Lag. the peanut; **> U. auran-
tiaca Mont. on Oncidium.™ U. au-
tumnalis Diet. on Chrysanthemums in
Japan *! and U. kuhnii (Kr.) Nak. on
sugar cane in Java.

The Auriculariales (p. 323)

Mycelium septate, forming a gelatinous,
irregular and expanded or capitate sporo-
carp; hymenium variable, densely beset
with basidia, on each segment of which is
borne a long sterigma, with its single
spore.

The Auriculariales are mostly sapro-
phytic and of little economic importance.

They embrace some fifty species in two families and are chiefly
of interest on account of the form of their basidia Fig. 282, which
shows relationship both to the Ustilaginales and to the orders to

follow.

Key to Famiues or Auriculariales
Hymenium gymnocarpous. .............. 1. Auriculariacee, p. 392.

Hymenium angiocarpous. .

ie cipee Syee ced a SB 2. Pilacracee.

Auriculariaceze

Key To Trises or GENERA oF Auriculariacere
Sporocarp arising from a ton-like base of

mycelial threads. ....

ene ree I. Stypinellee.

THE FUNGI WHICH CAUSE PLANT DISEASE 393

Basidia free on the end of the hyphe

_ without saccate cell............... 1. Stypinella, p. 393.

Basidia subtended by a saccate cell. .... 2. Saccoblastia.
Sporocarps crustaceous.................. II. Platygleee.
Sporocarps gelatinous, auriform or cap-

Shaped s ec vsa vee gente csc emevvewiwees III. Auriculariez, p. 393.

In tribe III, Auriculariex, there is a single genus, Auricularia.

Cap more or less cup-shaped or ear-like, jelly-like but firm when
wet, horny when dry, the hymenium often veined or folded, but
without teeth. The name refers to the cup-like form.

A. auricula-judiz (L.) Schr. is a very common saprophyte which
is occasionally parasitic on elder, elm, and mulberry in Europe.

In tribe I, few cases of parasitism of any importance are reported.

Stypinella mompa (Tan.) Lin. is found on the roots of mulberry
in Japan.

Eubasidii (p. 299)

The Eubasidii represent the higher development of the basidia-
fungi and contain the majority of the species. The basidia,
the typical club-shaped undivided stalks, bear usually four,
sometimes two, six, or eight unicellular spores on a like num-
ber of sterigmata and are mostly arranged in hymenia. There
is great diversity in the form and size of the sporophore from
an almost unorganized mycelial microscopic weft to the large
complex structures of the toad stools and puff balls. Conidia
and chlamydospores while occasionally present are much less
common than in the preceding groups or orders.

The cells of the sporophore in many forms investigated are
binucleate;** in other forms they are multinucleate.

The origin of the binucleate condition often antedates the for-
mation of the sporophore and may occur far back in the mycelium,
perhaps as far back as the germinating basidiospore itself. 3
In the basidial layer, however, even of those forms with multi-
nucleate vegetative cells, the nuclei are reduced to two so that
the general statement is permissible that in the hymenial layer -
of the Basidiomycetes the cells are binucleate. From such cells
two nuclei wander into the basidium primordium where they
fuse to one, reducing this cell to a uninucleate condition. This

394 THE FUNGI WHICH CAUSE PLANT DISEASE

nucleus by two mitoses gives rise to four nuclei which wander
through the sterigmata into the spores and constitute the four

basidiospore nuclei.
The significance of this phenomenon of fusion in the basidium

followed by division, which is wide spread and apparently the

Q

=

= Ta
ESR

Lars
ot ARETE

/

es ies | a

Fic. 283.—Stages in the development of the basidium (Agaricus); original
binucleate condition, followed (E-F) by fusion, and subsequent mitosis N-R,
resulting in four spore nuclei. After Wager.

dominant typical phenomenon among the Basidiomycetes includ-
ing both high forms, Agarics,*” and low forms, Dacryomycetes,**
the Uredinales 17% 18 18% 313 315 and even the Gasteromycetes
(Maire),*° is much debated. By some it is regarded as a very
much modified type of fertilization, a view to which support is
lent by the fact that in some of these fungi, perhaps all, the
nuclei multiply by a process of conjugate division. Thus the two
nuclei found in the young basidium, although belonging to the
same cell may in ancestry be very distantly related.

THE FUNGI WHICH CAUSE PLANT DISEASE 395

Key To Orpers or Eubasidii

Gelatinous fungi with forked basidia. ..... 1. Dacryomycetales.
Basidia clavate, undivided
Hymenium without stroma, parasites,
basidia free, strict............... 2. Exobasidiales, p. 396.
Stroma usually well developed, fleshy,
coriaceous, leathery or woody
Spores arising from basidia which form
a distinct membranous hymenium
which is naked at maturity, and
frequently covers the surface of
gills, pores or spines (Hymenomy-
COUES) sees cic pee temas eae 3. Agaricales, p. 398.
Spores arising from basidia enclosed in a
definite peridium (Gasteromycetes.)
Spores borne in a more or less deli-
quescent gleba which is at first
enclosed in a peridium, but is at
maturity elevated on stipe..... 4. Phallales, p. 462.
Spores remaining within the peridium
until maturity
Basidia united into a hymenium
which lines the walls of irreg-
ular cavities
Hymenial cavities remaining
together in the peridium,
their boundaries mostly
disappearing at maturity
Fleshy until the maturity of
the spores, capillitium
NONE). .cescancecy waxes 5. Hymenogastrales.
Fleshy when young, at matu-
rity filled with dust-like
spore-masses mixed with
capillitium (puff balls) .. 6. Lycoperdales, p. 464.
Hymenial cavities separating at
maturity from the cup-like
peridium (bird-nest fungi). 7. Nidulariales.
Basidia uniformly distributed
through the peridium or
forming skein-like masses... 8. Sclerodermatales.

396 THE FUNGI WHICH CAUSE PLANT DISEASE

The Dacryomycetales include forms with a gelatinous sporo-
phore. They are mostly small, inconspicuous saprophytes, common
on decaying wood, leaves, etc. The Hymenogastrales are puff-ball
forms, and are very numerous and of very diverse structure. None
have been reported as parasitic. The Nidulariales is a small order
comprising the curious bird-nest fungi, all saprophytes. The
Sclerodermatales are thick-skinned puff balls, mostly subter-
ranean, and not known to be parasitic.

Exobasidiales (p. 395)

Strictly parasitic, the mycelium penetrating the host and usually
causing marked hypertrophy; hymenium unaccompanied by fleshy
sporocarp, consisting only of the closely-crowded, clavate basidia
which break through the epidermis of the host.

The basidia bear four, rarely five or six sterigmata and spores.
The spores are mostly curved. Conidia are also found in some
species. The basidiospores germinate with a germ tube which pro-
duces fine sterigmata and secondary spores capable of budding.
The hymenial cells are binucleate, the two nuclei of the basidial cell
fusing into one basidium-nucleus. This divides mitotically giv-
ing rise to the spore nuclei.

This order among the basidia fungi is analogous to the Exoas-
cales among the ascus fungi. There are two genera and some
twenty-five species.

Key to Genera oF Exobasidiales.

Basidia 6-spored; not gall producers....... 1. Microstroma, p. 396.
Basidia 4-spored; producing galls......... 2. Exobasidium, p. 396.

Microstroma Niessl. contains only three species of which
M. album (Desm.) Sace. is on oak;
M. juglandis (Ber.) Sacc. on Juglans and Hicoria.

Exobasidium Woronin

Mycelium penetrating the host and causing distinct hyper-
trophy, hymenium subcuticular, erumpent, basidia 4-spored,
spores elongate.

There are some twenty species, mostly on members of the

THE FUNGI WHICH CAUSE PLANT DISEASE 397

Ericacee. Cultural work and studies in infection are needed be-
fore species can be properly delimited.”

E. vaccinii (Fcl.) Wor. occurs on Vaccinium vitis idea, forming
large blisters on the leaves,
rarely on petioles and stems,
discoloration red or purple.
The fungus appears as a /
white bloom on the under - ff
surface of the leaf; spores y
narrowly fusiform, 5-8 x
1-2 yp.

Richards *® who studied
E. vaccinii and E. an-
dromedz from inoculations
concludes:

“Aside from the form of
the distortion, E. vaccinii
and E. andromede cannot
well be distinguished. The
former can produce the same
form of distortion on both
Gaylussacia and Andromeda
and the latter has been made
to produce a similar growth
on Andromeda. Micro-
scopically these forms do
not differ. The natural Fic. 284.—Exobasidium andromede# on An-
conclusion is that these two dromeda, showing host cells, mycelium,

A cae basidia and spores. After Richards.
species of Exobasidium are
one and the same and the form producing large bag-like dis-
tortions on Andromeda should be considered a form of E. vac-
cinii.”’

E. oxycocci Rost causes greater hypertrophy than E. vac-
cinii, distorting young twigs and leaves; spores 14-17 x 30 u;
smaller conidia often present. The mycelium infests the leaves
and stems of the cranberry.“ Morphologically the species agrees
closely with E. vaccinii. Infection experiments are needed.

E. vexans Mas “ causes a serious disease on tea. E. andromede

398 THE FUNGI WHICH CAUSE PLANT DISEASE

Pk., E. rhododendri Cram., E. japonicum shirai and E. peckii
Hal. are reported on Rhododendron and Andromeda;

E. azalee Pk. and several other species on various Rhododen-
drons; E. vitis Prill. was noted in France on the grape; *

E. lauri (Borg) Geyl. is on Laurus.

E. cinnamomi Petch on cinnamon in Ceylon.

Agaricales (p. 395) » * 1% 14. 48, 5

This is a very large order of over eleven thousand species.

The mycelium grows to long distances over or through the sup-
porting nutrient me-
dium, often forming
conspicuous long-lived
are m Yesistant rhizomorphic
strands or sheets, some-
times developing sclero-
tia or again appearing
as a mere floccose weft.
4 The basidia bear four
, eee simple spores, in rare
4 cases two, six or eight.
Other forms of conidia
are found in some spe-
cies and chlamydospores

moe ad

scat may be borne either ex-

ternally on the sporo-

MR phore, in the hymenium,
eG

Fic. 285.—An agaric (Amanita) sporophore show- mside of the ais
aoe ae
Kher bok m Ne Bee * lowest forms the basidia

arise directly from the
mycelium without the formation of any definite sporophore but
in most species the sporophore is highly complex, consisting of
large, stalked or sessile, pseudoparenchymatous structures (toad-
stools, mushroom, etc.) on special surfaces of which, the hy-
menium, Fig. 286, lies; covering gills or spines or lining pits or
pores.

The general relation of the basidia to the hymenium and the

THE FUNGI WHICH CAUSE PLANT DISEASE 399

sporophore is shown in Figs. 285,

286. Families are delimited

by the character of the sporophore, distribution of the hymenial

surfaces, presence of cystidia, size
and color of spores, and other more
minor points.

In germination the spore pro-

duces a germ tube which develops
directly into a mycelium. In many

species the young mycelium is :

conidia-bearing.

Cytologically the group conforms |

to the general description given on
pages 393, 394.

The Agaricales are chiefly of in-
terest to pathologists as wood fungi
though in a comparatively few in-
stances they are found on herbs.
Upon wood they may do harm.
First, as root parasites, in which
case death may follow through in-
terference with absorption or an-
chorage. Second, as causes of
heart rots leading to weakness and
eventual overthrow of the tree.
Third, as parasites of sap wood,

cambium or bark leading to death S~#-—0

of a part of the host and often its
complete loss.

In many instances the fungus
draws its subsistence from host

ipaddh} Yah ob

Y ay oF 4 id 0
4 f | 3 3 x
oH A i aes: ¢
i 4 MLS
SIRE CY

Oe

Fic. 286.—Cross section of the gill
showing basidia, sterigmata and
spores, also a cystidium stretch-
ing from one gill to the next.
After Buller. :

cells not actually alive and hence strictly speaking they are
saprophytes. Nevertheless, since their ultimate effect upon the
tree is to cause disease or death, from the practical viewpoint
these fungi are pathogenic. Many species, moreover, can start
their career on a host plant as saprophytes and after attaining a
stage of vigorous vegetative growth become truly parasitic. In
most instances they are wound parasites, which cannot gain ac-
cess to the inner portions of the host through uninjured tissue

THE FUNGI WHICH CAUSE PLANT DISEASE

400

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THE FUNGI WHICH CAUSE PLANT DISEASE

401

but must make entrance through some wound, as those due to

hail, wind, snow, insects, men and other animals,
etc., which exposes the inner bark, cambium, sap
wood or heart wood without its natural outer
protecting tissues.

Within the tissues the mycelium may cause the
disappearance of substances,** e. g., Fomes ig-
niarius consumes the tannin, or the mycelium
may secrete enzymes which penetrate the host to
long distances. These may dissolve first one com-
ponent of the cell, e. g., the lignin, next the
most lignified residue, the middle lamella, re-
sulting in dissolution of the tissue. In other cases
the parts of the cell walls other than the middle
lamella are first affected and soon shrink resulting
in cracks. Fig. 289. Some fungi cause character-
istic color changes particularly in those cell walls
which are rich in carbon. Parasitism in this
group is old since good examples of agarics

Fic. 288.— Tra-

cheid of pine
decomposed by
Trametes pini.
The primary
wall dissolved
as far as aa;
in the lower
part the sec-
ondary and ter-
tiary layers are
only of cellu-
lose; c, myce-
lium making
holes at d and
e. After Har-

tig.

growing on wood are found as early as in the Tertiary

period.

These fungi spread to new hosts by spores borne in various

Fic. 289.—Pine

tracheid acted
upon by Poly-
porus | schwei-
nitzii. The
cellulose has
been extracted
leaving the
walls chiefly
lignin. Drying
has caused
cracks. After
Hartig.

ways; by insects (Trametes radiciperda) animals,
wind (Polyporus pinicola) etc., or in a purely
vegetative manner by the mycelium which in the
form of rhizomorphs (Armillaria mellea) travels
through the ground to considerable distances.**°
An excellent summary of the early history of our
knowledge of wood destroying fungi is given by
Buller.” **°

The number of species of Agaricales which af-
fect live plants in the ways mentioned above is
very great but in many instances research in this
field has not yet revealed the true relation existing
‘between the fungi and the woody plants upon
which they are found growing; whether they
occur as parasites or as saprophytes; whether

aitually injurious or not. The species given below are mainly

402 THE FUNGI WHICH CAUSE PLANT DISEASE

regarded as actually injurious. If more questionable cases were
to be included the number would be increased several fold.

Key To Famiuies or Agaricales

Basidia loosely aggregated on a mold-like
or arachnoid base, formed from loose
floccose hyphe. ..............-..-.. 1. Hypochnacee, p. 402.
Basidia closely aggregated, forming a com-
pact layer
Hymenium smooth
Sporocarp effused, resupinate or rarely
pileate, usually not fleshy. ....... 2. Thelephoracee, p. 405.
Sporocarp clavate, the upper portion
only sporogenous, usually fleshy.. 3. Clavariacez, p. 412.
-Hymenium variously folded or pitted
Hymenium with teeth, tubercles or
tooth-like plates which are sporo-
BCNOUS. ss access seaeeeeeees 4. Hydnacee, p. 413.
Hymenium lining pores
Pores not easily separating from the
pileus, which is commonly
leathery, corky or punky...... 5. Polyporacee, p. 416.
Pores readily separating from the
pileus which is fleshy. ......... 6. Boletacee, p. 440.
Hymenium covering the surface of
radiating plates................. 7. Agaricacee, p. 442.

Hypochnaceze

Sporophore poorly developed and often indefinite, of loosely
woven floccose hyphz; the basidia clavate, loosely aggregated
into an ill-defined hymenium.

In the simplicity of the sporogenous structures the members
of the group approach the Hyphomycetes from which they are
separated only by their sporophores which are of the nature of
basidia rather than of ordinary conidiophores.

A small family of some half dozen genera and sixty species.

THE FUNGI WHICH CAUSE PLANT DISEASE 403

Key To Genera or Hypochnacee

Spores colorless, smooth, rarely granular
Basidia with two sterigmata

Basidia circinate.................... 1. Helicobasidium.
Basidia not circinate
Basidia pyriform, beaked. ......... 2. Urobasidium.
Basidia clavate, not beaked........ 3. Matruchotia.
Basidia with 2-4 rarely 6 sterigmata..... 4. Hypochnus, p. 403.
Basidia with numerous sterigmata
Sterigmata small. ............... 5. Aureobasidium, p. 405.
Sterigmata large. ................. 6. Pachysterigma.
Spores colored, mostly spiny. ............ 7. Tomentella.

Hypochnus Ehrenberg.

Floccose or fungoid, rarely thinly fleshy, spreading over the
substratum; basidia clavate; spores colorless, smooth or minutely
granular.

This genus which contains half the species of the family, is

Fic. 290.—H. ochroleucus sporogenous reticulum prior to spore formation.
8 basidia, sterigmata, and spores. After Stevens and Hall.

with difficulty distinguished from Corticium from which it differs
in the character of its hymenium.

H. ochroleucus N. ‘*“* Sporogenous reticulum of a very close,
irregular net work of hyphe variable in thickness; basidia scattered,

404 THE FUNGI WHICH CAUSE PLANT DISEASE

clavate, swollen; sterigmata 4; spores oblong, slightly flattened on
the side adjacent to the companion spores, tapering slightly at
each end, 4.7-5.8 x 10.5-11.6 ». A migratory mycelium is
present, covering twigs and leaves with a brown felty growth;
rhizomorphs white, later buff, about 5.8 yw, septate. Sclerotia
are also found.

The long cottony rhizomorphic strands extend along the twigs,
up the petioles and in places aggregate to form brown sclerotia,

Fic. 291.—Hypochnus,
semi-diagrammatic _ sec-

tion showing develop- Fic. 292.—Mycelium
ment of hymenium and of Hypochnus show-
basidia, with nuclear ing clamp connec-
conditions. After Har- tions. After Har-
per. per.

which are especially abundant near the terminal buds. On the
leaves Stevens and Hall 4» 4 describe a loose network from which
the basidia arise. Fig. 295. The species is found on apple, pear,
lilac, quince, Vibernum and probably other hosts, and is widely
distributed.

H. cucumeris Frank.

Fungus gray or brown; basidia elongate, bearing 4 sterigmata;
spores ovoid hyaline. Reported on cucumbers *” “ in 1883.

H. solani P. & D. is said to be a parasite of potatoes.” It is
probably identical with Corticium vagum solani. See p. 407.

THE FUNGI WHICH CAUSE PLANT DISEASE 405

H. thez Bern. occurs on tea; ® H. filamentosus Pat. on live
leaves of Caryophyllacee and Amaryllidacee in Quito; H. fu-
ciformis (Berk.) McAlp on grasses in Australia. :

An undetermined species of Hypochnus was studied by Eustace®!
as the cause of rot of stored apples. Artificial inoculations proved
its parasitism, though it was unable to make entrance through
sound surfaces.

The spores are hyaline, smooth, usually obovate, 4-5.5 x2.5-3.5 u.

Aureobasidium Viala & Boyer ® (p. 403)

The fungus body consists of delicate, floccose, more or less
webby masses of much-branched, septate, golden hyphe; basidia
with numerous sterigmata; spores cylindric.

A single species, A. vitis, V. & B., occurs on grape roots in
France and Italy®* 22

Thelephoracee (p. 402)

Sporocarp leathery or membranous, (rarely fleshy, corky or
punky) resupinate or pileate, simple or compound; hymenophore
smooth, warty or wrinkled; basidia numerous, interspersed with
spine-like cystidia.

This is a very large family, but of its eleven hundred species
only a few are parasites.

Key To Genera OF Thelephoracee

Hymenophore without cystidia
Hymenophore entirely resupinate
Spore membrane colorless
Contents colorless
Spores sessile
Basidia with 2 sterigmata. ..
Basidia with 4 sterigmata....
Basidia without sterigmata. .
Spores stalked.....:.........
Contents colored.............--
Spore membrane colored
Hymenophore soon gelatinous.... 6. Aldridgea.
Hymenophore fleshy-leathery.... 7. Coniophora.
Hymenophore partially free, shelving
Context of several layers. ......... 8. Stereum, p. 409.

. Cerocorticium.

. Corticium, p. 406.

. Protocoronospora, p. 409.
. Michenera.

. Aleurodiscus.

oP Wd eS

406

Context of only one layer
Hymenophore leathery

Hymenium not ribbed
Hymenium almost smooth or
with warts
Basidia continuous....... 9
Basidia septate... ....... 10
Hymenophore smooth....... 11
Hymenium with ribs
Ribs becoming warty....... 12
Ribs with warty spines...... 13
Hymenophore not leathery
Hymenophore gelatinous-fleshy 14.

Hymenophore membranous, rare-
ly fleshy or fleshy-leathery
Hymenium exterior to the
hymenophore. ...........
Hymenium inside the hy-
menophore
Hymenophores mostly soli-
tary ;
Hymenophore sessile or
laterally stipitate.....
Hymenophore centrally
attached
Hymenophores

Hymenophore with cystidia
Cystidia of a single cell
Cystidia unbranched
Hymenophore of a single layer
Hymenophore resupinate......
Hymenophore laterally short-

Hymenophore of several layers...
Cystidia stellate-branched.........
Cystidia of several cells.............

16.

17.

THE FUNGI WHICH CAUSE PLANT DISEASE

. Thelephora, p. 410.
. Septobasidium, p. 411.
. Hypolyssus.

. Cladoderris.
. Beccariella.

Phlebophora.

. Craterellus.

Cyphella.

Discocyphella.

. Solenia.

. Peniophora.

. Skepperia.

. Hymenochete, p. 411.
. Asterostroma.

. Bonia.

Corticium Persoon (p. 405)

Hymenophore homogeneous in structure, membranous, leathery
or fleshy, almost waxy, rarely approaching gelatinous; hymenium

THE FUNGI WHICH CAUSE PLANT DISEASE 407

arising immediately from the mycelium, smooth or minutely
warty; basidia clavate, with four sterigmata; spores small, globose
or ellipsoid, with a smooth colorless membrane.

A genus of some two hundred fifty species, mostly wood inhab-
iting.

One species possesses a mycelium which has long been known
in its sterile form as a Rhizoctonia.

Corticium vagum solani Burt. °45 324

Hymenophore, white when sporing, poorly developed, of loosely
interwoven hyphe; basidia short, cylindric or oblong; spores some-

Fic. 294.—C. vagum-solani,
Fie. 293.—C. vagum solani Rhizoc- basidia, sterigmata and
tonia stage. After Duggar. spores. After Rolfs.

what elliptic, often irregular in outline, 9-15 x 6-13 u.

‘Sterile mycelium(=Rhizoctonia solani=Rhizoctonia violacea) 54
turning yellowish with age, and branching approximately at
right angles; often forming sclerotia-like tufts with short, broad
cells more or less triangular which function as chlamydospores.

Brown to black sclerotial structures, a few millimeters in diam-
eter, consisting of coarse, broad, short-celled hyphe of peculiar
and characteristic branching also occur freely, both in nature and
in culture, Fig. 298. These cells seem capable of functioning as
chlamydospores.

The hymenophore consists of a dark network of hyphe which
changes to grayish-white when sporing. It frequently entirely
surrounds the green stems of the host near the ground. The tips of
the outermost hyphe are sterigmatate. The spores germinate
readily, developing into typical Rhizoctonia mycelium.

The relation which the various Rhizoctonias which have been
described on numerous hosts may bear to the one species under

408 THE FUNGI WHICH CAUSE PLANT DISEASE

discussion is problematic. Much culture and inoculation work is
needed. Some of the various hosts upon which a Rhizoctonia
apparently closely allied to that of Corticium vagum solani have
thus far been found in America are:

Sugar-beet, bean, carrot, cabbage, cotton, lettuce, potato,
radish, sweet potato, pumpkin, watermelon, garden pea, corn,
purslane, Solanum verbascifolium, egg plant, pig-weed, spiny
pig-weed, Heterotheca subaxillaris, Richardia, Crotalaria, Cy-
perus rotundus, Heterotheca lamarckii and Phytolacca decandra,
Pinus sps., **” *4? Picea, Pseudotsuga, carnation and alfalfa.

The sterile mycelium was noted in Europe on potato many years
ago; its existence in America has been known since 1890 (Duggar**).
Its identity with the genus Corticium was demonstrated in 1904
by Rolfs * both by observing the connection between the myce-
lium and the basidia on young potato plants and by culture of
the typical Rhizoctonia stage from the basidiospores. The parasi-
tism of the organism was proved by inoculations made with pure
culture by Rolfs.*®

The sterile mycelium (Rhizoctonia) occurs in two forms on
the potato, a light-colored actively parasitic form usually some-
what deep in the affected tubers and a darker mycelium growing
superficially on the host or over the soil. In artificial culture the
manner of branching is typical, the young branches running
nearly parallel to the main thread and bearing slight constrictions
at their bases. ;

A key to the species in France is given by Bourdot and Gol-
zin, 164

C. letum (Karst.) Bres.

Plant body at first salmon-colored, soon fading to a dirty-white;
context, of hyphe which are nodose, septate, irregular, 4-10 yu,
basidia clavate, 35-50 x 7-12 u; spores oblong ovate, subde-
pressed on one side, hyaline, 10-14 x 6-8 u.

On fig and apple in Louisiana, and in Europe and in the Northern
United States on Alnus, and Corylus. It causes the limb blight
of the fig, ** 1° gaining entrance through dead twigs. While the
fungus is usually a saprophyte, once it gains entrance to the host
it follows down the branch, covering it with its bright salmon-
colored fructification and causing sudden wilting and dying of the

THE FUNGI WHICH CAUSE PLANT DISEASE 409

leaves. The cambium layer is the seat of the disease. The fungus
spreads rapidly but is not a serious pathogen except in rainy periods
in midsummer.

C. javanicum (Hen.) S. & S. causes disease of coffee and tea; ®
C. dendriticum Hen. parasitizes orange stems; *® C. comedens
(Nees) Fr. occurs on oak as a wound parasite; C. zimmermannii
S. & Syd. injures many tropical trees; © C. lilacino-fuscum Berk.
& Curt. occurs on cacao.

C. chrysanthemi Plow. is reported as the cause of death of
cultivated chrysanthemum in England.

Protocoronospora Atkinson & Edgerton (p. 405)

Genus as in Corticium, except for the basidia which bear 4-8
sessile, oblong or elliptic spores.

P. nigricans Atk. & Edg.®! forms narrow elongate spots on vetch
pods, stems and leaves. Spot, oblique on the pods, 2-5 x 1-2 mm.,
at first white or with a purple border, later black; subhymenial
layer subepidermal two or three cell layers thick; basidia clavate,
to subcylindric, 20-30 x 6-8 u; spores sessile, pale-pink in mass,
oblong to subelliptic, hyaline, smooth, granular, continuous, or
l-septate in germination, straight or curved. Found on vetch at
Ithaca, N. Y., associated with Ascochyta.

Stereum Persoon (p. 405)

Hymenophore leathery or woody, persistent, of several layers,
sometimes perennial, laterally or centrally attached; hymenium
smooth.

A genus of about two hundred fifty species chiefly wood in-
habiting, but a few grow in humus.

S. hirsutum (Willd.) Pers.

Hymenophore leathery, firm, expanded, wrinkled, hairy, yellow-
ish; the hymenium yellowish, smooth.

It causes a rot of oak in which the wood appears white-spotted
in cross section.

S. quercinum Potter,® is found on oak in Europe.

S. frustulosum (Pers.) Fries, though sometimes found on living
trees, is confined to dead wood. It causes a speckled rot of oak

wood.” Fig. 295.

410 THE FUNGI WHICH CAUSE PLANT DISEASE

S. purpureum Pers.

Hymenophore expanded, leathery, arched, grayish-white; hy-
menium smooth, purple.

This species is constantly associated with an English and Cana-
dian disease of drupaceous and pomaceous trees, manifest by a

Fic. 295.—Oak timber rotted by Stereum frustulosum. The
lighter colored, irregular, small bodies are sporophores. After
von Schrenk and Spaulding.

silvering of the leaves, death of branches and finally of the tree.
The causal agency of the fungus has not been fully established.®
Cosmopolitan in distribution.
S. rugosum Fr. parasitizes the cherry laurel.

Thelephora Ehrenberg (p. 406)

Hymenophore leathery, context similar, variable in form,
sessile or pileate, even or more commonly plicate; hymenium con-
fined to the lower surface or extending all over the hymeno-
phore, smooth or uneven, sometimes warty; basidia numerous,
clavate; spores elongate, membrane often dull brown, and granular.

THE FUNGI WHICH CAUSE PLANT DISEASE 411

T. laciniata Pers. injures various trees by its leathery incrustations.

T. galactina Fr.

Resupinate, broadly effused, encrusted, smooth, milky in color.
The root rot on oak is in type much like that caused by Armillaria

Fic. 296.—Telephora laciniata. After Clements.

mellea. It also causes a root rot of apple trees throughout the
Central States.®4

Hymenochetze noxia Berk. is a practically omnivorous fungus
attacking hevea, cacao, tea, dadap, castilloa, Caravonica cotton,
bread fruit, camphor, throughout the eastern tropics.

Septobasidium Pat. (p. 406)
As Thelephora but with septate basidia.

412 THE FUNGI WHICH CAUSE PLANT DISEASE

S. pedicillata (Schw.) Pat.®

Resupinate, effused, byssoid, subcompact, light cinnamon-
yellow to white, hymenium smooth.

On oak, palmetto, tupelo, apple, etc. Cosmopolitan.

Clavariacez (p. 402)

Hymenophore fleshy, leathery, cartilaginous or waxy, cylin-
dric-clavate, simple or branched often quite large and conspicuous
hymenium with cystidia; basidia clavate, with 1 to 4 sterigmata;
spores elliptic or fusiform, hyaline.

There are about five hundred species. One genus only is para-
sitic.

Key To Genera or Clavariaceze

Hymenophore small, simple
Basidia with 1 or 2 sterigmata
Spores colored. .................0. .. 1. Baumanniella.
Spores hyaline =
Hymenophore expanded above into a
cap, basidia with 1 sterigma...." 2. Gloeocephala.
Hymenophore clavate, basidia with

2 sterigmata. ............2.-. 3. Pistillaria.
Basidia with 4 sterigmata ;
Hymenophore clavate or filiform.... 4. Typhula, p. 412.
Hymenophore capitate, hollow..... 5. Physalacria.

Hymenophore usually large, branched,
rarely simple
Hymenophore mostly round, branches
never leaf-like
Hymenophore fleshy. ............... 6. Clavaria.
“Hymenophore not fleshy

Hymenophore cartilaginous orhorny. 7. Pterula.
Hymenophore leathery and hairy... 8. Lachnocladium.
Hymenophore leaf-like................ 9. Sparassis.

Typhula graminum Karst. has been reported as injuring wheat.

Hymenophore fleshy or waxy, delicate, simple orrarely branched,
filiform or cylindric, clavate; spores colorless. Sometimes forming
sclerotia. Fig. 297.

T. variabilis Riess. is regarded as a parasite of beets.

THE FUNGI WHICH CAUSE

Hydnacee (p. 402)

Sporophore variable in texture, cu-
ticular, leathery, corky, felty, fleshy or
woody; free and stipitate, shelving
or resupinate; the hymenium warty,
thorny, spiny or with tooth-like
plates; basidia usually 4-spored, rarely
1-spored.

Over five hundred species, mostly
very limited in their geographical
distribution, and chiefly epixylous,
although some are humus-loving.

PLANT DISEASE 413

he *s
aires?

Fic. 297.—Typhula variabilis,
M, habit sketch; n, basidium
and spores. After Winter.

Key ro GENERA oF Hydnacere

Sporophore annual
Hymenium without a subiculum. ......
Hymenium with a subiculum.
Hymenium with folds or wrinkles
Crest of the folds entire...........

Hymenium with granules or warts
Granules penicillate, multifid
Hymenophore fleshy. ...........
Hymenophore firm, not fleshy. . ..
Granules simple
Hymenium porose, reticulate,
granular. ...............00-
Hymenium with obtuse cylindric
WAPtB ys eto theese sess oes
Hymenium with globose hollowed

Hymenium with more or less subulate
teeth or spines
Pileus clavaria-like. ...............
Pileus not clavaria-like
Teeth free, mostly fleshy
Teeth rounded.

1. Mucronella.

2. Phiebia.
3. Lopharia.

4. Kneiffiella.
5. Odontia.

6. Asterodon.
7. Radulum.

8. Grandinia.

9. Hericium,

414 THE FUNGI WHICH CAUSE PLANT DISEASE

Spores hyaline.............. 10. Hydnum, p. 414.
Spores colored.............- 11. Pheodon.
Teeth lammeliform.......... 12. Sistotrema.
Teeth connected at base, coriaceous
Cystidia none. ............... 13. Irpex, p. 415.
Cystidia present.............. 14. Hydnochete.
Sporophore perennial, punky or woody
Upper surface smooth, or suleate. ..... 15. Echinodontium, p. 415.
Upper surface zonate.................. 16. Steccherinum, p. 416.

Hydnoum Linnzus

Sporophore cuticular, leathery, corky, woody or fleshy, variable
in form, resupinate; pileus, shelving, or bushy branched; hymenium
beset with pointed spines; basidia with 4 sterigmata; spores hya-
line.

The species of this genus, between two hundred fifty and three
hundred, are mostly sapro-
phytes but a few are true
parasites on woody plants.

H. erinaceus Bul.”

Cap 5-30 cm. wide, white,
then yellowish or somewhat
brownish, the branches form-
ing a dense head covered
with teeth, fleshy; stem
short and stout, 2-8 cm. long
and thick, or entirely lack-
ing; teeth 3-10 cm. long,

: slender, densely crowded;
Tic. 298.—Fruiting body of Hydnum erina-

ceus in a hollow log. After von Schrenk SDOres globose, clear, 5-6 H.
and Spaulding. The name refers to the ap-

pearance of the head.

It is the cause of a white rot on many deciduous trees, chiefly
oaks. The rotted wood is soft and mushy. Numerous large holes
filled with masses of light yellowish fluffy mycelium occur in the
heart-wood. Sporophores are often absent on the rotted tree.

H. septentrionale Fr.

Sporophores in bracket-like clusters, up to 20-30 cm. wide by

THE FUNGI WHICH CAUSE PLANT DISEASE 415

50-80 cm. long, creamy white in color, texture at first fleshy, be-
coming more fibrous; pileus often 3 cm. thick, upper surface al-
most plain, slightly scaly, all pilei united behind, teeth slender,
often 12 mm. long.

On sugar maple, beech, etc., causing rot of the heart-wood.

H. diversidens Fr.” causes white rot of oak and beech in Europe.

H. schiedermayeri Heuff,® injures apple trees in Europe.

Irpex Fries (p. 414)

Sporophore shelving or resupinate, hymenium on the lower side,
from the first toothed; teeth firm, subcoriaceous, acute, continuous

vn bel
Fie. 299.—I. flavus. H, habit sketch. After Hennings.

with the pileus, arranged in rows or reticulately, basally widened
and lamellate or even favoid; basidia 4-spored.

I. fusco-violaceus (Schrad) Fr. is a wound parasite on pine in
Europe.

I. flavus Klotsch is injurious to the Para rubber, cloves and
coffee; I. destruens to tea.

I. paradoxus (Schrad) Fr., according to Glazan,” causes timber
rot.

Echinodontium Ellis & Everhart (p. 414)

Similar to Hydnum but differing in perennial habit; pileus,
smooth, woody; cystidia bearing spines.

E. tinctorium E. & E.”" *** is the only species.
Spines brown, 1 cm. long, 114-2 mm. broad; cystidia subconic,

reddish-brown, 20-30 x 6-7 yu.

416 THE FUNGI WHICH CAUSE PLANT DISEASE

On living trunks of Tsuga, Pseudotsuga ™ and Abies in north-
western North America.

Steccherinum S. F. Gray (p. 414)

Perennial, pileate, sulcate, zonate, radiately subrugose; teeth
wide, irregular.

S. ballouii Banker is the single economic species.

Campanulate to subdimidiate, more or less intricate, sessile,
decurrent to pendent, 14 x 1-5 em. laterally connate up to 10 cm.;
surface velutinous when young, often licheniferous at base, dark
olive-brown, drying gray-brown in older parts and seal-brown
in younger; margin obtuse, seal brown; substance thin, 1-2 mm.,
of two layers, the upper harder, somewhat brittle, dark brown,
lower softer and lighter colored; hymenium colliculose, golden-
yellow, fading to buff or cream; teeth variable, subterete to diform,
confluent, papalloid to elongate, usually obtuse, tips brownish,
1-5 x 0.5-1 mm. irregularly distributed; spores hyaline broadly
elliptic to subglobose, 7-7.2 x 5.5-6.5 p.

On Chamecyparis in New Jersey.”2 According to Ballou”
this fungus is devastating the forests of swamp cedar in New Jersey.
As it grows only in the tops of the tree and dies with the host, the
dead sporophores soon disappearing, it is a species not easily
observed.

Polyporacez (402)

Sporophore annual or perennial; context fleshy, tough, corky
or woody; hymenium poroid or lamelloid, fleshy to woody, rarely
gelatinous.

The sporophores are sometimes fleshy, even edible but they are
more commonly hard and woody, occurring as bracket forms,
Fig. 310, on tree trunks.

Key to Genera oF Polyporacesze
Pores reduced to shallow pits separated by

narrow ridges, folds or reticulations... 1. Meruliew, p. 418.
Pores well developed, variable in size and
POPM soi. BNE: as cls he enban aan bee II. Polyporee.

Sporophore, at least in part gelatinous

THE FUNGI WHICH CAUSE PLANT DISEASE 417

Sporophore more or less gelatinous
throughout. . ...............08.
Sporophore leathery above, the pores
gelatinous. . ..............00005
Sporophore leathery, corky or punky,
never gelatinous. Pores minute and
rounded or large and angular
Sporophore resupinate, never shelv-

Sporophore normally pileate, only ac-
cidently resupinate
Pores usually small or medium sized,
and round
Substance of the pileus not con-
tinuing ‘between the pores
Sporophore at first fleshy, then
hardening................
Sporophore from the first

Sporophore from the first more
or less corky or punky,
usually perennial..........

Substance of the pileus continued
between the pores. .........
Pores usually large, hexagonal or
labyrinthiform rarely bounded
by large plates
Pores hexagonal
Stipe lateral; pores elongate. .. .
Sessile; pores regular..........
Pores labyrinthine, or replaced by
plates R
Sporophore sessile
Hymenium labyrinthine, be-
coming irpiciform. ......
Hymenium lamellate, not be-
coming irpiciform.......
Sporophore stipitate, concentri-

1. Laschia.

2. Gleoporus.

3. Poria, p. 418.

4. Polyporus, p. 418.
5. Polystictus, p. 426.

6. Fomes, p. 428.

7. Trametes, p. 437.

8. Favolus, p. 439.
9. Hexagonia.

10. Deedalea, p. 439.
11. Lenzites, p. 439.

12. Cyclomyces.

418 THE FUNGI WHICH CAUSE PLANT DISEASE

Merulius lachrymans of the tribe Meruliez is said to parasitize
violets.°”*

Poria Persoon (p. 417)

Sporophore entirely resupinate, often widely extended, the
base leathery to punky, pores small, rounded, covering almost the
entire surface.

A genus of almost three hundred species.

P. levigata Fr. causes a white rot of the birch.

P. vaporaria (Pers.) Fr. is a wound parasite on coniferous trees "4
especially common on spruce and fir causing a brown rot of the sap
wood.

P. subacida Pers.’ Sporophore effused, determinate; margin
pubescent, white; pores minute, subrotund, 2-6 mm. oblique,
odor subacrid. A common saprophyte on deciduous and conif-
erous trees especially, pine, hemlock, and spruce. Irregular
cavities form within the diseased wood and become lined with a
tough felt of hyphz, yellow on the inner side.

P, hypolaterita Berk. causes a tea disease in Ceylon.”

P. vineta Berk. is reported as causing a rot of Hevea in Ceylon.”

Polyporus (Micheli) Paulet (p. 417)

Sporophore usually annual; simple or compound, rather thick,
fleshy, leathery or corky, stipitate or shelving, pores developing
from the base toward the margin. Grading into Polystictus on
the one hand and approaching Fomes on the other.

There are about five hundred species.

P, obtusus Berk. 7

Pileus somewhat imbricate, large and spongy, at-length indurate,
dimidiate, sessile, often ungulate, 5-7 x 10-15 x 3-5 cm.; surface
spongy-tomentose, hirtose, azonate, smooth, sordid-white to
isabelline or fulvous; margin very thick and rounded, sterile,
entire, concolorous; context spongy-fibrous, white, indurate with
age especially below, 1-2 cm. thick; tubes very long, 2-3 cm.,
white to isabelline within, mouths large, irregular, often sinuous,

1-2 mm. broad, edges thin, fimbriate-dentate to slightly lacerate,
white to isabelline, at length bay and resinous in appearance; spores
globose, smooth, hyaline, 6-8 u; hyphe hyaline, 6 u; cystidia none.

THE FUNGI WHICH CAUSE PLANT DISEASE 419

It causes a heart-rot of living oaks, occurring as a wound parasite
and invading the sap wood when decay is well advanced. It is
also found on black locust.**”

P. sulphureus (Bul.) Fr.° &% 7% 74 79, 80

Hymenophore cespitose-multiplex, 30-60 em. broad ; pileus
cheesy, not becoming rigid, reniform, very broad, more or less
stipitate, 5-15 x 7-20 x
0.5--1 cm.; surface finely
tomentose to glabrous,
rugose, anoderm, sub-
zonate at times, vary-
ing from lemon-yellow
to orange, fading out
with age; margin thin,
fertile, concolorous,
subzonate, finely to-
mentose, undulate,
rarely lobed; context
cheesy, very fragile |% a

4

when dry, yellow when Fic. 300.—Polyporus sulphureus. Scattered fruit
fresh, usually white in bodies on living oak. After Atkinson.

dried specimens, homogenous, 3-7 mm. thick; tubes annual,
2-3 mm. long, sulphur-yellow within; mouths minute, angular,
somewhat irregular, 3-4 to a mm., edges very thin, lacerate,
sulphur-yellow, with color fairly permanent in dried specimens;
spores ovoid, smooth or finely papillate, hyaline, 6-8 x 3-5 uy.

It is common as a cause of red heart-rot of forest and shade
trees, conifers and deciduous, and also does damage in the orchard,
especially on cherry, apple and pear, and im the forest to oak, chest-
nut, poplar, maple, walnut, butternut, alder, locust, ash, pine,
hemlock, larch.

The decayed wood resembles a mass of red-brown charcoal and
is characterized by radial or concentric cracks in which the fungus
forms thin leathery sheets. In dicotyledons the vessels become
filled with the fungus. Round gonidia are often formed within
the wood.

P. squamosus (Huds.) Fr.

Sporophore of immense size, reaching 50 cm. in breadth and 3 cm.

11, 67, 81

420 THE FUNGI WHICH CAUSE PLANT DISEASE

in thickness, usually found in imbricated masses projecting from
the trunks of living trees. Pileus subcircular and umbilicate when
young, soon becoming flabelliform and explanate; surface ochra-
ceous to fulvous, covered with broad, appressed, darker scales

Fic. 301.—Polyporus squamosus. After Clements.

which are very close together in young specimens; margin in-
volute, thin, entire; context fleshy-tough, juicy, milk-white; very
thick, odor strong; tubes decurrent, white or pale yellowish, very
short, mouths large, alveolar, 1 mm. or more in diameter, edges
thin at maturity, toothed at an early age, becoming lacerate:
spores broadly ovoid, smooth, hyaline, 5 x 12 u; stipe excentric
to lateral, obese, reticulate above, clothed at the base with short,

THE FUNGI WHICH CAUSE PLANT DISEASE 421

dark brown or black, velvety tomentum, often reduced, variable
in length.

The mycelium causes white rot of nut, ornamental and fruit
trees, particularly maple, pear, oak, elm, walnut, linden, willow,
ash, birch, chestnut, beech, growing on dead parts of living trees.
The hyphe advance most rapidly along the wood vessels and
often bear clamp connections.

A beautiful biological study has been published by Buller» ®
who states that a single sporophore may produce 11,112,500,000
spores and that “the number produced by a single fungus from a
single tree in the course of a year may, therefore, be some fifty
times the population of the globe.”’

He showed the following enzymes to be present in the sporo-
phore: laccase, tyrosinase, amylase, emulsin, protease, lipase,
rennetase, and coagulase. Pectase, maltase, invertase, trehalase
and cytase were not found; It is evident, however, that the my-
celium in wood produces cytase and possibly hadromase.

P. hispidus Bul.

Pileus thick, compact, fleshy to spongy, dimidiate, sometimes
imbricate, compressed-ungulate, 7-10 x 10-15 x 3-5 cm.; surface
hirsute, ferruginous to fulvous, azonate, smooth; margin obtuse,
velvety; context spongy-corky, somewhat fragile when dry, fer-
ruginous to fulvous, blackening with age, 1-1.5 cm. thick; tubes
slender, about 1 cm. long, ferruginous within, mouths angular,
2-3 to a mm. ferruginous to bay, blackening with age, edges thin,
very fragile, lacerate; spores broadly ovoid, smooth, thick-walled,
deep-ferruginous, 2-guttulate, 5-6 x 7-8 yp.

It is common on all kinds of deciduous trees, often injuring fruit
trees, especially the apple.

P. giganteus (Pers.) Fr. has been reported as injurious to the
oak.

P. glivus Fr. is a common saprophyte on deciduous trees and in
some cases may be parasitic.

P. dryophilus Berk.

Pileus thick, unequal, unguliform, subimbricate, rigid, 7-8 x 10-
14 x 2-3 em.; surface hoary-flavous to ferruginous-fulvous, becom-
ing scabrous and bay with age; margin thick, usually obtuse,
sterile, pallid, entire or undulate: context ferruginous to fulvous,

422 THE FUNGI WHICH CAUSE PLANT DISEASE

zonate, shining, 3-10 mm. thick; tubes slender, concolorous with
the context, about 1 cm. long, mouths regular, angular, 2-3 to a
mm., glistening, whitish-isabelline to dark-fulvous, edges thin,

= |

SS

ae

ie
eS

4, mb

AG "SEE

Bes.
ane

es

@ b- ec @ 6 f 9 +b

Fic. 302.— Decomposition of spruce-timber by Polyporus borealis. a, a
tracheid containing a strong mycelial growth and a brownish yellow fluid
which has originated in a medullary ray; at b and c the mycelium is still
brownish. At d and e the walls have become attenuated and perforated,
the filaments delicate; at f the pits are almost destroyed; at g and h only
fragments of the walls remain.'’’ The various stages in the destruction
of the bordered pits are to be followed from 7 to 7; at 7 the bordered pit
is still intact; at k the walls of the lenticular space have been largely dis-
solved, their inner boundary being marked by a circle; at l one side of
the bordered pit has been entirely dissolved; at m and n one sees a series
of pits which have retained a much-attenuated wall on one side only—
namely, on that which is provided with the closing membrane. In mak-
ing the section a crack has been formed in this wall. Between o andr
both walls of the pits are found to be wholly or partially dissolved, only
at p and q has the thickened portion of the closing membrane been pre-
served; at d the spiral structure of both cell-walls is distinctly recogniz-
able. These walls when united form the common wall of the tracheid; at
t hyph are seen traversing the tracheids horizontally. After Hartig.

entire to toothed; spores subglobose, smooth, deep-ferruginous,
6-7 pu; cystidia scanty and short; hyphe deep-ferruginous.
It causes a disease of oaks.

P. fruticum B. & C. occurs on living twigs of the orange and
oleander in Cuba.

THE FUNGI WHICH CAUSE PLANT DISEASE 423

P. borealis (Wahl.) Fr.°™ 78

Pileus sessile, subimbricate, dimidiate to flabelliform, often
narrowly attached, spongy to corky, very tough, moist and juicy
when fresh, 5-8 x 8-12 x 2-4 cm.; surface uneven, soft and spongy,
hirtose-tomentose, azonate, white to yellowish; margin thin, white,
entire, somewhat discolored on drying:
context fibrous-coriaceous above, fibrous-
woody below, white, 0.5-1.5 cm. thick;
tubes 4-8 mm. long, white to pallid within,
mouths angular, irregular, somewhat
radiately elongate, sinuous at times, 1-2
to a mm., stuffed when young, edges thin,
white to ochraceous, dentate to lacerate;
spores ovoid, smooth, hyaline, 5-6 x 34 un;

Fig. 303.—Polyporus bo-

hyphe 6-7 By cystidia none. realis, hymenium with
On pine, spruce, hemlock, balsam pine, _fimuous pores. After At-

etc., as a wound parasite or as a sapro-
phyte on dead trees producing a white rot. The mycelium ad-
vances longitudinally, radially and tangentially. At certain
stages it is very abundant and forms cords in the channels formed
by the fungous enzyme. Later these cords disappear. The young
mycelium is stout and yellow, later it is more delicate. Dis-
solution of the cells begins at the lumen
and proceeds outward, the middle lamella
persisting last.
P. dryadeus Fr.™
Sporophore very large, sessile, dimidiate,
rarely circular, usually imbricate, applanate
or depressed above, convex below, fleshy to
= spongy-corky, rather fragile when dry, 15-
seek eee Ne eke 30 x 25-65 x 3-5 em.; surface very un-
ee ee After even, azonate, opaque, hoary-isabelline,
anoderm tovery thinly encrusted, sub-
shining and bay; margin thick, pallid, entire to undulate, weep-
ing; context thick, zonate, subglistening, ferruginous-isabelline to
fulvous, 2.5-4 cm. thick; tubes grayish-umbrinous to fulvous
within, 5-15 mm. long, slender, very fragile, mouths whitish when
young, becoming somewhat resinous in appearance and finally

424 THE FUNGI WHICH CAUSE PLANT DISEASE

bay-brown, at first minute, circular, becoming angular, 4 to a
mm., edges thin, fimbriate to lacerate, deeply splitting and
separating with age: spores subglobose, smooth, 9-10 x 7-8 u,
the outer wall hyaline, the inner membrane brown; cystidia 15-
35 x 5-9 yp.

It causes rot of oak wood in America and Europe.

P. amarus Hedg.* ie

Pileus soft and spongy when young, becoming hard and chalky
when old, ungulate, often spuriously stipitate from knot-holes, fre-
quently large, 5-11 x 10-20 x 6-12 cm.; surface pubescent when
young, rimose and chalky when old, at first buff, becoming tan
and often blotched with brown when older; margin obtuse, fre-
quently ‘having an outer band of darker brown, often slightly
furrowed; context creamy-yellow to tan-colored, usually darker in
outer layers when old, 4-8 cm. thick; tubes not stratified, brown
within, cylindric, 0.5-3 cm. in length, shorter next the margin,
mouths circular or slightly irregular, 1-3 to a mm., yellow-green
during growth, turning brown when bruised or old, becoming
lacerate; spores hyaline or slightly tinged with: brown, smooth,
ovoid, 3-4 x 5-8 py, nucleated; cystidia none.

The cause of ‘‘pin rot’”’ or peckiness of incense cedar.

P, schweinitzii Fr.” ?

Pileus spongy, circular, varying to dimidiate or irregular, 15-20
cm. broad, 0.5-2 cm. thick; surface setose-hispid to strigose-
tomentose and scrupose in zones, ochraceous-ferruginous to ful-
vous-castaneous or darker, quite uneven, somewhat sulcate, ob-
scurely zonate; margin yellow, rather thick, sterile: context very
soft and spongy, fragile when dry, sometimes indurate with age,
flavous-ferruginous to fulvous, 0.3-0.7 mm. thick; tubes short,
2-5 mm. long, flavous within, mouths large, irregular, averaging
1 mm. in diameter, edges thin, becoming lacerate, ochraceous-
olivaceous to fuliginous, rose-tinted when young and fresh, quickly
changing to dark-red when bruised: spores ovoid, hyaline 7-8 x 3-4
yw: stipe central to lateral or obsolete, very irregular, tubercular
or very short, resembling the pileus in surface and substance.

On coniferous trees especially spruce, fir, pine, larch, arbor vite,
entering through the root system: and extending up the trunk,
causing heart-rot. The tracheids exhibit spiral cracks and fissures

THE FUNGI WHICH CAUSE PLANT DISEASE 425

due to the shrinking of the walls. Fig. 289. Diseased wood is

yellowish and of cheesy consistency; brittle when dry.
P. betulinus (Bul.) Fr.®” 8
Pileus fleshy to corky, compressed-ungulate, convex above,

After von Schrenk

and Spaulding.

Fic. 305.—A dead yellow birch tree with fruiting body of P. betulinus.

plane below, attached by a short umbo behind, varying to bell-
shaped when hanging from horizontal trunks, 5-30 x 5-20 x 2-5
em.; surface smoky, covered with a thin, separating pellicle,
glabrous, devoid of markings, cracking with age; margin velvety,
concolorous, obtuse, projecting nearly a centimeter beyond the

426 THE FUNGI WHICH CAUSE PLANT DISEASE

hymenium: context fleshy-tough, elastic, homogeneous, 3 cm. thick,
milk-white; tubes 0.5 cm. long, 2-3 to a mm., sodden-white, sepa-
rated from the context by a thin pink layer; mouths very irregular,
dissepiments thicker than the pores, obtuse, entire, crumbling
away in age, leaving the smooth, white context; spores white,
‘cylindrical, curved, 4-5 p» in length. The mycelium penetrates
lignified cell walls entering the living cells and causing death.

On birch it causes a decay of the sap wood similar to that caused
by Fomes fomentarius.

P. adustus (Wild.) Fr. is a common saprophyte of deciduous trees.

Polystictus Fries (p. 417)

Sporophore leathery, usually thin; pores developing from the
center to the circumference of the hymenophore. The thicker
forms are quite close to some species of Polyporus.

About four hundred fifty species.

P, versicolor (L.) Fr.5” ®

Pileus densely imbricate, very thin, sessile, dimidiate, conchate,
2-4 x 3-7 x 0.1-0.2 cm.; surface smooth, velvety, shining, marked
with conspicuous, glabrous zones of various colors, mostly laterice-
ous, bay or black; margin thin, sterile, entire; context thin, mem-
branous, fibrous, white; tubes punctiform, less than 1 mm. long,
white to isabelline within, mouths circular to angular, regular,
even, 4-5 to a mm., edges thick and entire, becoming thin and
dentate, white, glistening, at length opaque-isabelline or slightly
umbrinous: spores allantoid, smooth, hyaline, 4-6 x 1-2 uy;
hyphe 2-6 u; cystidia none.

Von Schrenk regards this as strictly a saprophyte except when
on catalpa, where it causes a heart-rot. It is common on almost
any kind of wood.

Catalpa wood under its action becomes straw-colored and finally
soft and pithy. Both cellulose and lignin are dissolved.

P. sanguineus (L.) Fr. & P. cinnabarinus (Jacq.) Fr. are sapro-
phytes on dead parts of live trees.

P.velutinus (Pers.) Fr. is a common saprophyte which is perhaps
sometimes parasitic.

P. occidentalis Klachb. is recorded as a parasite on Pterocarpus
indicus in the Malay peninsula.®*

THE FUNGI WHICH CAUSE PLANT DISEASE 427

P. pergamenus ['r.””

Pileus exceedingly variable, sessile or affixed by a short tubercle,
dimidiate to flabelliform, broadly or narrowly attached, 2-5 x 2-6
x 0.1-0.3 cm.; surface finely villose-tomentose, smooth, white
or slightly yellowish,
marked with a few nar-
row indistinct laterice-
ous or bay zones; mar-
gin thin, sterile, entire to
lobed; context very thin,
white, fibrous; tubes 1-
3 mm. long, white to dis-
colored within, mouths
angular, somewhat irreg-
ular, 34 to a mm.,
usually becoming irpici-
form at an early stage,
edges acute, dentate, be-
coming lacerate, white to
yellowish or umbrinous: 5 Glements.
spores smooth, hyaline.

It causes a sap wood rot of practically all species of deciduous
trees, often on dead trees, less frequently on living trees which
have been severely injured. In general the rotten wood resembles
that produced by P. versicolor; microscopically it is seen that
the fungus attacks chiefly the lignin.

P. hirsutus Fr.

Pileus confluent-effused, more or less imbricate, sessile, dimi-
diate, applanate, corky-leathery, rather thick, flexible or rigid,
3-5 x 5-8 x 0.3-0.8 em.; surface conspicuously hirsute, isabelline to
cinereous, concentrically furrowed and zoned; margin at length
thin, often fuliginous, sterile, finely strigose-tomentose, entire or
undulate: context white, thin, fibrous, spongy above, 14 mm.
thick; tubes white, 1-2 mm. long, mouths circular to angular,
4 to a mm., quite regular, edges thin, firm, tough, entire, white
to yellowish or umbrinous; spores smooth, hyaline, cylindrical,
slightly curved, 2.5-3 u.

It is a wound parasite of the Mountain Ash.

428 THE FUNGI WHICH CAUSE PLANT DISEASE

Fomes Fries (p. 417)

Sporophore sessile, ungulate or applanate; surface varnished,
encrusted, sulcate, vinose, or anoderm, rarely zonate; context
corky to punky; tubes cylindric, stratiose; spores smooth, hyaline
or brown.

A genus of some three hundred species.

F. igniarius (L.) Gill. 7”

Pileus woody, ungulate, sessile, 6-7 x 8-10 x 5-12 cm.; surface
smooth, encrusted, opaque, velvety to glabrous, ferruginous to

Fic. 307.—Fomes igniarius, from maple. After Atkinson.

fuscous, becoming rimose with age; margin obtuse, sterile, fer-
ruginous to hoary, tomentose; context woody, distinctly zonate,
ferruginous to fulvous, 2-3 cm. thick; tubes evenly stratified,
2-4 mm. long each season, fulvous, whitish-stuffed in age, mouths
circular, minute, 3-4 to a mm., edges obtuse, ferruginous to ful-
vous, hoary when young: spores globose, smooth, hyaline, 6-7 F
spines 10-25 x 5-6 yp.

It is the cause of a white heart-rot, is one of the most widely
distributed forms of wound parasites and occurs on more species
of broad-leaf trees than any other similar fungus. Among its
hosts are beech, oak, apple, peach, willow, aspen, the maples, birch,
butternut, walnut, oak, hickory, alder.

The first sporophores usually appear at the point of initial

THE FUNGI WHICH CAUSE PLANT DISEASE 429

infection. The mycelium grows mainly in the heart wood but it

may gain entrance through the sap wood or encroach upon the

sap wood from the heart wood. Its growth may continue after

the death of the host. In early stages it follows the medullary
¢

Fic. 308.—A dead beech tree with sporophores of F. fomenta-
rius. After von Schrenk and Spaulding.

rays. The completely rotted wood is white to light yellow and in
it the mycelium abounds in the large vessels and the medullary
rays. The walls of the affected wood cells are thin and the middle
lamella is often wholly lacking, due to solution of the lignin.

F. fomentarius (L.) Fr. &

Pileus hard, woody, ungulate, concave below, 7-9 x 8-10 x 3-10
cm.; surface finely tomentose to glabrous, isabelline to avellaneous

430 THE FUNGI WHICH CAUSE PLANT DISEASE

and finally black and shining with age, zonate, sulcate, horny-
encrusted; margin obtuse, velvety, isabelline to fulvous; context
punky, homogeneous, ferruginous to fulvous, conidia-bearing,
3-5 mm. thick; tubes indistinctly. stratified, not separated by lay-
ers of context, 3-5 mm. long each season, avellaneous to umbrinous
within, mouths circular, whitish-stuffed when young, 3-4 to a mm.;
edges obtuse, entire, grayish-white to avellaneous, turning dark
when bruised: spores globose, smooth, very light brown, 3-4 u;
hyphe brown, 7-8 u; cystidia none.

The mycelium kills the cambium and causes a white rot of the
sap wood of deciduous trees, especially beech, birch, elm, maple.
The wholly rotted wood is soft, and spongy, light yellow and
crumbles into its separate fibers.

F. everhartii (E. & G.) ® 8’ (=Pyropolyporus prerimosa).

Pileus woody, dimidiate, ungulate, broadly attached behind,
6-10 x 6-15 x 3-8 cm.; surface glabrous, slightly encrusted, deeply
sulcate, not polished, gray to brownish-black, slightly rimose

in age; margin obtuse, covered with ferruginous tomentum, be-.~ -
coming gray and glabrous: context corky to woody, repeatedly -

zoned, fulvous in dried specimens, 2-3 cm. thick; tubes evenly
stratified, 0.5-1 cm. long each season, fulvous, mouths circular,
4 to a mm., edges rather thin, entire, ferruginous to fulvous,
glistening, the hymenium becoming much cracked in age: spores
globose, smooth, ferruginous, 3-4.5 »; spines abundant, pointed,
larger at the base, 15-25 x 6-10 y.

On black oaks, and walnuts *° causing a rot almost indistin-
guishable from that caused by F. igniarius. The mycelium
often grows into the living sap wood.

F. carneus Nees.” ®

Pileus woody, dimidiate, varying from conchate to ungulate
often imbricate and longitudinally effused, 2-4 x 6-8 x. 0.5-3 cm.;
surface rugose, subfasciate, slightly sulcate, rosy or flesh-colored,
becoming gray or black with age; margin acute, becoming obtuse,
sterile, pallid, often undulate; context floccose-fibrose to corky,
rose-colored, 0.2-2 cm. thick; tubes indistinctly stratose, 1-2 mm.
long each season, mouths circular, 3-4 to a mm., edges obtuse,
ecpetsgiea! spores ellipsoid, smooth, thick-walled, subhyaline,

5x 6 ps.

THE FUNGI WHICH CAUSE PLANT DISEASE 431

On red cedar and arbor vite causing pockets, also on dead
spruce and fir. The cellulose is almost all removed from the
affected cells of the heart wood. The mycelium is scant and when
young is pale and with numerous clamps. It extends horizontally
through the tracheids, giving off lateral branches. None is found
in the sap wood.

F. annosus (Fr.) Cke.”* **> (=Trametes, radiciperda R. Hartig).

Pileus woody, dimidiate, very irregular, conchate to applanate,
10-13 x 5-8 x 0.5-2 cm.; surface at first velvety, rugose, anoderm,
light brown, becoming thinly encrusted, zonate, and finally black
with age; margin pallid, acute, becoming thicker; context soft-
corky to woody, white, 0.3-0.5 cm. thick; tubes unevenly stratified,
2-8 mm. long each season, white, mouths subcircular to irregular,
3-4 to a mm., edges rather thin, entire, firm, white, unchanging:
spores subglobose or ellipsoid, smooth, hyaline, 5-6 x 4-5 u.

On pine, fir and various deciduous trees, described by Hartig*®
as the most dangerous of all conifer parasites. It is not so plentiful
in America as in Europe.

The sporophores appear near or on the roots, between the
bark scales, where the white felted delicate mycelium also occurs.
The spores, carried presumably by rodents, germinate upon the
bark of roots; the mycelium penetrates to the living cortex, forces
its way into the wood and follows up the stem and down the root.
The parenchyma cells are killed and browned; the wood becomes
violet, later brownish-yellow. The hyphz travel in the cell-
lumen and pierce the walls. The lignified parts are dissolved
first, later the middle lamella disappears. Eventually the whole
root system may become involved and the death of the tree result.

F. juniperinus (v. Sch.) 8S. & Sy.¥

Pileus woody, ungulate, 3-5 x 5-8 x 5-7 cm.; surface tomentose,
deeply sulcate, ferruginous to gray, at length rough and grayish-
black; margin obtuse, velvety, melleous or ferruginous to hoary:
context corky to woody, reddish-fulvous, 0.5-1 cm. thick; tubes
indistinctly stratified, 0.5-1 cm. long each season, melleous within,
reddish-fulvous in the older layers, mouths circular to angular,
2-3 to a mm., edges rather thin, entire, even, melleous: spores
reddish-brown, smooth; spines blunt, only slightly projecting.
On red cedar.

432 THE FUNGI WHICH CAUSE PLANT DISEASE

In the holes caused by the fungus in the heart-wood is found
a velvety mass of reddish-yellow mycelium, glistening with color-
less liquid and holding masses of reddish-brown wood fiber. Long
white fibers of cellulose with the lignin removed project into the
cavities from the ends.

Structural change begins soon after the mycelium enters a
celllumen. The primary lamella becomes granular and is dissolved
by a lignin-splitting enzyme, the secondary lamella becomes white
and the cells fall apart.

The mycelium in newly invaded tissue is nearly hyaline and
extends lengthwise. Within the tracheids branches are given off
in all directions.

The sporophore appears after decomposition is considerably
advanced.

F. laracis (Jacq.) Murr.***

Pileus firm, at length fragile, ungulate to cylindical, 3-8 x 5-10
x 4-20 cm.; surface anoderm, powdery, white or slightly yellow-
ish, concentrically sulcate, becoming slightly encrusted, tuberculose
and rimose; margin obtuse, concolorous: context soft, tough, at
length friable, chalk-white or slightly yellowish, very bitter,
with the odor of fresh meal, 1-3 cm. thick; tubes evenly strati-
fied, concolorous, 5-10 mm. long each season, mouths circular to
angular, 3-4 to a mm., edges thin, fragile, white, becoming dis-
colored and lacerate, wearing away with age: spores ovoid, smooth,
hyaline, 4-5 yu; hyphe 5 y; cystidia none.

A wound parasite of the larch, pine and spruce in Europe and
America.

F. ribis (Schw.) Gill.

Pileus tough, corky, becoming rigid, conchate, laterally connate,
3-5 x 5-10 x 0.7-1.5 cm.; surface rough, velvety, anoderm, in-
distinctly zoned, ferruginous to umbrinous, becoming glabrous
and slightly encrusted with age; margin undulate to lobed, fer-
ruginous, furrowed: context punky, fulvous, 3-5 mm. thick;
tubes indistinctly stratified, 1-2 mm. long each season, fulvous,
mouths circular, 5-6 to a mm., edges rather thin, entire, ferruginous
to fulvous, hoary when young: spores globose or subglobose,
pale yellowish-brown, smooth, 3-4 x 3 »; hyphe 2.5 y; cystidia
none.

THE FUNGI WHICH CAUSE PLANT DISEASE 433

This is a wound parasite on the heart wood of sassafras and is
also found on roots and stems of various shrubby plants including
Tose, gooseberry and currant. The fungus fills the large vessels
and tracheids with a brown mycelium and dissolves the entire
wall locally.

F. fulvus (Scop) Gill.

Pileus woody, triquetrous, rarely ungulate, thick and broadly
attached behind, 1-3 x. 5-7 x 3-8 cm.; surface smooth, very
slightly sulcate, velvety, ferruginous, becoming horny and
glabrous and finally nearly black with age; margin subobtuse,
ferruginous, velvety; context woody, fulvous, 1-2 cm. thick;
tubes evenly stratified, 2-3 mm. long each season, fulvous, mouths
circular, 3 to a mm., edges obtuse, entire, ferruginous to fulvous;
spores globose, compressed on one side, hyaline, 5.5-6 x 4.5-5 yu;
spines fulvous, 15-20 x 7-9 u; hyphe 2.5 yp.

On plum, birch and other trees.

The decayed wood is red-brown and crumbles when crushed.

F. fulvus olez Lin.” is injurious on olive in Italy.

F, nigricans Fr. ™ is very similar to F. igniarius from which it
differs chiefly in the black upper surface and the bluish or blackish
hymenial surface of the sporophores. Murrill *! regards it as a
variety of F. igniarius.

As a wound parasite it causes a reddish-brown heart-rot of
deciduous trees, especially of willow, birch, poplar, beech.

F. lucidus (Fr.) Bon. causes a cocoanut root-rot.

F. fraxinophilus (Pk.) Sacc.®

Pileus woody, subtriangular, compressed-ungulate, usually
decurrent, 5-10 x 6-12 x 2-4 cm.; surface white, pulverulent or
finely tomentose, concentrically sulcate, becoming gray or black
and rimose with age; margin tumid, white or yellowish, velvety to
the touch; context: corky to woody, zonate, isabelline, 0.5-1 cm.
thick; tubes evenly but indistinctly stratified, 2-4 mm. long each
season, white when young, concolorous with the context in the
older layers, mouths white, subcircular, 2 to a mm., edges obtuse;
spores broadly ellipsoid, smooth, hyaline, thin-walled, 6-7 x 7-8
u; hyphe light yellowish-brown, 10-12 y; cystidia none.

It causes a heart-rot of trunk and branches of species of ash.

The starch in the host cells is lost early by diastatic action in

434 THE FUNGI WHICH CAUSE PLANT DISEASE

advance of the fungus, the nearest hyphe of which may be several
millimeters distant, and is replaced by a decomposition product.
The mycelium advances through the medullary rays and spreads
through spring and summer bands, abstracting the lignin; the
middle lamella dissolves and the cells fall apart. Completely
rotted wood is straw-colored, very soft, non-resistant. The young
hyphe are very fine and require an immersion less for observation.
Clamp connections are frequent. The sporophore appears after
the destruction of the wood is considerably advanced.

F. hartigii All. is very similar to, if not identical with,
F. igniarius.

It produces a white rot of firs and spruces. The mycelium is
yellowish with numerous branches which may fill the cavities of
the bordered pits of the tracheids. The middle lamella is even-
tually dissolved, later the inner walls.

F. robinie (Murr.) S. & Sy. ™ %

A large fungus with dark rimose surface and tawny hymenium.
Pileus hard, woody, dimidiate, ungulate to applanate, 5-25 x 5-50
x 2-12 cm.; surface velvety, smooth, soon becoming very rimose
and roughened, fulvous to purplish-black, at length dull-black,
deeply and broadly concentrically sulcate; margin rounded,
velvety, fulvous; context hard, woody, concentrically banded,
1-3 em. thick, fulvous; tubes stratose, 0.15-0.5 cm. long, 50 a
mm., fulvous, mouths subcircular, edges entire, equaling the
tubes in thickness: spores subglobose, smooth, thin-walled, fer-
Tuginous, copious, 4-5 yw; cystidia none.

On black locust causing heart-rot, arising from wound infection
of living trees. The very hard wood becomes a soft, yellow to
brown mass, spongy when wet. The decay extends out in radical
lines from the center, along the large medullary rays, killing the
cambium and bark on reaching them. The lignin is first dissolved,
later the cellulose.

The fungus ceases growth on the death of its host.

F. marmoratus Berk. (=F. fasciatus [Sw.] Cooke.)

Pileus hard, woody, dimidiate, applanate to ungulate, convex
above, 7-10 x 8-15 x 2-6 cm.; surface finely tomentose, at length
glabrous, concentrically sulcate, at first mole-colored, changing
to umbrinous, and finally avellaneous with black fasciations;

THE FUNGI WHICH CAUSE PLANT DISEASE 435

margin acute to obtuse, isabelline, sterile, undulate or entire;
context punky, thin, ferruginous to fulvous, zonate, 3-5 mm.
thick, tubes indistinctly stratified, 5-10 mm. long each season,
avellaneous within, mouths circular, minute, 4-5 to a mm. edges
obtuse avellaneous to umbrinous, becoming darker when bruised:
spores subglobose, smooth, light brown, 5-7 »; hyphe brown, 4-6y;
cystidia none.

On water oak and orange in Florida, especially abundant on
the former.

F. sessilis (Murr.) Sacc.

A variable fungus with wrinkled varnished cap and acute margin,
found on decaying deciduous trees. Pileus corky to woody, dimidi-
ate, sessile or stipitate, imbricate or connate at times, conchate
to fan-shaped, thickest behind, thin at the margin, 5-15 x 7-25
x 1-3 cm.; surface glabrous,
laccate, shining, radiate-
rugose, concentrically sul-
cate, yellow to reddish-
chestnut, at length opaque,
dark-brown usually marked
near the margin with alter-
nating bay and tawny
zones; margin usually very
thin and acute, often curved
downward, often undulate,
rarely becoming truncate,
white, at length concolorous:
context soft-corky or woody,
radiate-fibrous, concentri-
cally banded, ochraceous-

fulvous; ‘tubes 0.52 cm.

: es mm "Fic. 309.—F. pinicola growing on dead trunk
long, 3-5 to a -, brown of western hemlock. After von Schrenk.

within, mouths circular or

angular, white or grayish-brown, edges thin, entire: spores ovoid,
obtuse at the summit, attenuate and truncate at the base, verru-
cose, yellowish-brown, 9-11 x 6-8 y; stipe laterally attached,
usually ascending, irregularly cylindrical, 14 x 0.5-1.5 em., re-
sembling the pileus in color, surface and substance, often obsolete.

436 THE FUNGI WHICH CAUSE PLANT DISEASE

It occurs on oak and maple * as a wound parasite, destroying
bark and cambium. This and related species are usually
saprophytic.

F. pinicola (Fr.) Cke.”

Pileus corky to woody, ungulate, 8-15 x 12-40 x 6-10 cm.;
surface glabrous, sulcate, reddish-brown to gray or black, often
resinous; margin at first acute to tumid, pallid, becoming yellowish
or reddish-chestnut: context woody, pallid, 0.5-1 cm. thick; tubes
distinctly stratified, 3-5 mm. long each season, white to isabelline,

Fic. 310.—Fomes applanatus. After Clements.

mouths circular, 3-5 to a mm., edges obtuse, white to cream-colored;
spores ovoid, smooth, hyaline, 6 u; hyphe 8 uy; cystidia none. é

It occurs on conifers; pine, hemlock, spruce, balsam, larch, etc.,
more rarely on beech, birch and maple, as a wound parasite of
the heart wood. The sporophores are often absent until after
death of the host. The tracheids bear many holes. The wood
carbonizes, the cellulose is destroyed and sheets of mycelium form,
particularly within the space occupied by the medullary rays and
in tangential crevices.” °° Fig. 309.

F. applanatus (Pers.) Wallr.

Pileus hard, woody, dimidiate, applanate, 6-15 x 8-30 x 14 cm.;
surface milk-white to gray or umbrinous, glabrous, concentrically
sulcate, encrusted, fasciate with obscure lines, condia-bearing,

THE FUNGI WHICH CAUSE PLANT DISEASE 437

usually brownish during the growing season from the covering of
conidia; margin obtuse, broadly sterile, white or slightly cremeous,
entire to undulate: context corky, usually rather hard, zonate,
fulvous to bay, 5-10. mm. thick, thinner with age; tubes very
evenly stratified, separated by thin layers of context, 5-10 mm.
long each season, avellaneous to umbrinous within, mouths circular,
5 to a mm., whitish-stuffed when young, edges obtuse, entire,
white or slightly yellowish to umbrinous, quickly changing color
when bruised: spores ovoid, smooth or very slightly roughened,
pale yellowish-brown, truncate at the base, 7-8 x 5-6 pu.

It is described by Heald “ as the cause of rot of both heart and
sap wood of living cotton-wood trees. The invaded medullary
rays first lose their starch by digestion. Next the lignin is dis-
solved, then the cellulose.

Von Schrenk regards this fungus as a saprophyte since it grows
usually only on outer sap wood that is dead and so far as he ob-
served, it does not cause a true disease.

F. ulmarius Fr. is injurious to elm.

F. semitosus Berk. causes root rot of Hevea in India.

F. australis Fr. is a wound parasite on Acacia in Ceylon.*”

Trametes Fries (p. 417)

Sporophore annual, rarely perennial, sessile; context homo-
geneous, coriaceous to corky, extending between the tubes, which
are circular or irregular.

There are about one hundred forty-five species:

T. pini (Thore) Fr.5® 7 78 7° :

Pileus hard, woody, typically ungulate, conchate or effused-
reflexed in varieties, often imbricate, 5-8 x 7-12 x 5-8 em., smaller
in varieties; surface very rough, deeply sulcate, tomentose, tawny-
brown, becoming rimose and almost black with age; margin rounded
or acute, tomentose, ferruginous to tawny-cinnamon, entire,
sterile in large specimens: context soft-corky to indurate, homo-
geneous, ferruginous, 5-10 mm. thick, thinner in small specimens;
tubes stratified, white to avellaneous within, becoming ferrugi-
nous at maturity and in the older layers, 5 mm. long each season,
much shorter in thin specimens, mouths irregular, circular or
dedaleoid, often radially elongate, averaging 1 to a mm., edges

438 THE FUNGI WHICH CAUSE PLANT DISEASE

ferruginous to grayish-umbrinous, glistening when young, rather
thin, entire; spores subglobose, smooth, hyaline at maturity,
becoming brownish with age, 5-6 x 3-4 u; spines abundant, short,
25-35 x 4-6 yu.

It occurs on pine, spruce, larch, hemlock, and fir as a wound
parasite of the heart wood; it is also on willow in Europe and
America.

The spores are wind-borne and, lodging on unprotected sur-
faces, develop a mycelium which grows both up and down, spread-
ing most rapidly in a longitudinal direction, or horizontally follow-
ing an annual ring. The fungous enzyme first dissolves the lignin
leaving the individual tracheids free and of nearly pure cellulose.
The cellulose is later dissolved, resulting in holes in the wood.
It is found on most of the conifers of the United States as a sapro-
phyte. The wood becomes white-spotted. In late stages of decay
the entire wood is full of small holes which are lined with a white
fungous felt.

T. ribinophila Murr. is perhaps a parasite on the black locust.

T. thee Zimm. cause a root-
rot of tea in India.”

T. suaveolens (L.) Fr.

Pileus large, subimbricate,
dimidiate, sessile, convex above,
plane or concave below, 4-6 x
5-12 x 1-3 cm.; surface smooth,
anoderm, azonate, finely villose-
tomentose to nearly glabrous,
white to pale-isabelline; margin
thick, sterile, entire: context
white, punky-corky, 1-2 cm.
thick, very fragrant when fresh,

Fic. 311.—Favolus europzeus. with the odor of anise; tubes 5-

aster Leyes: 15 mm. long, white within,

mouths circular, 2 to a mm., edges at first very thick, white, entire,

becoming thinner and often blackish with age: spores oblong-ovoid,

subsinuate, smooth, hyaline, 8-9 x 3-5 yw; hyphe 7 4y; cystidia
none.

On willow.

THE FUNGI WHICH CAUSE PLANT DISEASE 439

Favolus Fries (p. 417)

Sporophore leathery, fleshy, or coriaceous, laterally stipitate;
hymenium with large elongated pores which may even become
lamellate, Fig. 311.

A genus of some seventy species.

F. europzus Fr. is a European parasite of fruit and nut trees; it
is also common in America.

Dedalea Persoon (p. 417)

Hymenophore epixylous, usually large and annual, sessile,
applanate to ungulate; surface anoderm, glabrous, often zonate:
context white, wood-colored or brown, rigid, woody, tough or
punky: hymenium normally labyrinthiform, but varying to lamel-
late and porose in some species: spores smooth, hyaline.

About seventy-six species. Fig. 312.

D. quercina (L.) Pers.

Pileus corky, rigid, dimidiate, sessile, imbricate, applanate,
convex below, triangular in section, 6-12 x 9-20 x 2-4 em.; surface
isabelline-avellaneous to cinereous or smoky-black with age,
slightly sulcate, zonate at times, tuberculose to colliculose in the
older portions; margin usually thin, pallid, glabrous; context
isabelline, soft-corky, homogeneous, 5-7 mm. thick; tubes laby-
rinthiform, becoming nearly lamellate with age in some specimens,
1-2 cm. long, 1-2 mm. broad, chalk-white or discolored within,
edges obtuse, entire, ochraceous to avellaneous.

Common on oak and chestnut,**” often on living trees but
growing only on the dead wood.

Lenzites Fries (p. 417)

Hymenophore small, annual, epixylous, sessile, conchate;
surface anoderm, usually zonate and tomentose: context white or
brown, coriaceous, flexible; hymenium lamellate, the radiating
gill-like dissepiments connected transversely at times, especially
when young: spores smooth, hyaline. Fig. 313.

About seventy-five species.

440 THE FUNGI WHICH CAUSE PLANT DISEASE

L. abietina (Bul.) Fr. occurs on firs. L. sepiaria (Wulf.) Fr.
has been reported as a parasite on pine, spruce, etc., but recent
work of Spaulding ® shows it to be merely a saprophyte. L. cor-
rugata Klot, L. vialis Pk. and L. betulina (L.) Fr. are common

Fic. 312.—Dedalea quercina on oak. After von Schrenk and Spaulding.

saprophytes on deciduous trees; perhaps also parasitic; L. varie-
gata Fr. on beech and poplar.

Boletacee (p. 402)

Sporophores fleshy, capitate, centrally or laterally stipitate,
rarely actually sessile; hymenium on the under surface only, of
tubes which separate readily from the pileus and are united to
each other or only closely approximated.

A family of less than three hundred species.

Key To GENERA OF Boletaceze

Pores adnate to each other................ I. Boletinez.
Pores separate tubes. ................... II. Fistulinee.
Sporophore more or less fleshy......... 1. Fistulina, p. 441.
Sporophore leathery
Tubes with a central papilla........ 2. Theleporus.

Tubes without papille.............. 3. Porothelium.

THE FUNGI WHICH CAUSE PLANT DISEASE 441

Fistulina Buller (p. 440)

Sporophore fleshy, laterally short-stipitate, hymenial sur-
face at first granular, then each granule becoming a tube; these
‘are approximate but not united; spores brown in mass. F ig. 314.

A genus of a half dozen species.

Fic. 313.—Lenzites betulina. After Clements.

F. hepatica (Scha.) Fr.

Cap 8-20 cm. wide, bright-red or red-brown, liver-shaped to
shelf-like, more or less lobed, smooth, more or less sticky when
wet; flesh containing reddish fibers; stem short, lateral and almost
wanting, or sometimes long excentric; tubes pale to yellowish or

442 THE FUNGI WHICH CAUSE PLANT DISEASE

pinkish; spores yellowish to pinkish, ellipsoid, 5-7 x 3-4 u.
It is found on oak and chestnut.
Agaricacee (p. 402)”

Sporophore usually fleshy, rarely coriaceous or leathery, stip-
itate or shelving; stipe variable in development, lateral or central,

Fig. 314.—Fistulina hepatica. After Clements.

annulate or not, the entire young sporophore often volvate at
first; hymenium lamellate, the lamelle usually free, rarely anas-
tomosing, sometimes dichotomous, rarely reduced to ridges or

slight folds.
A family of over twelve hundred species.

Key to Trises or Agaricacese

Hymenium with the lamelle ridge or fold- ~~
like, imperfectly developed. .......... I. Cantharellex, p. 443.
Ilymenium with normally developed gills
Lamelle sometimes anastomosing, and
forming meshes. .................. II. Paxilles.
Lamelle not anastomosing
Lamelle and often the cap deliquescent
(in Montagnites withering,). ..... III. Coprinee.
Lamelle not deliquescent
Lamelle thick and fleshy, becoming
WAXY. euvissndtiiets mance eta IV. Hygrophoree.

THE FUNGI WHICH CAUSE PLANT DISEASE

Lamellz not fleshy or waxy
Substance of the pileus of two
kinds of hyphe, one thick,
tubular and in bundles, the
other thin, single and fre-
quently lactiferous.......... V. Lactarier.
Substance of the pileus of only onc
kind of hyphz
Sporophore at maturity leathery
or corky, persistent, rarely
fleshy
Lamelle at maturity split

lengthwise. ............ VI. Schizophyllee, p. 444.

Lamelle at maturity not

splitting............... VII. Merasmiee, p. 445.

Sporophore at maturity fleshy,

finally putrescent......... VIII. Agaricee, p. 448.

Cantharellez (p. 442)

This tribe is characterized by its low ridge or fold-like lamelle.
The hymenial characters indicate an approach to the Thelephora-

cee.

Key ro Genera or Cantharelles

Hymenium on the upper side of the pileus. 1. Rimbachia.
Hymenium on the under side of the pileus.
Hymenium with thin veins

Veins anastomosing................. 2. Campanella.
Veins not anastomosing.. ........... 3. Arrhenia.
Hymenium with thick folds
Substance of the pileus leathery,
TOUS siaaieders Ces tote vs ae 4. Trogia, p. 444.
Substance of the pileus thin, soft-
leathery
Sporophore sessile, at first saucer-
shaped: . 2x essence es eye nes 5. Leptopus.
Sporophore laterally stalked, fan-
shaped. ............-.2000005 6. Leptoglossum.

Substance of the pileus fleshy........ 7. Cantharellus.

444 THE FUNGI WHICH CAUSE PLANT DISEASE

Trogia Fries (p. 443)

Cap thin, leathery, or membranous, persistent, sessile, irreg-
ular; hymenium of branched
folds, the branches chiefly mar-
ginal.
There are some seven species.
T. faginea. (Schr.) v. Sch.
Sporophore 1-2 cm. broad,
; beaker-formed or irregular mar-
Fic. lnrtinn ents gined; yellow or orange without,
rarely whitish, with fine hairs;
ribs concolorous, dichotomous; spores cylindric, 4 x 1-1.5 u,
smooth, colorless.
It injures birch, beech, hazel, etc.

Schizophylleez (p. 443)

Sporophore, leathery, persistent, the cleft gills with recurved
margins. A group of but four genera and less than a score of
species.

Key To GENERA OF Schizophyllez

Sporophore leathery, sessile. ............. 1. Schizophyllum, p. 444.
Sporophore fleshy or membranous, stipitate
Stipe central

Cap thin, membranous. ............. 2. Rhacophyllus.
Cap fleshyay are es See ee 4. @demansiella.
Dtipevlateralse scree eek ate dee uet ers 3. Pterophyllus.

Schizophyllum Fries

Cap woolly, upturned, sessile, epixylous; gills cleft, the mar-
gins recoiled; texture leathery.

About twelve species. Fig. 316.

S. alneum (L.) Schr.

Cap 14 em. wide, white or gray-woolly, upturned, attached
excentrically, irregularly saucer-shaped: stem lacking; gills grayish
to purplish; spores subglobose, 2-3 yu.

THE FUNGI WHICH CAUSE PLANT DISEASE 445

It parasitizes sugar cane, horse chestnut, chestnut, mulberry a.
and orange.

Fic. 316.—S. alneum. After Clements.

Marasmiez (p. 443)

Pileus tough, leathery, thin, membranous, or rarely somewhat
fleshy, reviving after drving with the return of moisture.
About five hundred fifty species.

Key To GENERA OF Marasmiee

Gills leathery-horny; spores black. ........ 1. Anthracophyllum.
Gills leathery; spores hyaline
Pileus not distinct from the stipe; sporo-
phore trumpet-shaped

Gills forked, edge blunt.............. 2. Xerotus.

Gills with a thin edge
Gills toothed on the margin. ...... 3. Lentinus, p. 445.
Gills with an even margin......... 4. Panus, p. 446.

Pileus distinct from the stipe
Annulus wanting

Pileus firm and dry. .............. 5. Marasmius, p. 446.
Pileus somewhat gelatinous. ....... 6. Heliomyces.
Annulus present.................5. 7. Merasmiopsis.

Lentinus Fries

Sporophore trumpet-shaped, pileus and stipe not distinct,
leathery, pileus central or lateral, gills toothed; spores white.
About three hundred forty species.

446 THE FUNGI WHICH CAUSE PLANT DISEASE

L. conchatus (Bul.) Schr. is found on birch, poplar, aspen.
L. lepideus *** Fr. on pine, birch, etc.

Fic. 317.—Lentinus lepideus. After Clements.

Panus Fries (p. 445)

This genus is very close to Lentinus from which it is separated
by the character of the gills which have an entire edge.
P. stipicus (Bul.) Fr. is perhaps parasitic occasionally.

Marasmius Fries (p. 445)

Sporophore tough, withering, often reviving in renewed moisture;
pileus, with few exceptions, regular, thin, leathery, without a veil,
sharply differentiated from the stipe, rarely sessile or laterally
attached; stipe tough, cartilaginous or horny, without an annulus;
gills tough, thin, leathery or membranous, entire margined.

Some four hundred fifty species of wide distribution, but chiefly
small tropical fungi.

THE FUNGI WHICH CAUSE PLANT DISEASE 447

Fig. 318.—Marasmius plicatus. After Fulton.

448 THE FUNGI WHICH CAUSE PLANT DISEASE

M. plicatus Wak.

Pileus submembranous, convex or subcampanulate, glabrous,
sulcate-striate, chestnut or light wine-colored; gills rather distant,
white, basally attached; stipe slender, glabrous above, white
downy below.

Marasmius parasitism of sugar cane was first described by
Wakker in 1895 ! later by Howard.! In these cases M. sacchari
or varieties of it were identified. In 1908 Fulton described M.
plicatus Wak. as the cause of serious sugar cane troubles in Louis-
iana. This fungus which exists first as a saprophyte resides
primarily in the soil from which it grows over the stools and
eventually ‘penetrates living tissue, destroys many roots and
smothers the developing buds. The white mycelium is found
cementing the lower leaf sheaths to the cane. It is probable that
several species are concerned.

M. sacchari Wak. occurs on sugar cane in the oriental tropics.

M. hawiiensis Cobb. is reported as associated with the preceding
species in Hawaii. M. semiustus B. & C. affects the stems, pedun-
cles and inflorescence of the banana. M. equicrinis Mill. Banc.
causes horse-hair blight of cacao and M. sarmentosus Fr. a simi-
lar disease of the tea plant and of forest trees in India.

Agariceze (p. 443)

This tribe contains all the gill fungi and is characterized by a
fleshy, putrescent sporophore; gills fleshy, rarely tough or leathery,
weak, easily broken, not deliquescent, without milky juice. It is
the largest tribe of the family. The genera are conveniently
grouped as black, brown, rusty, pink or red, and white-spored
forms. None of the black-spored species are known as parasites.

Amaurosporee (brown-spored series)

With a volva at base. .................. . 1. Chitonia.
Without a volva.
Veil remaining on the stem as an annulus
Gills free from the stem. ............ 2. Agaricus.
Gills united with the stem. .......... 3. Stropharia.

THE FUNGI WHICH CAUSE PLANT DISEASE 449

Veil remaining attached to the margin of
the pileus, often not apparent in very

old specimens ...............0005. 4. Hypholoma, p. 450.
Veil inconspicuous or wanting
GillS Pree aise darnrere eae Pas 5. Pilosace.
Gills decurrent. ................0005 6. Deconica.

Gills adnate or sinuate
Margin of pileus incurved when
YOUNG wal: Gest ides wae dad ax 7. Psilocybe, p. 451.
Margin of pileus always straight.... 8. Psathyra.

Phezosporeze (Rusty-spored series)

Annulus continuous

Vcil single, forming the annulus........ 1. Pholiota, p. 452.
Veil double, forming the annulus and
deciduous scales on the pileus. ..... 2. Rozites.

Annulus arachnoid, filamentous or evancs-
cent, often not apparent in old speci-

mens
Gills adnate; terrestrial. ............... 3. Cortinarius.
Gills decurrent; epiphytal.............. 4. Flammula, p. 452.

Annulus wanting
Gills decurrent; stipe with a cartilaginous

TWN pings peas se ese eee e ee 5. Tubaria.
Gills not decurrent
Stipe fleshy
Without a volva
Pileus fibrillous or silky. ........ 6. Inocybe.
Pileus smooth and viscid........ 7. Hebeloma.
With a volva...... 0.0... . ce eee eee 8. Locellina.

Stipe with a cartilaginous rind
Margin of pileus incurved when

YOUNG veto soe. Si eke geen elas 9. Naucoria.
Margin of pileus straight ‘
Pileus viscid; gills free........... 10. Pluteolus.

Pileus not viscid; gills attached... 11. Galera.

Rhodosporee (Pink-spored series)

Stipe lateral............. 2 eee eee eee eee 12. Claudopus.

Stipe central. {
Volva present; annulus wanting. ....... i 13. Volvaria, p. 452.

450 THE FUNGI WHICH CAUSE PLANT DISEASE

Volva absent; annulus present. ......... 14. Annularia.
Volva and annulus both wanting
Gills free from the stipe............. 15. Pluteus, p. 451.
Gills adnate or sinuate
Stipe fleshy. ...................., 16. Entoloma.
Stipe with a cartilaginous rind
Pileus torn into scales........... 17. Leptonia.

Pileus papillose, subcampanulate. 18. Nolanea.
Gills decurrent on the stipe

Stipe fleshy. ..................0.. 19. Clitopilus.
Stipe with a cartilaginous rind..... 20. Eccilia.
Leucosporez (White-spored series)
Stipe lateral, or none. ............ so heieatons 21. Pleurotus, p. 454.
Stipe central
Volva and annulus both present. ....... 22. Amanita.
Volva present; annulus none. .......... 23. Amantiopsis.
Volva absent; annulus present
Gills free from the stipe ............ 24. Lepotia.
Gills united to the stipe
Pileus usually smooth. ............ 25. Armillaria, p. 455.
Pileus floccose. ................--- 26. Costinellus.

Volva and annulus both absent
Gills decurrent on the stipe

Stipe fleshy. ..................... 27. Clitocybe, p. 457.
Stipe with a cartilaginous rind...... 28. Omphalia.
Gills adnate, stipe with a cartilaginous
PING: site en aa se ela ewes tt a 29. Collybia, p. 458.
Gills sinuate
Stipe fleshy. ..................0.. 30. Tricholoma, p. 460.

Stipe with a cartilaginous rind
Pileus membranous, more or less

StALE ss as as cent Se 31. Mycena, p. 460.
Pileus very thin, without a pelli-
CG, acc eichd nau athe i lee ge ces 32. Hiatula.

Hypholoma Fries (p. 449)

Fleshy; gills attached; annulus imperfect, or none; veil breaking
up into fragments which are more or less persistent on the margin
of the cap.

About seventy species.

THE FUNGI WHICH CAUSE PLANT DISEASE 451

H. appendiculatum (Bul.) Karst. is perhaps parasitic, occurring
at the bases of living trees.
H. fasciculare (Huds.) Fr. is said to grow parasitically upon

TI'ig. 319.—Hypoloma appendiculatum. After Clements.

roots, causing a white rot. It is mentioned as a parasite on rasp-
berry roots in Australia.14
H. lateritium (Schié.) Schr. is also possibly parasitic on trees.

Psilocybe Fries (p. 449)

Pileus smooth, margin at first incurved; gills and spores at
length brownish or purplish; stipe cartilaginous, hollow or stuffed,
veil absent or rudimentary.

About forty species. Fig. 320.

P. spadicea (Sché.) Fr. is a weak wound parasite on various
woody plants.

P. henningsii Jung. is said to be occasionally injurious to
winter grains } in Europe.

452 THE FUNGI WHICH CAUSE PLANT DISEASE

Pholiota Fries (p. 449)

Pileus symmetrical, more or less thick, fleshy, with a veil
which forms an annulus; gills adnate, becoming rusty at maturity.
Fig. 321.

P. aurivilla (Bat.) Quel. and P. squarrosa Mull. occur on
deciduous trees, especially on the
apple.

P. spectabilis Fr. is occasionally
parasitic on oaks.

P. mutabilis (Sché.) Quel. is a root
parasite on trees.

P. adiposa Fries.

Cap medium, 5-10 em. wide, yellow,
very sticky when moist, with spread-
ee ing or erect rust-brown scales which
Fic. 320.—Psilocybe pennata. sometimes disappear when old, convex

alter Cooke: to plane; stem 5-15 cm. by 1-2 cm.,
yellow, paler above and darker, scaly below the more or less im-
perfect tufted ring, solid or stuffed; gills adnate, yellowish to rust-
colored, broad, crowded; spores rust-colored, elliptic, 7-8 x 5 yp.
The name may refer to the sticky cap.

Chiefly a saprophyte, occasionally on living trees, both decid-
uous trees and conifers, as a wound parasite.

P. destruens Brand. occurs on poplar; P. cervinus Schi. on
various trees.

Flammula Fries (p. 449)

Pileus fleshy, margin at first incurved; stipe fleshy, fibrous,
well marked by the bright yellow or orange colored cap.

About sixty species.

F. alnicola Fr. is probably a root parasite.

F. penetrans Fr. and F. spumosa Fr. are regarded by Cavara 1%
as root parasites of forest trees.

Volvaria Fries (p. 449)
Fleshy; gills free, white, later pink; spores ellipsoid, smooth;

THE FUNGI WHICH CAUSE PLANT DISEASE 453

annulus none; volva present. Easily distinguished from all other
pink-spored genera by the volva. Fig. 322.
About thirty-six species.

Fic. 321.—Pholiota adiposa. After Clements.

V. bombycina (Schi.) Quel.

Cap large, 8-25 em. wide, all white and silky, more rarely some-
what scaly, hemispheric or bell-shaped to convex; stem 8-12 cm.
by 1-2 cm., white, smooth, tapering upward, solid, volva large
and spreading; gills free, salmon-pink, crowded, spores elliptic,
6-7 x 4 uw. It is often parasitic on various trees.

454 THE FUNGI WHICH CAUSE PLANT DISEASE

Pluteus Fries (p. 450)

Pileus fleshy, regular; separating easily from the stipe; gills
free: volva and annulus both absent; spores elliptic.

P. cervinus Sché. Fig. 323.

Cap large, 5-16 cm. wide, usually
some shade of brown, from grayish or
yellowish to blackish-brown, more or
less fibrous or hairy on the disk, some-
times sticky, convex or plane; stem 7-
15 cm. by 14-1 cm., brownish, smooth
or black-hairy, solid; gills free, pink,
broad; spores pink, rarely greenish,
globoid, 7-8 x 5-6 pu.

A common saprophyte which is oc-
casionally parasitic.

Pleurotus.Fries (p. 450)

Pileus laterally sessile, or excentrically
stipitate. Fig. 324.

A genus of about two hundred fifty
species.

P. ostreatus Jacq.

Cap large, 7-24 cm. wide, white, gray
or tan, smooth or more or less scaly in
age, convex or plane, shelf or shell-
shaped, more or less lobed and torn at
the margin; stem short and lateral, or none, white, solid, more or
less hairy at base; gills long-decurrent, connected by veins on the
stem, white or yellowish; spores elliptic, 8-10 x 4-5 u.

Common on deciduous trees, mainly saprophytic.

P. salignus Schrad. is often parasitic on willow, poplar, mul-
berry, etc.

P. ulmarius Bul.

Cap large, 8-15 cm. wide, white, whitish or tan, often brownish
toward the center, smooth, often cracked, usually convex, some-
times plane; stem long and stout, often nearly central, 5-12 cm.
hy 2-3 cm., white or tan, smooth or hairy toward the base, solid,

Fic. 322.—Volvaria bomby-
cina. After Clements.

THE FUNGI WHICH CAUSE PLANT DISEASE 455

elastic, often curved; gills annexed or sinuate, whitish, broad,
close; spores globose, 5-6 yp.
Parasitic on elm and maple or usually a saprophyte.

Fic. 323.—Pluteus cervinus. After Clements.

P. nidulans Pers. occurs on roots of trees in Europe.
Other questionable parasites are: P. atrocceruleus Fr. on wil-
low; P. mitis Pers. on pine; P. corticatus Fir. on poplar.

Armillaria Fries (p. 450)

Fleshy, the substance of the pileus and stipe continuous; annulus
fixed; gills usually attached, white; spores clavate, ellipsoid or
ovate, smooth.

About sixty species. Figs. 325, 326.

An extensive list of members of the genus, under the name
Agaricus, found growing upon woody plants has been compiled by
Wilcox.”

A. mellea (Vahl.) Quel.°” °° 4

Cap large, 8-15 cm. wide, usually honey-colored, but varying
through all shades of yellow to brown, typically marked with
small tufts of brownish or blackish hairs, especially toward the
center, though sometimes woolly or entirely smooth, margin often
striate, convex to expanded; stem tall, stout, 3-15 cm. by 6-20 mm.,
whitish, yellowish, or brownish, especially below the ring, smooth
or scaly, hollow or stuffed, ring usually thickish and conspicuous,

456 THE FUNGI WHICH CAUSE PLANT DISEASE

but sometimes thin or even lacking; gills touching broadly or
running down the stem, whitish or yellowish; spores elliptic or
rounded, 7-10 uz.

This is a common wound parasite of conifers and deciduous
trees, causing a root-rot. It also causes a potato disease in Aus-
tralia. The abundant mycelium is white and extends a meter

Tic. 324.—Pleurotus ostreatus. After Clements.

or more through the wood and bark, aggregating under or on the
bark to form shining hard gray-black intertangled cords (rhizo-
morphs) 1-2 mm. in diameter often reaching out to great distances
through the earth. Fig. 326. Sheets of white felt also occur.

The young mycelium grows into the cambium layer, attacking
living cells and often encircling the tree. In the living cortex it
presents a characteristic fasciated skin-like appearance.

THE FUNGI WHICH CAUSE PLANT DISEASE 457

The sporophores are borne in clusters in autumn on the ground
or on the bark.

The spores, sown in plum decoction, develop a mycelium which
soon produces rhizomorphs. These advancing give off delicate
hyphe which may penetrate into the host. The mycelium spreads

Fic. 325.—Armillaria mellea. After Clements.

most rapidly through the medullary rays and from them into other

tissue elements.
A. fuscipes Petch causes a root disease of Acacia in Ceylon.
A. mucida (Schriid.) Quel. is reported as a wound parasite of the

beech.
Clitocybe Fries (p. 450)

Pileus more or less fleshy, margin at first incurved; stipe fleshy,
often becoming hollow; gills decurrent.
About ninety species. Fig. 427.

458

C. parasitica Wil.”

THE FUNGI WHICH CAUSE PLANT DISEASE

Growing in dense clusters; pileus 6-8 cm., convex or umbonate,

Fig. 326.—Rhizomorphs of A. mellea.
After Freeman.

usually minutely scaly, mottled
buff to yellow-brown in color;
gills paler, becoming mottled,
at first noticeably decurrent;
stipe 10-16 cm. high, up to
1 ecm. thick, solid, usually
curved, darker than the pileus;
black rhizomorphs present.

It differs from Armillaria
mellea in having no annulus,
and in growing in denser clus-
ters.

The fungus causes a root-
rot very similar to that caused
by Armillaria mellea. There
are present typical subcortical
strands, mostly between the
cortex and cambium and some-

times characteristic subterranean black rhizomorphs adhering

close to the cortex of the roots.

Fungous branches enter the wood chiefly through the medullary
rays and there is later rapid vertical growth through the vessels

and tracheids.

The cell contents are destroyed, the hyphe often

forming loops around the nucleus. The sporophores occur in
groups at the base of the tree after the disease is well developed.
An extensive bibliography is given by Wilcox.”

Collybia Fries (p. 450)

Pileus thin, fleshy, margin at first incurved; stipe cartilaginous.
About two hundred seventy-five species. Fig. 329.

C. velutipes Curt.

Cap 2-8 cm. wide, yellow-brown or reddish brown, rarely paler
except toward the margin, smooth, very sticky when moist, con-
vex to plane or somewhat recurved, often excentric or irregular

* through pressure.

THE FUNGI WHICH CAUSE PLANT DISEASE 459

fier
et RO

YF
Fic. 327.—Clitocybe parasitica. After Wilcox

1 1G. 328.—Clitocybe parasitica, mycelium entering medullary ray. After Wilcox.

460 THE FUNGI WHICH CAUSE PLANT DISEASE

A common saprophyte which is reported by Stewart 1 as the
probable cause of death of the horse-chestnut. It has also
been reported in Europe as a
parasite.

Tricholoma Fries (p. 450)

Stout and fleshy, stipe
end pileus of the same sub-
stance; gills sinuate or ad-
nate. Fig. 330.

T. rutilans Scha. occurs on
pine roots; T. saponaceum I'r.
on various tree roots.

Mycena Fries (p. 450)

Small; pileus usually bell-
shaped, rarely umbilicate, membranous and more or less striate,
at first with the straight margin applied to the stipe; gills only
slightly toothed, not decurrent or only so by a tooth; stipe slen-
der, cartilaginous, usually _
hollow. Fig. 331.

A genus of some three
hundred species.

M. epipterygia Scop.

Five to ten cm. high;
pileus 1-2 cm. broad, vis-
cid when moist, ovate to
conic or campanulate,
later more expanded, ob-
tuse, the margin striate, .
sometimes minutely
toothed, grayish, in age
often reddish; stipe 2 mm.
thick, flexuous or straight
with soft hairs at the base; gills decurrent by a small tooth,
varying in color from whitish through gray to a tinge of blue or red.

Usually a saprophyte, but injurious to various kinds of trees.
Widely distributed in the North temperate zone.

Fic. 329.—Collybia velutipes. After
Lloyd.

Fic. 330.—Tricholoma. After Lloyd.

461

THE FUNGI WHICH CAUSE PLANT DISEASE

‘s]UIUIIIO IOV

‘BYVMIWayes BUddATY—'TEE “OL

462 THE FUNGI WHICH CAUSE PLANT DISEASE ~

Phallales (p. 395)

Mycelium rhizomorphic; sporophore with a fertile portion, the
gleba, which contains a series of labyrinthine spore chambers,
these lined by a hymenium of closely approximated basidia, the
supporting tissue parenchymatous, spongy and elastic in texture,
forming a receptacle which varies in size and form in the different
genera. Except in Rhizogaster the young sporophore is volvate,
and at the bursting of the volva immediately assumes its mature
size and form.

An order of less than fifty species of interesting, yet from their
foul odor most disagreeable fungi. At present they are regarded
as mainly saprophytes.

Key To Famiiies oF Phallales

Receptacle stipitate, tubular or cylin-

dric, capitate, with the gleba ex-

Lerma): coved soweyan eae hes eke sts 1. Phallacee, p. 462.
Receptacle latticed or irregularly

branched, sessile or stalked; gleba en-

closed by the receptacle............ 2. Clathracee, p. 463.

Phallacez
Key to Genera oF Phallaceze

Gleba borne directly on the upper portion of
the stem; no special pileus
Gleba smooth, even. .................. 1. Mutinus.
Gleba papillate or uneven.............. 2. Jansia.
Gleba covered by a rudimentary network 3. Floccomutinus.
Gleba borne on the outer surface of a special
pileus
Pileus even, rugose, or reticulate
Veil poorly developed or none........ 4. Phallus, p. 463.
Veil well developed
Surface of the pileus regularly reticu-
late ioe acivend een g or ekaese rs 5. Dictyophora, p. 463.
Surface of the pileus irregularly folded
: and convoluted. .............. 6. Clautriavia.
Pileus lamellate..................2.05. 7. Itajahya.

THE FUNGI WHICH CAUSE PLANT DISEASE 463

Phallus Linnzus (p. 462)

Stipe cylindric, even, bearing at the apex a
smooth, rugose, or reticulate pileus.

Less than ten species are known. The follow-
ing are of economic importance.

P. impudicus L.

This is one of the most widely distributed
species of the genus, but not so common in
America as in Europe. It is reported !° as the
cause of a root disease of the grape in Hungary.

P. rubicundus Bosc.

Cobb 1" has described a disease of sugar cane
as due to Ithyphallus coralloides. Lloyd,"
however, refers the causal fungus to the present
species, since he considers that all the red
forms of “ Phallus” constitute a single species.

Dictyophora Desvaux (p. 462)

Fig. 332.—Phallus
impudicus. After
Lloyd.

A species of this genus is suspected by Cobb ™* as one of the
causal fungi in a root disease of sugar cane in Hawaii.

Clathracez (p. 462)

The receptacle consists of a series of arms which are either

spreading, erect, or latticed.

Key to GENERA oF Clathracee

Receptacle of free arms, or lobes at the sum-
mit of the stipe

Stipe columnar, arms free.............. 1. Lysurus.

Stipe enlarged upwards
Limb of the receptacle with suberect

lobeSsAviiew eet twee earete Weeds 2. Anthurus,

TODOS seni Siocon boa can meena: 8. Asere.

Receptacle of simple, erect, columns, apical-
ly united and fertile only on their inner
side

Sessileies oso ccenaacan Gene talesies ose 4. Laternea, p. 464.
Stalked).occ< caus awudesuiedessicnwehais 5. Pseudocolus.

464 THE FUNGI WHICH CAUSE PLANT DISEASE

Receptacle clathrate or latticed

Sessile. ......

Stalked

6. Clathrus.

Receptacle a simple net
Stipe simple........ atime wha Ad 7. Simblum.
Borne on a series of columns which
are united basally into a hollow

tuber or eee reper ere 8. Colus.
Receptacle with the network covered
with knot-like projections. ....... 9. Klachbrennera.

Fic. 333.—Later-
nea columnata.
After Lloyd.

Laternea Turpin (p. 463)

Receptacle sessile, of upright, convergent
columns, apically united and fertile only on
the inner surface.

L. columnata (Bosc.) Ness. is recorded by
Cobb ™* as one of the fungi of the root disease
of sugar cane in Hawaii. The species is rather
common in the Southern United States, South
America, the West Indies and Hawaii.

Lycoperdales (p. 395)

Mycelium arachnoid to rhizomorphic; sporo-
phores from the first appearing as small balls
which enlarge to maturity, gleba internal at
maturity, becoming a powdery spore-mass; base

of the sporophore sterile; peridium double or single, parenchyma-
tous, separating into flakes or breaking regularly; fertile hyph,
persistent in the spore mass .as a capillitium which is usually at-
tached to the columella.

A single family Lycoperdacez with species which are usually

saprophytes.

Key To GENERA oF Lycoperdacee

Outer peridium fragile, more or less decidu-
ous, often warty, spiny or scaly
Capillitium of an even thickness, not

branched

THE FUNGI WHICH CAUSE PLANT DISEASE 465

Sporophore with a pronounced stcrile
persistent base. ................ 1. Lycoperdon, p. 465.
Sporophore without a pronounced
sterile base
Inner peridium opening irregularly.
Inner peridium opening by a basal
pore, the outer peridium break-
ing equatorially and the upper
half with the attached inner
peridium forcefully ejected. .... 3. Catastoma.
Capillitium free, short-branched with
pointed ends
Sporophore with a pronounced per-
sistent sterile base. ............. 4. Bovistella.
Sporophore without a pronounced
sterile base
Inner peridium papery, opening by an

bo

. Globaria.

apical mouth. ................ 5. Bovista.
Inner peridium thick, breaking
irregularly, capillitium spiny... 6. Mycenastrum.

Outer peridium splitting into star-like re-
flexed, persistent segments
Inner peridium opening byasinglemouth 7. Geaster.
Inner peridium opening by several mouths 8. Myriostoma.

Lycoperdon Tournefort

Sessile, with a pronounced
sterile base; peridium thin,
opening regularly by an apical
perforation, smooth, warty or
spiny; spore-mass and capilli-
tium filling the interior of the
sporophore with echinulate
spores and even, simple hy-
phe.

L. gemmatum Bat. is re-
ported by Cavara!! on fir
trees in Italy, sending its
rhizomorphic mycelial strands
through cambium and bark causing the destruction of both.

Fic. 334.—Lycoperdon gemmatum. After
Lloyd.

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466

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468 THE FUNGI WHICH CAUSE PLANT DISEASE

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470 THE FUNGI WHICH CAUSE PLANT DISEASE

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A

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472 THE FUNGI WHICH CAUSE PLANT DISEASE

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25 Halsted, B. D., N. J. B. 129: 1898.

2 Arthur, J. C., Ind. R. 13: 1901.

217 Smith, R. E., Bot. Gaz. 38: 19, 1904.

238 Smith, R. E., Cal. Bul. 172: 1906.

39 Smith, R. E., Cal. Bul. 165: 1905.

200 Stone, G. E. & Smith, R. E., Mass. B. 61: 1899.

241 Stevens, F. L., Pop. Se. Mo. May, 1911.

22 HS. R. 16: 380.

243 Bates, J. M., J. Mye. 9: 219.

24 Bates, J. M., Sc. 16: 138, 1902.

45 Trabut, L., Bul. Agr. Alg. & Tun. 13: 355, 1907.

24 Olive, E. W., S. D. B. 109: 1908.

247 Ward, M. H., Ann. Bot. 2: 217, 1888.

248 Eriksson & Henning, Zeit. 4: 1894.

2 Pritchard, F. J., Bot. Gaz. 52: 169, 1911.

260 Butler, E. J. and Hayman, J. M., India D. Ag. R. 1906, Bot. Ser. 1.

251 Lagerheim, G., Bot. Cent. 54: 324, 1893; Jour. Myc. 7: 327, 1891.

252 Barclay, A., Jour. Bot. 30, 1892.

268 Zukal, H., Untersuchungen iiber die Rostpilzkrankheiten des Get-
reides in Oesterreich-Ungarn 10: 16, 1900.

264 Loverdo, J., Les maladies cryptogamiques des cereales, Paris, 1892.

255 Lagerheim, G., Jour. Myc. 7:, 327, 1891.

256 Ward, H. M., Ann. Bot. 2: 229, 1888.

267 Dorset, P. H., Am. Flor. 15: 246, 1899.

* 268 Jaczewski, Zeit. 20: 321, 1910.

269 Eriksson, J., Ber. d. deut. Bot. Géz. 12: 292, 1894.

2% Arthur, J. C., Bot. Gaz. 38: 64, 1904.

21 Arthur, J. C., Sc. 29: 270, 1909.

2? Halsted, B. D., Bull. Torr. Bot. Cl. 25: 331, 1898.

263 Dudley, W. R., N. Y. (Cornell) B. 25: 154, 1890.

264 Tabenhaus, J. J., Phytop. 1: 55, 1911.

366 Eriksson, J., C. Bak. 31: 93, 1911.

2 Arthur, J. C., Ind. B. 84: 148, 1900.

#7 Jacky, E., Zeit 10: 132, 1900.

26 Stone, G. E., and Smith, R. E., Mass. R. 9: (Hatch) 1896: 176, 1898.

2? Arthur, J. C. and Holway, E. W. D., Minn. Bot. St. B. 2: 631, 1901.

20 Chifflot, J., J. Soc. Nat. Hort. Fr. 4: 348, 1907.

*1 Kusano, 8., Bull. Coll.. Agr. Tokyo Imp. Univ. 8: 27, 1908.

272 Clinton, G. P., Ill. B. 29: 273, 1893.

BIBLIOGRAPHY OF BASIDIOMYCETES 473

8 Newcomb, F. C., J. Myc. 6: 106, 1890.

*4 Richards, H. M., Proc. Am. Acad. A. & Se. 30: 30, 1898,
*75 Tranzschel, W., Hedw. 32: 257, 1893.

76 Arthur, J. C., Torreya, 9: 21, 1909.

*7" Kirk, T. W. and Cockayne, A. H., N. Zeal. D. Agr. R. 16: 108, 1908.
8 Cook, M. C., Jour. Roy. Hort. Soc. London, 26: 1901.

*” Bartlett, A. W., R. Bot. Gard. British Guiana, 20: 1906-1907.
° Montmartini, L., Atti. Inst. Bot. Univ. Pavia, 1904.

*1 Kusano, 8., Bull. Co. Imp. Tokyo, 1908.

82 Pettis, C. R., Forest Quart. 7: 231, 1909.

283 Hennings, P., Zeit. 12: 129, 1902.

#4 Stewart, F. C., Geneva, T. B. 2: 62, 1906.

286 Spaulding, P., B. P. I. Circ. 38: 1909.

28 Spaulding, P., B. P. I. Bul. 206: 1911.

*87 Hedgcock, G., Sc. 31: 751, 1910.

288 Shear, C. L., J. Myc. 12: 89, 1906.

289 Farlow, W. G., Anniv. Mem. Boston Soc. Nat. Hist. 1880.
2” Idem, R. 11: 348, 1898.

221 Kiihn, J., Bot. Zeit. 27: 540, 1869.

22 Freeman, Ann. Bot. 16: 487, 1902.

23 Ward, H. M., Ann. Bot. 16: 233, 1902.

24 McAlpine, D., Vict. D. Ag. 5: 1, 1891.

25 Kusano, 8., Coll. Agr. Imp. Univ. Tokyo, 1908.

26 Roze, B. 8. M. Fr. 88: 1900.

297 Klebahn, H., Ber. d. Deut. Bot. Gaz. 8. 59. 1890.

298 Klebahn, H., Hedw. 29, 27, 1890.

299 Tubeuf, K., C. Bak. 7, 445.

300 Halsted, B. D., N. J. R. 391, 1893.

401 Halsted, B. D., N. J. R. 279, 1892.

302 Lloyd, F. E. and Ridgway, C.S8., Ala. B. D. Agr. 39: 1911.
#03 Johnson, E. C., B. P. I. 224: 1911.

4 Trelease, Wm., Trans. Wis. Acad. 131, 1882.

35 Kern, F. D , Torrya 9: 4, 1909.

36 Freeman, E. M. and Johnson, E. C., B. P. I. 216: 1911.
37 Eriksson, J. P., Ark. f. Bot. Stockholm 8: 1909.

*08 Arthur, J. C., Proc. Soc. Prom. Agr. Sc. 23: 1902.

39 Arthur, J. C., J. Myc. 11: 53, 1905.

310 Stewart, F. C., N. Y. (Geneva) B. 328: 1910.

311 Klebahn, Zeit. 2: 18, 1902.

312 Eriksson, J., Kung. Svens, Vet.—Akad. Hand. B. 317: 6, 1904.
318 Sappin-Trouffy, P., C. R. 116: 211 and 1304, 1894.

474 THE FUNGI WHICH CAUSE PLANT DISEASE

314 Dangeard, P. A., C. R. 116: 267, 1893.

15 Pairault, G. and Raciborski, M., Jour. d. Bot. 9: 318, 1895.

216 Istvanffi, G., Ber. d. Deut. Bot. Gez. 1895.

317 Juel, Pring. Jahr. 1898.

318 Maire, C. R., Paris, 1900, July 9.

319 Maire, C. R., Paris, 1900, Dec. 24.

3 Olive, E. W., Phyto. 7: 139, 1911.

321 McAlpine, D., Ag. Vict. B. 14: 1891.

322 Montemartini, Atti d. Ell. Inst. Bot. Univ. di. Pavia, 6: 1897.

323 Figcher, E., C. Bak. 28: 139, 1910.

324 Selby, A. D., O. B., 139: 1903.

226 South, F. W., W. Ind. Bull. 2: 83, 1911.

3% Wolff, R., Avcidium pini and sein Zusammenhang mit Coleosporium
senecionis, Regia, 1876.

327 Clinton, G. P., J. Mye. 8: 128, 1902.

328 Petch, T., Cirs. and Agr. Jour. Roy. Bot. Gard. Ceylon 5: 89, 1910.

329 Pennington, L. H., R. Mich. Ac. Sce., 9.

330 B. P. I. Cire. 35, 8, 1909.

331 Spaulding Mo. Bot. Gard. R. 17, 53, 1906.

3x2 Y. B. U.S. D. Agr. 588, 1907.

333 V. Schrenk, Cont. Shaw School Bot. No. 14, 45, 1899.

334 Hedgcock, Sc. 29: 913, 1909.

335 Mycologia, 157, May, 1910.

33% Hedgecock, Sc. 29, 913, 1909.

a7 Y. B. U.S. D. Agr. 587, 1907.

338 Buller J., Ec. Biol, 1: 1, 1905.

339 Spaulding in Mo. Bot. Garden Report, No. 17.

+0 See Indian Forestry, 36: 559-562, 1910.

*41 Scholz Verhandl. K. K. Zool. Bot. Gesell. Wien. 47: 541-557, 1897.

442 Vermont Agricultural Experiment Repor. 342-347.

43 Plowright, C. B., B. M.S. Trans. 90: 1904.

34 Y. B. U.S. D. Agr. 587, 1907.

446 Lagerheim, G. J. Myc. 7: 44.

FUNGI IMPERFECTI (p. 64)

In the preceding pages it has been repeatedly evident that one
species of fungus may have two, even several different types of
spores; in the Erysiphales the perithecial form and the conidial;
in the Peronosporales odspores and conidia; in the Spheriales the
ascigerous form and several conidial forms; in the Basidiomycetes
the basidial form and various conidial forms; in the Uredinales
spring and summer stages and teliospores. In comparatively
few instances among the many thousand species of fungi are all
of the different spore forms belonging to the species known to
man. In very many cases the lower or conidial forms are known
without any higher spore form (ascigerous, basidial, or sexual form),
being known to be genetically connected with them, though it seems
very probable, reasoning by analogy, that these conidial forms
really constitute part of the life cycle of some fungus which em-
braces also a higher form of spore. It is probable, indeed certain,
that some of these conidial forms at present possess also higher, as
yet unknown, forms of fructification. It is likewise probable that
in many cases the conidial form, though it does not now possess
any higher spore form, did in its not remote phylogeny possess
such forms; indeed that all of them are phylogenetically related to
fungi which produced one of the higher types of spores.

In some cases even in the absence of the higher spore it is possible
to refer the fungus to its proper order as for example is the case
with the conidial forms of the Peronosporales, the summer or spring
forms of the Uredinales, or the Odéspora forms of the Erysiphales.

Regarding many thousands of other conidial forms such refer-
ence is impossible or hazardous, since from the conidial form the
form of the higher spore can be inferred with only a small degree of
accuracy or not at all. For example, the conidial form known as
Glceosporium in the higher form of some of its species proves to be
a Glomerella, in other cases a Pseudopeziza; some Fusariums
prove to belong to the life cycle of Nectria, others to that of Neocos-
mospora, etc.

475

476 THE FUNGI WHICH CAUSE PLANT DISEASE

In plant pathology and in systematic mycology it becomes
necessary to classify, for convenience of reference and designation,
these multitudinous conidial forms of which the higher spore
form is as yet unknown, which may exist now or which may have
existed only in the more or less remote past. From analogy it
is probable that most of them pertain to the Ascomycetes, though a
few may find place among other classes.

This whole group of forms, which is characterized chiefly by the
imperfection of our knowledge of them, is classed together under
the name Fungi Imperfecti.

The. Fungi Imperfecti are in a temporary way divided into
orders, families, genera and species as are other fungi, with full
recognition of the fact that future research will result in many
cases in the disclosure of higher spore forms and the consequent
removal of species to their proper place in the general scheme of
classification.

Recognizing the tentative nature of the genera in the Fungi
Imperfecti these are spoken of as “‘form-genera.”’

Pathologically, the Fungi Imperfecti are of high importance, often
occurring on leaves, stems, fruit, wood, bark, etc., as active parasites,
though very many are also saprophytes. Upon leaves they are
particularly common causing diseased areas known as “‘leaf spots.”

The Fungi Imperfecti display three principal types of fructifi-
cation, pycnidia, acervuli and hyphe.

Pycnidia are more or less spherical, hollow sporocarps on the
inside of which conidia are borne on stalks (conidiophores) arising
from'the base or base and sides. Figs. 349, 354. The pycnidium
may be of various colors though it is most commonly black or dark;
it may be superficial or imbedded, and with or without a beak
(rostrum). The opening for the escape of the spores (ostiole) may
be narrow, or wanting or it may be very large, round, irregular,
etc. The walls vary from extremely delicate to very thick, smooth
or variously provided with hairs, spines, etc.

As need arises, it is common to speak of micro-pycnidia, and
macro-pycnidia. Pycnidia with very small spores are sometimes
called spermogonia especially if the spores do not germinate, a cus-
tom to be deprecated.

The acervulus may be regarded as a pycnidium without its wall.

THE FUNGI WHICH CAUSE PLANT DISEASE 477

It consists of a close bed of short conidiophores. Figs. 371, 379.
Acervuli may be small or large, subepidermal, subcortical or super-
ficial and may or may not be provided with hairs (sete) Fig. 370,
of various kinds. An acervulus with a well marked basal stroma
is known as a sporodochium. Fig. 435. If the sporodochium stalk
is markedly developed the structure becomes a coremium. It is
sometimes quite difficult to distinguish between a pycnidium
with an extremely large ostiole, or one with a very thin wall, and
the acervulus. For such purposes thin longitudinal sections are
most useful.

Hyphe are conidiophores which grow free for some distance
above their supporting substratum and in more loose form than in
the acervuli, so that the terminal parts at least stand out as sep-
arate threads, Figs. 383, 384, 396, 410.

The hyphe may be simple and short, or long and much branched.
When the hyphe ‘are very short and closely crowded to form a
sporogenous cushion the condition of an acervulus is approached
and confusion arises.

The conidia borne in the pycnidia, acervuli or on the hyphe are
of as various forms and types as is well conceivable and are made
the chief basis for subdivision of orders into form-genera. They
may be simple or compound, of almost any color, and may be borne
in bisipetal succession in chains, or solitary, or in groups at the
apices of the conidiophores.

The following scheme of Saccardo presents the confessedly
artificial groups into which conidia may for convenience be divided.

ScHemMeE orf Spore SECTIONS.

Amerospore: spores 1-celled, not stellate, spiral or filiform.
Hyalospore: spores hyaline or clear, globose to oblong, continuous.
Pheospore: spores dark, yellow to black, globose to oblong, con-

tinuous.

Didymospore: spores, 2-celled.

Hyalodidymz: spores hyaline, 2-celled.
Phezodidymz: spores dark, 2-celled.

Phragmospore: spores 3 to many-celled by cross septa.
Hyalophragmiz: spores hyaline, 3 to‘inaniy-celled.

Phzophragmiz: spores dark, 3 to many-celled.

478 THE FUNGI WHICH CAUSE PLANT DISEASE

Dictyospore: spores septate, both crosswise and lengthwise, i. e.,
muriform.
Hyalodictyz: spores hyaline, muriform.
Pheodictyz: spores dark, muriform.
Scolecosporz: spores needle-shaped to filiform, continuous or septate.
Helicospore: spores spirally twisted, hyaline or dark, continuous or
septate.
Staurospore: spores stellate or radiate, hyaline or dark, continuous
or septate.

The mode of bearing spores and the color of the fungus both of
which it is seen are made the basis of classification have been shown
by Stevens and Hall} and others ? to-depend largely on environ-
ment, while the septation of the spores, also a fundamental char-
acter in present classification, depends often on the age of the
spores or on other factors. Many spores are unicellular until
germination begins but then become typically 2-celled; e. g.,
Gleeosporium. Such conditions have led to much inaccuracy. in
description and doubtless to undue multiplication of form-
species.

It has been quite customary, probably to some extent excusably
so, to describe as new a form-species when no form-species pre-
viously described for the same host or its near botanical kin could
be regarded as identical with it. Thus a Septoria found on Vitis
would ordinarily be regarded as new unless some of the Septorias
already described on some of the Vitacee seemed to be the same,
even though indistinguishable from dozens of Septorias on other
families of plants. This course has led to enormous multiplica-
tion of so-called species in these form-genera giving rise to such
form-genera as Septoria, Cercospora, and Phyllosticta with species
numbering more than 900, 500, 800, respectively.

The condition is much as is depicted by Cobb:? “Is a fungus
species newly found on a peach? Call it new and name it pruni.
Same genus on the grape—name it ampelinum. On the apple?
New, call it mali. On banana? Christen it muse. What next?
Sparrow in a pear tree, Passer pyri?”

Many of the form-genera are purely artificial—not at all well
founded, e. g., Phoma is separated from Phyllosticta only by the
supposed inability of the latter to grow on structures other than

THE FUNGI WHICH CAUSE PLANT DISEASE 479

leaves, a distinction which has been shown to be quite untenable.‘
It is evident that much careful study by cultures and cross in-
oculations is needed to reveal the true status in these Fungi.

Since the conception of species is here most loose the form species
given below must be regarded as purely tentative. The names are
to serve merely as handles for convenience in treating of the
various parasites and in only comparatively few instances do
they signify that they are really species. In many cases forms
appearing under two or more names may prove eventually to be

identical while in other cases forms may need to be sub-
divided.

Key to Orpers or Fungi Imperfecti

Conidia produced in pycnidia... .......... 1. Spheropsidales, p. 479.
Conidia not in pycnidia
Uyphez innate within the matrix........ 2. Melanconiales, p. 537.

Hyphe somewhat superficial, often floccose 3. Moniliales, p. 564.
Conidia or other special reproductive cells
UNKUMOWH 6s. sates gs saa eae aes oe 4, Mycelia sterilia, p. 659.

The Spheropsidales

Conidia in pycnidia which open by pores or slits, superficially
resembling the perithecia of the Ascomycetes.

The Sphzropsidales are preéminently leaf-spotting fungi though
many of them grow on fruit or stems causing blight, rot, cankers
etc. The vast majority are saprophytes or parasitic on tissues of
weak vitality, but not a few are active parasites.

Key To Famiuies or Spheropsidales

Pycnidia globose, conic, or lenticular
Pyenidia membranous, carbonous or
coriaceous, black...............- 1. Spherioidacesx, p. 480.
Pycnidia fleshy or waxy, light colored. 2. Nectrioidacex, p. 526.
Pycnidia more or less dimidiate, irregular
or shield-shaped, black............. 3. Leptostromatacez, p. 528.
Pycnidia cup-shaped or patelliform, black. 4. Excipulacez, p. 533.

480 THE FUNGI WHICH CAUSE PLANT DISEASE

The Spherioidacee (p. 479)

Pyenidia globose, ovate, or clavate, leathery to carbonous,
black or dark brown, opening by a pore, superficial, erumpent or
covered; stroma present or absent; conidia variable in form,
color, and division.

The family is subdivided according to its spores as indicated
below. ,

Key ro Sections or Spherioidacee
Conidia globose to elongate, straight or

falcate, 1 to many-celled
Conidia 1-celled, globose, ovate or elon-

Gates csgercevcoe temas sarees I. Amerospore.
Conidia hyaline... ................ 1. Hyalospore, p. 480.
Conidia colored................... 2. Phezospore, p. 500.
Conidia 2-celled, ovate to elongate.... II. Didymospore.
Conidia hyaline... ................ 3. Hyalodidyme, p. 505.
Conidia colored................... 4. Pheodidyme, p. 509.
Conidia 3 to many-celled, by transverse
septa, elongate ................. III. Phragmospore.
Conidia hyaline.. ................ 5. Hyalophragmie, p. 513.
Conidia colored................... 6. Pheophragmie, p. 514.
Conidia muriform, ovate to elongate. . IV. Dictyospore.
Conidia hyaline... ................ 7. Hyalodictye.
Conidia colored................... 8. Pheodictye, p. 516.
Conidia filiform, 1 to many-celled, hyaline
Or coloted.,. i. i004 es aae seven es V. 9. Scolecospors, p. 517.
Conidia cylindric, spirally coiled, 1 to
many-celled, hyaline or colored..... VI. 10. Helicospore.
Conidia stellate, 1 to many-celled, hyaline
COLOTE ieieis aces sym yaaa ataes @ ereatincs VII. 11. Staurospore.

Spherioidaceee—-Hyalospore
Spores hyaline, 1-celled, spherical, elliptical or long.

Key to Genera or Spherioidaces-Hyalospore

Stroma none; pycnidia separate.
Pyenidia smooth
Conidia borne singly

THE FUNGI WHICH CAUSE PLANT DISEASE

Conidia unappendaged
Pycnidia free in the substratum; sub-
iculum none
Pycnidia not beaked, opening by a
pore, or irregularly
Not growing on other fungi
Pyenidia opening by a regular pore
Pycnidia more or less sunken in the:
substratum
Pycnidia globose, etc. not spindle-
shaped
Pycnidia borne on dark colored
spots, or on wood, globose
Conidiophores simple or nearly
so
Pycnidia rather large
Pyenidia at first covered,
then erumpent
Spores under 15 wu
On leaves only..........
Not on leaves. ..........
Spores over 15 H..........
Pycnidia from the first super-
ficial esis asGee se
Pyenidia very small, closely
aggregated on dark spots
on the leaf.............
Conidiophores branched. .....
Pycnidia scattered, superficial,
circular, conidia elongate or
cylindric. ................
Pycnidia globose; conidiophores
CIRCINALEs 4.6 hs Bee ea exe es

Pycnidia opening irregularly, or
operculate
Spores globose..................
Spores elongate or ellipsoid
Pyenidia operculate. ...........
Pycnidia opening irregularly

481

. Phyllosticta, p. 483.

. Phoma, p. 490.

. Macrophoma, p. 493.
. Apospheria, p. 494.

. Asterostomella.

. Dendrophoma, p. 494.
. Crocicreas.

. Pyrenotrichum.

. Glutinium.

. Mycogala.

. Piptostomum.

482

Spores pointed. .............. 12
Spores blunt. ................ 13
On Erysiphacerz.................- 14
Pycnidia beaked. .................. 15
Pycnidia on a subiculum
Conidia ovate or elongate
Subiculum of simple hyphe ,
Pyenidia free. ................... 16
Pycnidia sunken in the subiculum.. 17.
Subiculum radiate. ............... 18
Conidia Y-shaped.................. 19
Conidia appendaged.. .............. 20.
Conidia in chains
Conidial chains separate and simple... 21

Conidial chains connected, often form-

Pycnidia appendaged or hairy
Appendages simple
Pycnidia with short simple tubercles;
conidia irregular in outline. .......
Pycnidia with long bristles; conidia
regular
Bristles septate, usually covering the
entire pycnidium, conidia cylin-
dric fusoid, usually curved.......
Bristles usually only at the apex;
conidia ovate, elongate or cylin-

dric, straight................... 25
Appendages stellate at the apex........ 26
Pycnidia stromatic, superficial or sunken
Pycnidia single on the stroma
Pycnidia with a single chamber
Conidiophores filiform. ............... 27
Conidiophores indistinct or absent
Stroma indistinct................... 28
Stroma rather well developed......... 29
Pycnidia typically with more than one
chamber.................0.00000 12
Pycnidia with well developed stroma, free
or buried

Pycnidia with separate mouths

23.

THE FUNGI WHICH CAUSE PLANT DISEASE

. Sclerotiopsis.
. Plenodomus.
. Cicinnobolus, p. 494.
. Spheronema, p. 494.

. Byssocystis.

. Chetophoma, p. 495.
. Asteroma, p. 496.

. Ypsilonia.

. Neottiospora.

. Sircoccus.

. Pecia.

Muricularia.

. Vermicularia, p. 496.

. Pyrenocheta, p. 497.
. Staurocheta.

. Phomopsis, p. 493.

. Plenodomus.
. Sclerophoma.

. Sclerotiopsis.

THE FUNGI WHICH CAUSE PLANT DISEASE 483

Pyenidia single on the stroma. ........ 30. Dothiopsis.
Pycnidia several on each stroma
Conidia separate from each other
Pycnidia scattered irregularly
Stroma sharply defined, globose, etc.
Pyenidial chambers appearing as
enlargements from without... 31. Anthracoderma.
Pycnidial chambers not as above
Stroma valsoid

Conidia straight
Conidia large, fusiform. ....... 32. Fusicoccum, p. 498.
Conidia small, ovate, clavate or
cylindric
Conidia ovate or clavate, very
£51.14: Cane gee eae a 33. Cytosporella, p. 498.
Conidia larger, ovate, or elon-
gate
Pyenidia superficial or sub-
superficial
Conidiophores simple....... 34. Dothiorella, p. 499.
Conidiophores branched. ... 35. Dothiorellina.
Pycnidia deep seated. ....... 36. Rabenhorstia.
Conidia allantoid. ........... 37. Cytospora, p. 499.
Stroma pulvinate................- 38. Fuckelia, p. 500.
Stroma indefinite, on black spots on
the host plant. ............... 39. Placospheria.
Pyenidia regularly arranged on the
stroma around a sterile center... 40. Lamyella.
Conidia adhering basally in fours. ..... 41. Gamosporella.

Pyenidia on each stroma with a com-
mon ostiole
Stroma globose or flask-shaped; conidia
CUIVED sch Ge need dota 42. Torsellia.
Stroma conic-truncate, conidia elongate
cylindric, straight. .............-. 43, Ceuthospora, -p. 500.
Stroma thin, effuse; conidia curved to
allantoid... ........... 0c eee ee ees 44, Plagiorhabdus, p. 500.

Phyllosticta Persoon (p. 481)

Pycnidia immersed, erumpent or with the beak piercing the

484 THE FUNGI WHICH CAUSE PLANT DISEASE

epidermis, lenticular to globose, thin membranous, opening by
a pore; conidia small, ovate to elongate, continuous, hyaline or
green; conidiophore short or almost obsolete. On leaves.

In part =Guignardia, Valsonectria, Mycospherella.

The genus is a very large one of some eight hundred forms, few of
which have been adequately studied. It differs from Phoma only in
that it is foliicolous while Phoma is caulicolous, a distinction which

XX I

Tic. 335.—P. solitaria. 1, section through apple; 4, spores
from apple blotch showing appendages; 6-7, germinating
spores; 9, mycelium from corn-meal cultures. After Scott
and Rorer.

is not consistently maintained and which is untenable for generic
limitation (see p. 478).

The fungus produces leaf spots by killing or weakening the
leaf tissue with its mycelium. The spots are circular or subcircular,
unless rendered angular by obstruction by veins, and the pycnidia
may usually be seen with a lens in old spots unless the color of the
leaf forbids. Similar effects follow on fruits.

P. ampelopsidis E. & M. on Ampelopsis is probably identical
with P. labrusce =Guignardia bidwellii. See p. 238.

P. bellunensis Mart. on elm =Mycospherella ulmi. See p. 249.

P. brassice (Carr.) West on cabbage, etc. =Mycospherella bras-
siecola.2 See p. 249.

P. labrusce Thiim. on the grape =Guignardia bidwellii. See
p. 238.

THE FUNGI WHICH CAUSE PLANT DISEASE 485

P. tabifica Prill is perhaps identical with Mycospherella tabifica,
though Potebnia® questions this. See p. 247.

P. maculiformis (Pers.) Sace. on chestnut =Mycospherella
maculiformis. See p. 249.

P. solitaria E. & E.” 8

Perithecia minute, immersed, the ostiole only erumpent; conidia
broadly elliptic, 8-10 x 5-6 yu, surrounded by a mucilaginous sheath.

It is the cause of apple fruit blotch and of cankers and leaf spots.
On the fruit it was first reported by Clinton? in 1902.. The fruit
spots show a characteristic fringed appearance owing to the
unequal advance of the mycelium which is limited to the outer-
most fruit cells. In the fruit the pycnidia develop subepidermally.

Fic. 336.—P. solitaria. 1-month-old colony on apple agar. After

Scott and Rorer.
The fungus was grown in pure culture and its identity on twig,
leaf and fruit was shown by cross inoculation.

P. persice Sacc. is common on peach leaves.

P. piricola Sacc. & Speg. is found on apple and pear.

P. limitata Pk." is reported as the cause of an apple leaf spot.

Spots round minute, 2-6 mm., brown or reddish; pycnidia epiph-
yllous, black, few, punctiform; spores ellipsoid, 7-8 x 4 y. P. mali
P. & D. occurs on apple and pear.

P. pirina Sacc.!!

Spots variable; pycnidia epiphyllous, punctiform, lenticular,
100-130 yw, context loosely cellular, brown; conidia ovoid to
ellipsoid, 4-5 x 2-2.5 yp. -

This was long regarded as the chief factor causing the common
leaf spot on the apple and pear. Recent work throws doubt on this.

486 THE FUNGI WHICH CAUSE PLANT DISEASE

P. circumscissa Cke.

Amphigenous; spots orbicular, reddish-brown, at length de-
ciduous; pycnidia scattered, minute; conidia elliptic, 8x2 yu.

Spots and shot holes are formed on drupaceous hosts.

P. prunicola Sacc.}?

Spots subcircular, epiphyllous, sordid-brownish or ochraceous,
margin subconcolorous; pycnidia scattered, punctiform; conidia
ovoid to ellipsoid, 5 x 3 yu.

It is found on Prunus, causing leaf spots in Europe, America
and Australia. Scurf is also produced on apple bark.

P. armenicola Far. is associated with an apricot fruit disease.

P. grossularie Sacec. grows on Ribes grossularia.

P. fragaricola D. & R. is widespread in Europe on the strawberry.

P, vitis Sacc. and P. succedanea (Pass.) All. are found on grape
in Europe. .

P. viale R. & G. also parasitizes the grape.

P. bizzozeriana Mass. in Hungary produces a grape disease
superficially resembling black rot.1°

P. putrefaciens Sh. occurs on cranberry.

P. olez Pet. and P. insulata Mont. cause leaf spots on the olive.

P. cannabinis Kirch forms spots on hemp leaves;

P. humuli Sacc. & Speg. on the hop.

P. bataticola E. & M. Pyenidia scattered, minute, black; spots
small rounded, whitish with a purple margin; conidia ellipsoid,
5 x 2u. Leaf spots are produced on the sweet potato.

P. nicotiana E. & E.

Spots brown, reddish, zonate; pycnidia 200 yu, black; conidia
3.5-5 x 1.5 uw. It causes leaf spots of tobacco;"4

P. tabaci Pass. also occurs on Nicotiana.

P. medicaginis (Fel.) Sacc. occurs on alfalfa; 15

P. japonica Miy. and P. miuria Miy. parasitize rice.

P, bete Oud.

Spots grayish-ochre, large and irregular; pycnidia epiphyllous,
minute, densely clustered, brownish, subimmersed; conidia elliptic,
5-6 x 3 p.

It is mentioned by Stewart” as the cause of leaf spots of beets.

P. malkoffi Bub. causes cotton leaf spots in Bulgaria.

P. coffeicola Del. and P. comeensis Del. are on coffee;

THE FUNGI WHICH CAUSE PLANT DISEASE 487

P. cinnamoni Del. on cinnamon leaves;

P. hevea Zimm. on Para rubber.

P. hortorum Speg.!® 1°

Spots circular, indefinite, fulvous, gray in the center, amphig-
enous, at last falling away; pycnidia in the center of the spot,
minute, 80-90 y, globose-lenticular, thin, membranous, dull
fusco-olivaceous; conidia elliptic to ovoid, rounded at the ends,
4-6 x 2-2.5 p.

It produces spots on leaves and fruit of egg plant in Europe
‘and America.

P. chenopodii Sacc.”

Spots irregular, scattered or confluent, ochraceous, fuscous
margined; pycnidia lenticular, punctiform, 50 »; conida oblong-
elliptic, 5 x 3 ». A leaf spot is produced on spinach.

P. apii Hals."* forms brown spots on leaves of celery; pycnidia
punctiform, black; conidia elliptic to ovate oblong.

P. phaseolina Sacc.

Spots irregularly scattered, subcircular, 2-10 mm., deep rusty
brown, becoming lighter in center and darker margined; pycnidia
scattered, 70-90 yu; conidia ovoid oblong, 4-6 x 2-2.5 u.

It causes spotting of bean and cowpea.*®

P. cucurbitacearum Sacc.

Spots epiphyllous or amphigenous, sordid, whitish; pyenida punc-
tiform, 80-100 u, lenticular; conidia oblong, 5-6 x 21% u, curved.

On muskmelon, cucumbers and other cucurbs, spotting the
leaves. 1 21-28

P. citrullina Chester * is also reported on melons,

P. maculicola Hals.2! produces spots in Dracena and related
plants.

P. hedericola Dur. & M. and P. hederacea (Arc.) All. cause
spots on Hedera leaves,?* 4

P. rose Desm. and P. argillaceze Bres. occur on roses.

P. rosarum Pass. causes a black spot on roses in New South
Wales.

P. altheina Sacc.®

Spots irregular, with a dark brown margin; pycnidia few,
lenticular, 90 », ochraceous; conidia ovate-oblong, 6-7 x 3-4 un.

On hollyhock in Italy, France and America.

483 THE FUNGI WHICH CAUSE PLANT DISEASE

P. ideecola Cke. forms spots on cultivated species of Sida and
Hibiscus.

P. dianthi West. grows on Dianthus leaves.

P. primulecola Desm. occurs on Primula leaves.”

Amphigenous; spots large, white, light margined; pycnidia epiph-
yllous, numerous, prominent, globose, black; conidia subglobose.

P, viola Desm.?” #

Amphigenous, spots white, round; pycnidia numerous, minute,
brown; spores minute, subcylindric, 10 » long.

Common, causing leaf spots on pansy and violet.

P, hydrangee E. & E.8

Spots 1.5-1 em. or more, rusty brown, margin narrow, raised,
at first shaded with purple; pycnidia epiphyllous, lenticular,
100-115 y; conidia oblong, 10-12 x 2.5-3.5 y.

On Hydrangea causing leaf spots.

P. syringze West. is common on lilac.

P. halstedii E. & E.

Amphigenous, spots roundish, reddish-brown, 4-114 cm. con-
centrically zonate, pycnidia few, lenticular, 100-150 y, immersed;
conidia broadly fusoid-oblong, 15-20 x 5-7 yw. Causing a leaf spot
of the lilac.

P. cruenta (Fr.) Kick.

Spots subcircular, reddish, becoming paler in the center; pycnidia
gregarious or scattered, globose-lenticular, dark olivaceous; conidia
ovate-oblong, 14-16 x 5.5-6.5 u; conidiophores, cylindric, 10-12x4 u.

It causes leaf spots of cultivated Solomon’s Seal.

P. cyclaminis Brun. occurs on cyclamen;

P. digitalis Bell on digitalis.

P. chrysanthemi E. & D.*

Spots purplish-brown, pycnidia 80-100 »; conidia 4-5 x 2.5-3 p.

It causes leaf spots on cultivated chrysanthemums.

P. leucanthemi Speg. is occasionally found in spots of chrysan-
themum leaves.

P. richardiz Hals.% is common as a leaf spotter of the calla
lily but has not been satisfactorily described.

P. opuntiz Sacc. & Speg. occurs on various of the Cactacer;

P. liliicola Sacc. on lily;

P. vince minoris B. & K. on Vinca minor;

THE FUNGI WHICH CAUSE PLANT DISEASE 489

P. pteridis Hals. causes blighting of cultivated Pteris; 2!

P. narcissi Aderh. of narcissus.””

P. cavare Trinch. produces white spots on leaves of Anthurium.®!

P. draceenz causes spots on Draczna leaves.

P. funckia Hals. Pycnidia 75-150 yp, straw colored.

The cause of leaf spots of cultivated Funkias.?”

P. dammarz is found on Dammara in Italy;

P. nobilis Tham. on Laurus.

P. ulmicola Sacc.

Spots indefinite, ochraceous, margin concolorous; pycnidia gre-
garious, punctiform, 70-80 yu, lenticular; conidia oblong ellipsoid,
6-3 uw. It infests elm leaves.!4

P. acericola C. & E.*?

Spots irregular, fuscous, brown margined; pycnidia densely
scattered on the central part of the spot, subepidermal, flask-
shaped, dark brown, 120 yu; conidia ovate, 8-9 x 5-6 u.

It causes serious leaf spotting of maples throughout the United
States.

P. aceris Sacc. forms small spots on maple leaves.

P. paviz Desm.

Spots indeterminate, reddish, lighter margined; pycnidia
epiphyllous, black; conidia cylindric-elliptic, 11-12 » long. It
is said to be common on sculus.'4

P. spheropsidea E. & E.*°

Epiphyllous; spots reddish-brown, margin lighter, scattered
or confluent, 1-2 cm.; pyenidia scattered, immersed, punctiform,
erumpent above, subepidermal; conidia globose to broadly ellip-
soid, hyaline, 12-15.5 x 8-10 u.

It causes serious leaf spotting of chestnuts throughout the
United States. ;

P. tilie Sacc. & Speg. is found on Tilia.

P. minima (B. & C.) E. is on Negundo.

P. catalpz E. & M.

Spots, rounded, brown, 3-6 mm., often confluent; pycnidia
subcuticular, small, black, scattered, 112 x 84; conidia ovate, 5-7 x
2.5-4.5 p. It causes leaf spots on Catalpa.*4

P. magnoliz Sacc. causes.leaf spots on Magnolia; P. viridis E. &
K. on ash; P. ilicina Sacc. on the cork oak.

490 THE FUNGI WHICH CAUSE PLANT DISEASE

An unidentified species has been reported on watermelon * as
cause of considerable injury. Halstead mentions also an undeter-
mined species on oats.° Pycenidia 150-250 yw; spores 12-18 x
6-7 uw, pyriform.

Phoma (Fries) Desmaziere (p. 481)

The genus as at present recorded contains over 1200 forms.
It is indistinguishable from Phyllosticta (see p. 484) except that
it is caulivorous. Several species are regarded as conidial forms
of Diaporthe, Mycosphaerella, etc.

P. reniformis on grape =Guignardia bidwellii. See p. 238.

P. albicans Rob. & Desm. on chicory =Pleospora albicans.
See p. 260.

P. bete Fr. on beet =Mycospherella tabifica. See p. 247.

P. bohemica Bub. & Kab. on fir tree needles = Rehmielliopsis.
See p. 276.

P. ambigua (Nitz.) Sacc. on pear=Diaporthe ambigua. See
p. 279.

P. sarmentella Sacc. on hop=Diaporthe sarmentella. See
p. 279.

P. persice Sacc.

Pycnidia scattered to gregarious, globose lenticular, */.—'/s mm.;
conidia oblong ovoid, 8-3 x 24, conidiophores cylindro-conical,
equal in length.

It produces constriction and death of peach twigs.*

P. maliS. & 8.3” 3

Pycnidia gregarious, subcuticular, depressed, ostiole erumpent;
conidia oblong-fusoid, 2-3 x 5-8 yu.

It attacks the wood of young apple trees and also causes a decay
of the fruit.

P. cydonie Sacc.®

Pycnidia subgregarious, depressed, ostiole obtuse or erumpent,
conidia elliptic oblong, 8-9 u long; conidiophores short.

A form causing rot of quince fruit was provisionally referred
to this species by Halsted.

P. limonis Tham. & Boll. P. citri Sacc. and P. aurantiorum
(Rab.) Sace. occur on citrous fruits;

THE FUNGI WHICH CAUSE PLANT DISEASE 491

P. pomarum Thim. on pomaceous fruits in Europe.

P. myxiz Far. is associated with an apricot fruit spot.

P. omnivora McA. is described as the cause of Australian wither
tip of the orange “° while to P. citricarpa McA is attributed another
common Australian citrous fruit disease.

P, mororum Sacce. is on Morus.

P. tuberculata McA. causes a disease of grape berries: in Aus-
tralia.*!

P. lophiostomoides Sacc. is common and perhaps parasitic on
cereals.

P. hennebergii Kiihn produces brown spots on the glumes of
wheat and leads to some injury to the grain.“

P. solanicola P. & D.** causes a disease of potato 1 stems in
France.

P. solani Hals.*

Pycnidia innate, depressed, oblong; conidia oblong.

On egg plant causing damping-off of seedlings.

P. subcircinata E. & E.

Pycnidia black, 70-90 y; conidia 5-6 x 2-2.5 p.

Spots are produced on bean pods.

P. sanguinolenta Rost.*4

Pycnidia scattered, subglobose; conidia ellipsoid, 4-6 x 1.5-3
#3 surrounded by a slime which gives the spore-mass a violet-red
color.

As the causé of a rot of carrot roots it has been reported in New
Jersey.

P. oleraceze Sacc.**-*

Pycnidia scattered, globose depressed, papillate, sunken in
the tissues, 144-14 mm.; conidia oblong, subcylindric, medially
constricted, apically obtuse, 5-6 x 2 y.

Manns notes this fungus causing a serious cabbage disease in
Ohio. The pycnidia are sparse on oval sunken diseased areas on
the stems, and bacterial invasion follows soon in leaves, cam-
bium and xylem. The cambium is rapidly destroyed and the
plant collapses. Bos“ and Quanjer“ have demonstrated the
pathogenicity of the fungus.

P. napobrassice Rost. causes rot of mangolds in Den-
mark; ‘**! also recently reported from Canada.*”

492 THE FUNGI WHICH CAUSE PLANT DISEASE

P. apiicola Speg. is recorded on celery.”

P. brassice Thiim. on cabbage is probably identical with
P. oleracez.

P. roumii Fron. is said to cause a serious cotton disease in
Africa.®?

P. batate E. & H.*4

Pycnidia blackish, gregarious, immersed; conidia terete, ovoid;
conidiophores slender. The cause of dry rot of sweet pota-
toes.

P. chrysanthemi Vogl. is found on leaves of chrysanthemum
causing them to wilt.

P. malvacearum West is noted on European hollyhocks;

P. devastatrix Berk. on cultivated lobelias;

Fic. 337.—P. oleracea. A, showing pycnidia with spores stream-
ing out; B, section; C, spores. After Manns.

P. dahliz Berk. on stems and flowers of Dahlia.

P. cyclamenz Hals. is given as the cause of Cyclamen leaf spots
but without ample description.

P. oleandrina Del. is on the rose, laurel, etc.

P. pithya Sacc. seems to be parasitic on the fir causing con-
striction and death of twigs.

P. strobi (B. & Br.) Sacc. is prevalent on white pine in Europe.

P. strobilinum P. & C. is closely related to the above.

P. sordida Dur. & M. occurs on Carpinus.

P. ribesia Sacc. Pycnidia collected, erumpent, spores oblong-
fusoid, 10 x 314 u, hyaline. In branches of Grossulariz.

Several undetermined species have been reported, among them

THE FUNGI WHICH CAUSE PLANT DISEASE 493

one on snapdragon,” another on Clematis roots, and one on ap-
434
ple

Phomopsis Saccardo ™ (p. 482)

As in Phoma, but with hooked conidiophores. A small genus.

P. aloeapercrasse Trinch. is reported on scapes and flowers of
the aloe in Italy.

P. stewartii Pk.

Perithecia gregarious, commonly occupying grayish or brown
spots, thin, subcutaneous, at length erumpent, depressed, minute,
*/s-"/2 mm. broad, black; spores of two kinds, first; filiform, curved,
flexuous or uncinate, hyaline, 16-25 x 1-1.5 y, second; oblong or
subfusiform, hyaline, commonly binucleate, 8-12 x 2-3 4;
sporophores slender, equal to or shorter than the spores.

The fungus with its filiform spores only was noted as a parasite
on Cosmos by Halsted who referred to it as a species of Phlyctzena.”
It has been noted in New York by Stewart,” and is destructive
both in the greenhouse and in the open.

Macrophoma Berlese & Voglino (p. 481)

As in Phoma, but the ostiole of the pycnidium not papillate,
and the pore smaller; conidia over 15 » long; conidiophores sim-
ple, short or filiform.

About one hundred seventy-five species.

M. hennebergii (Ktthn) Berl. & Vogl. causes a serious disease
on wheat in Sweden.®

The fungus which appears in the literature as M. curvispora
Pk. is in reality Gloeosporium malicorticis, see
p. 542, and that referred to as M. malorum &
is Myxosporium corticolum. See p. 546. E®

M. vestita Prill. & Del. attacks cacao in Fed
Ecuador. ea)

M. dalmatica (Tham.) B.& V.parasitizes the 5, 338M. curvi-
olive; M. taxi B. & V. attacks the leaves of spor, spores. Af-
Taxus; M. abietis M. & H. is associated with ”

a fir disease; M. manihotis Hem. is on cassava; M. ligustica Mag-
nag on Hydrangeas; M. helicinia Magnag on ivy.

494 THE FUNGI WHICH CAUSE PLANT DISEASE

M. reniformis (V. & R.) Car. is reported on grapes in Algiers,
Italy and Russia.

Apospheeria Berkley (p. 481)

Pycnidia globose, carbonous, with a papillate ostiole, erum-
pent or superficial; conidia elongate to globose; conidiophores
very short or absent.

One hundred species are recognized.

An undetermined species was found by Stevens 7! in New York
and New Jersey in 1892, causing diseased spots on strawberry
leaves.

Dendrophoma Saccardo (p. 481)

Pyenidia superficial or subepidermal and erum-
pent, carbonous; ostiole papillate; conidia elongate;
conidiophores branched.

A genus of some fifty species, chiefly sapro-
phytes.

D. marconii Cav. occurs on hemp stems; D. con- Fic. 339.—Den-
vallariz Cav. on leaves of Convallaria majalis; toate Bee
D. valsispora Penz on living lemon leaves. and conidia,

Cicinnobolus Ehrenberg is frequently met as a cher.
parasite on the mycelium of the Erysiphales.

Macrodendrophoma salicicola on Salix =Physalospora gregaria.
See p. 252.

Spheronema Fries (p. 482)

Pycnidia superficial or not, pyriform, cylindric or globose,
rostrum long; conidia ovate or elongate.

Some seventy-five species, chiefly saprophytes, have been de-
scribed.

7 ee Desm. on clover =Pseudopeziza trifolii. See
p. ;

S. fimbriatum (E. & H.) Sace.5* &

Pycnidia globose, 100-200 u, surrounded by septate, hyaline

THE FUNGI WHICH CAUSE PLANT DISEASE 495

hyphe, rostrum, 20-30 u long, apically fimbriate; conidia globose-
elliptic, 5-9 y.

The fungus grows in the sweet potato producing dark, almost
black spots in the skin. The tissue below becomes olive-green.
The dark mycelium is found penetrating
through and between cells of the dis-
eased area where numerous olivaceous
conidia are also present. The elon-
gated beaks of the pycnidia rise like a
small forest from the surface of the
potato.

In artificial culture the mycelium is
dark, abundantly septate and with nu-
merous oil globules. Long multiseptate ‘ i
conidiophores with light colored tips pig, 340,—S. fimbriatum; 1,
arise from the medium. From these ioe eek eeesier et a
hyaline conidia are produced, appar- olive conidia, After Halsted
ently endogenously. Fig. 340, Oliva- scoala
ceus, globose to elliptical, Fig. 340, conidia are formed within the
medium on branches of the mycelium in much the same manner.
The pycnidia develop in about nine days after inoculation and the
conidia are extruded from the fimbriate mouth of the long ros-
trum.

Inoculations proved the pathogenicity of the organism,
typical black rot appearing in about three weeks after infec-
tion.

S. adiposum Butler causes a black rot of sugar cane.

S. pomarum Sh. is on cranberry.

S. spurium (Fr.) Sacc. on Prunus is often reported as Dematium
prunastri.

S. oryze Miy. is on rice.!®

Chetophoma Cooke (p. 482)

Pycnidia superficial, very small, on a subiculum of interwoven
hyphe; conidia ovate or elliptic, very small.

Some forty species, chiefly American.

C. glumarum Miy. parasitizes rice in Japan."

496 THE FUNG! WHICH CAUSE PLANT DISEASE

Asteroma De Candolle (p. 482)

Pyecnidia very small, globose, erumpent, often on a mass of
hyphe; conidia ovate or short cylindric. In part =Gnomonia. See
p. 274.

About forty species chiefly parasitic.

A. padi (D. C.) Grev. on Prunus=Gnomonia padicola. See
p. 275.

A. geographicum (D. C.) Desm. occurs on various species of
Pomaceer;

A. punctiforme Berk. on the rose;

_ A. stuhimanni Hen. on bananas and pineapples in Africa.

A. codizei All. is said to be a serious parasite of Codieum.®

Vermicularia Fries (p. 482)

Pycnidia superficial, or erumpent, globose depressed, to globose
clavate, leathery or carbonous, black, ostiolate or not, beset
with rather long, stiff, septate, dark colored bristles; conidia
cylindric-fusoid, often curved.

Some one hundred thirty
species, chiefly saprophytes.

V. dematium (Pers.) Fr.

Pycnidia erumpent, superficial,
80-120 yu, conic, then depressed,
often confluent, black, spines
pale at the ends, 150-200 x 5 u;
conidia cylindric-elongate, 20 x
4-6 un, apically rounded, curved.
Fia. 341.—V. dematium. C, a nearly Commonly he saprophyte, this

Te phe ee a 8, spores; fungus occasionally causes as-

paragus disease.© In Europe it
is reported as the cause of much loss to the ginseng crop. On
this plant it produces a stem anthracnose. The fungus was
isolated and its cultural characters studied by Reed.*

V. trichella Fr.

Pycnidia ovate, small, black, spines long, at the apex of the
pycnidium; conidia fusoid, curved, pointed, 16-25 x 4-5 B

THE FUNGI WHICH CAUSE PLANT DISEASE 497

On living parts of many fruit hosts, as well as ivy and other
woody plants.?4

V. melice Fel. grows on Melica;

V. microcheta Pass. on camellia.

V. circinans Berk. ®

Spots orbicular; pycnidia arranged concentrically, small, sete
long; conidia oblong, curved, obtuse.

On onions the fungus appears as small black dots on the scales.
These later become encircled by rings of black pycnidia. Stone-
man found no true pycnidium; this would indicate relationship
of the organism with Volutella rather than with Vermicularia.

V. varians Duc. is described by Ducomet as the cause of a scab-
like disease of tomato and potato.

V. subeffigurata Schw. Pycnidia large, scattered, dark, sub+
elevated; spines unequal. On carnation leaves.

V. telephii Karst.

Pycnidia scattered, erumpent, superficial, spherical, dark, 100-
150 u; conidia fusoid bacilliform, acutely curved,
22-32 x 4 p.

On leaves and stems of cultivated Sedums.

V. concentrica Lev. is reported by Halsted *!
as causing unsightly spots on Draczna.

V. denudata Schw. A Vermicularia referred
to as probably this species is reported as dam- Win 0, eynend
aging to Kentucky blue grass in Dakota.” cheta berberidis,

V. polygoni-virginica Schw. is reported by pe oa TT
Reed & Cooley on rhubarb.™ deacher.

An undetermined species is reported as injurious to the potato.”

Pyrenocheta de Notaris (p. 482)

Pycnidia globose-clavate, erumpent, leathery or carbonous,
black, bristly, ostiolate; conidia ovate, elongate or cylindric;
conidiophores branched.

A genus of some thirty species.

P. phloxidis Mas. is common just above ground on living stems
of Phlox causing cankers.

P. ferox Sacc. is found on potato stems.

P. oryze Miyake” occurs on rice in Japan.

498 THE FUNGI WHICH CAUSE PLANT DISEASE

Fusicoccum Corda (p. 483)

Stroma subepidermal, several-chambered, erumpent, leathery,
black; conidia fusoid, straight and usually large.

Some forty species, several of which are regarded as conidial
forms of Diaporthe and Gnomonia.

F. veronense Massal on Sycamore and Oak=Gnomonia veneta.
See p. 274.

F. viticolum Red. on grape=Cryptosporella viticola. See p. 280.

Fic. 343.—F. viticolum, compound pyenidium, germinating spores, pa-
raphyses. After Reddick.

F. amygdali Del. causes a spot disease of almond twigs in
Europe.

F. bulgarium Bub. is described as the cause of a grape disease in
Austria.”?

F. perniciosum Briosi & Farm. on chestnut=Melanconis
modonia Tul. See p. 281.

Cytosporella Saccardo (p. 483)

Stroma tuberculate or cushion-form, immersed, then erumpent,
leathery, black, lighter within; conidia clavate or ovate, usually
quite small. Some twenty-five species.

THE FUNGI WHICH CAUSE PLANT DISEASE 499

C. cerei, Poll. is on Cereus;

C. citri Maynag. on oranges;

C. damnosa Pet. on pine; all in Italy.

C. persicz Schw. is reported on young peach branches.

Cytospora Ehrenberg (p. 483)

Stroma superficial or erumpent, tubercular, with irregular
chambers; conidia elongate allantoid.
Ascigerous forms belonging to Valsa are
known.

Some two hundred species, chiefly
saprophytes. wePgeeiaae et

C. palmarum Cke. is on palms. Fa. 4. —Cytospors,, Bee:

C. ceratophora Sacc. is the suspected tion through a stroma.

5 After Chester.
cause of a blight of Japanese chestnuts.”*

C. acerina Aderh. causes disease of Acer in Europe.”

C. sacchari Butler is found on sugar cane in Bengal.

Dothiorellina Bubak with the one species D. tankoffiii Bub. has
recently been described as the cause of disease of the mulberry.?”

Dothiorella Saccardo (p. 483)

Pycnidia erumpent, on a stroma, leathery, ostiole papillate or -
not; conidia‘ ovate or elongate.

Some seventy species, chiefly saprophytes.

D. ribis (Fcl.) Sacc., on a wide range of hosts=Diaporthe stru-
mella. See p. 279.

Fic. 345.—D. mori. N, section of stroma, 0, sonido.
phores and conidia. After Allescher.

D. mori Berl. and D. populi Sacc. are perhaps parasitic on Morus
and Populus respectively. ;
An unidentified species is reported by Duggar~ on currant as

the cause of cane blight. Inoculations using the conidia have
produced the disease. See also p. 283.

500 THE FUNGI WHICH CAUSE PLANT DISEASE

N

Fuckelia Bonordin (p. 483)

Stroma erumpent, globose-pulvinate, substipitate, dark without,
lighter within, with several angular pycnidial locules; conidia
elliptic.

A single species F. ribis Bon. on currants in Europe is a conidial
form of Cenangium vitesia. See p..151.

Ceuthospora Grevielle (p. 483)

Stroma coalescing, erumpent, cushion-shaped, leathery, many-
chambered, all chambers opening by a common pore; conidia
elongate cylindric, mostly straight.

Some twenty-five species, chiefly saprophytes.

"2

: Fic. 347.—Plagiorhabdus
pycnidium. After oxycocci on cranberry.

Delacroix. After Shear.

C. coffeicola Del. is of questionable parasitism on coffee;

C.-cattleyz Sacc. & Syd. on orchids.

Plagiorhabdus oxycocci Shear has been reported on cran-
berry.”

Sphezrioidacee—Pheospore (p. 480)
Conidia 1-celled, dark, globose, ovoid or oblong.

Key to Genera or Spheropsioidacee—Pheospore

Pycnidia separate
Pycnidia without mycelium or subicle
Pycnidia smooth, not hairy
Conidia in chains, globose... ...... 1. Sirothecium.

THE FUNGI WHICH CAUSE PLANT DISEASE 501

Conidia not in chains
Pycnidia sessile, spheroid
Pycnidia beaked.............. 2. Nemosphera.
Pycnidia not beaked
Conidia spindle-form, with
both ends light colored.. 3. Hypocenia.
Conidia globose to elliptic
Pycnidia opening irregu-

Latly saree hen wataeinacs 4. Harknessia.
Pyenidia opening by a regu-
lar ostiole
Conidia large, ovate to
elliptic. ........... 5. Spheropsis, p. 501.
Conidia very small, glo-
bose to ellipsoid.... 6. Coniothyrium, p. 503.
Pycnidia stipitate, clavate. ...... 7. Levieuxia.
Pycnidia hairy or setose............. 8. Chetomella.
Pycnidia with distinct mycelium or
subicle
Pycnidia astomous, in a dark subicle.. 9. Capnodiastrum.
Pycnidia perforate................... 10. Cicinnobella.
Pycnidia cespitose or in a stroma
Pycnidia in dense erumpent clusters..... 11. Haplosporella.
Pycnidia not as above, in a definite
stroma

Stroma applanate or effuse, foliicolous. 12. Discomycopsis.
Stroma dot-like, discoid or hemi-

spheric
Stroma dot-like, immersed......... 13. Melanconiopsis.
Stroma discoid to hemispheric
Stroma discoid; spores large. .... . 14. Nothopatella.
Stroma pulvinate; spores minute,
catenulate ................ 15. Cytoplea.
Stroma hemispheric; pycnidia
circinate. ................-. 16: Weinmannodora.

Spheropsis Léveillé

Pycnidia immersed, erumpent, globoid, black, leathery, mem-
branous, with the ostiole papillate; conidia ovate or elongate,
conidiophores rod-like.

502 THE FUNGI WHICH CAUSE PLANT DISEASE

About two hundred species several of them important plant
pathogens.

S. malorum Pk. % 7 77-8

Mycelium sooty-brown; pycnidia erumpent, usually surrounded
by broken epidermis, apically somewhat depressed; conidia oblong
elliptic, brown, usually about twice as long as broad, 22-32 x 10-14
, varying in size with host and part attacked.

On apple, pear, quince, hawthorn; on twigs causing canker or
blight; on fruit causing rot and on leaves causing spots.

Fic. 348.—S. malorum, 6, dark colored mycelial
threads among the cells of the fruit; d, a
pycnidium, which has pushed through the epi-
dermis, c, and is giving off dark colored spores, e;
B, mature spores germinating in water. After
Longyear.

This is one of the common causes of pomaceous fruit rots and
of leaf spot in the United States. Its occurrence in leaf spots was
noted in 1898,” and in 1902 Clinton © recognized it as their cause.
Cultures were obtained from diseased leaf spots by Scott & Rorer
and by inoculations the ability of the fungus to cause spots was
definitely proved.

This fungus was reported by Paddock * as the probable cause
of apple twig blight and canker and cross inoculation between
twigs and fruit proved the identity of the fungus on these two parts.

The mycelium is very dark or olivaceous and abounds in the
rotten pulp of affected fruit, also in diseased bark, and is even

THE FUNGI WHICH CAUSE PLANT DISEASE 503

present in wood though extending but sparingly into woody
tissue.

A pycnidial fungus agreeing with S. malorum morphologically
has been shown by Shear ® to be a conidial form of the ascigerous
fungus Melanops (=Botryospheria), see p. 284.

S. pseudodiplodia (Man.) G. & M. ** *4 causes an apple disease
in Europe.

S. mori Berl. parasitizes Morus;

S. ulmi 8. & R. the elm;

S. magnoliz Magnag. the Magnolia in Italy;

§. japonicum Miy. rice in Japan."

S. vince 8. & W.

Pycnidia gregarious or scattered, globose, immersed, black,
small, 260-300 u; ostiole papillate, erumpent; conidia ovate,
ovate-oblong or subpyriform, 17-28 x 10-14 ». On Vinca."4

Many other forms are recorded on various hosts but their
parasitism is questionable.

Coniothyrium Corda (p. 501)

Pycnidia subcortical, erumpent or not, globose or depressed,
ostiole papillate, black, leathery to carbonous; spores small,
ellipsoid, conidiophore reduced or absent.

More than one hundred fifty species.

C. pyriana (Sacc.) Shel. is common on apple leaf spots but is not
regarded as their cause.’

C. concentricum (Desm.) Sacc. occurs on Yucca, Dracena, etc.

C. tumefaciens Gus.®° is described as the cause of a rose canker.

C. melastorum (Berk.) Sacc.® is on sugar cane.

C. fuckelii Sacc.®”

Pycnidia superficial, scattered, dark, 180-200 n, globose-
depressed; conidia numerous, globose to short-elliptic, 2.4-5 x
2-3.5 py.

The European form is reported on dead and dying branches and
a form closely allied to it, probably identical, has been studied in
New York as the cause of a raspberry cane-blight. This fungus
and no other was present and typical disease followed inoculation.
The organism was recovered in pure culture. Both new and old
canes died within two months after inoculation.

004 THE FUNGI WHICH CAUSE PLANT DISEASE

This is a conidial form of Leptospheria coniothyrium. See
pr20%e

The same fungus was reported by Stevens & Hall *® and was
studied by O’Gara*® and determined by inoculation and cross
inoculating, using pure cultures, to be the cause of rose and apple
canker and apple fruit rot.

C. diplodiella (Speg.) Sacc.*#

Pycnidia minute, subcuticular, erumpent, brown, 100-150 yg;
conidia ovoid to elliptic, 7-11 x 5.5 uw; conidiophores simple or
branched, hyaline, filiform.

This is the cause of a white rot of grapes and has been reported

Fig. 349.—C. diplodiella, section through
pycnidium. After Scribner.

by Viali & Ravez as belonging to the ascigerous genus Carrinia.”
See p. 263.

Though probably of American origin it was first recognized
in Italy in 1878. In 1887 it caused alarm in France and it was
first noted in America in the same year. The mycelium is abundant
in the affected pulp and sometimes upon the seeds. Peduncles
are often killed. The pycnidia are subcuticular, first pink, then
white, later brown.

C. scabrum McA. is the cause of black scurf of citrous fruit
in Australia.

C. coffez Zimm. is on coffee in Java.

C. vagabundum Sacc. causes premature fall of leaves of goose-
berries.

C. japonicum Miy., C. brevisporum Miy. and C. anomale
Miy. are found on rice in Japan."

THE FUNGI WHICH CAUSE PLANT DISEASE 505

C. wernsdorffie Kock occurs on roses.
C. hellebori C. & M. is found on hellebore.

Sphzrioidacee—Hyalodidyme (p. 480)

Conidia hyaline, 1-septate, ovoid, ellipsoid or oblong.

Key to Genrra or Spherioidacee—Hyalodidyme

Pycnidia separate
Pycnidia not beaked
Pyenidia in discolored areas, maculicole
Pycnidia immersed, then erumpent,

perforate
Conidia muticate. .............. 1. Ascochyta, p. 506.
Conidia with setz at the apex.... 2. Robillarda.
Pyenidia superficial, astomous. ..... 3. Pucciniospora.
Pycnidia not maculicole
Pyenidia hairy. .................- 4. Didymocheata.

Pycniilia smooth
Conidia with an appendage at each
end
Conidia with 1 or more bristles. 5. Darluca.
Conidia with cap-like append-
BEES. < ea sede we reeee we 6. Tiarospora.

Conidia muticate

Conidiophores 1-spored

Pycnidia without subicle..... 7. Diplodina, p. 509.
Pycnidia on a cobwebby subi-
cle, phyllogenous........ 8. Actinonema, p. 508
Conidiophores several to many-
SPOTEd scan. cesasees whem 9. Cystotricha.
Pyenidia beaked. .........-..-.----- 10. Rhynchophoma.

Pycnidia in a stroma
Stroma effuse
Stroma consisting of two distinct

layerss ua 2 deere vakede seen 11. Thoracella.
Stroma of a single layer..........-. 12. Placospherella.
Stroma verruciform
Stroma superficial... ..........-.- 13. Patzschkeella.

Stroma erumpent...............-- 14, Cytodiplospora.

506 THE FUNGI WHICH CAUSE PLANT DISEASE !

Ascochyta Libert (p. 505)

Usually producing definite spots; pycnidia globose-lenticular,
ostiolate; conidia ovate. 7
About two hundred fifty species.
A. pisi Lib.?" °» 92=Mycosphzrella pinodes.*“” See p. 250.
Spots variable in size, roundish, yellowish with brown margin;
pycnidia centrally located, black, of angular cells, 5-7 y; ostiole
rounded,’ surface reddish brown; conidia

od slightly constricted at the septum, oblong,
12-16 x 4-6 yw; exuded spore-mass brown.

4 On peas, beans, vetch, Cercis, etc. The

’ pycnidia are visible on the dead areas of the

stems, leaves, pods or seesls. The mycelium
hibernates in affected seeds, reduces their
6 ; germinating power and. carries the fungus
H A over to the succeeding crop.
Fic. 350.— A. citri, A+ bottshauseri Sacc. on bean in Swit-

a eee zerland % is closely related to the last

species. ‘

A. armoracie Fel. is on horse radish, causing leaf spots;

A. ellisii Thiim. on grape;

A. brassice Thiim. on cabbage, forming large dull patches;
often quite injurious.

A. rhei E. & E.

Spores finally constricted and 1-septate, 7-12 x 3.5-4 u, hyaline.

On rhubarb.

A. viciz Lib.

Epiphyllous; spots roundish, reddish, margin elevated, orange
red; pycnidia minute, clustered, black, 90-100 4; conidia
oblong-ovate, obtuse, slightly constricted, 12-15 x 4-5 yu; exuded
mass white. On Vicia.

A. nicotiane Pass.*4

Spots between the veins, irregularly scattered, brown; conidia
oblong ovate, constricted at the septum. On tobacco.

A. parasitica Faut.

Spots whitish; epiphyllous; pycnidia small, black, Conidia el-
liptic, 3-4 x 6-10 .

THE FUNGI WHICH CAUSE PLANT DISEASE 507

This is fqund associated with rust sori on malvaceous hosts.1”' %
A. polem®nii Br. & Cav. occurs on Polemonium.

- piniperda Lin. is parasitic on fir leaves.

. aquilegiz Roum. spots columbine leaves.

. beticola P. & D. is on beet leaves;

orobi Sacc. on sainfoin; and A. oryz@ Catt. on rice in Italy.
. lactucze Rost. is on lettuce;

esculi Bub. & Kab. on Aisculus in Europe;

pallida Bub. & Kab. on ‘Acer in Europe;

pruni Bub. & Kab. on the cherry in Europe;

populicola Bub. & Kab. on the Silver Poplar in Europe;
dianthi Berk. on Dianthus and other pinks;

viole Sacc. causing spots on violet leaves;

. digitalis Fcl. on digitalis;

. iridis Oud. on Iris.

. juglandis Bolt. causes spots on leaves of Juglans; %

. aspidistre Mas. on Aspidistra.

. fragariz Sacc.

Perithecia partly immersed, black, 100-125 yu; conidia fusiform
to cylindric, constricted, 14-27 x 4-5.5 yp.

This was reported by Dudley as occurring in injurious form
near Rochester, N. Y., causing spots, at first red, later brown,
on strawberry leaves.

A. primule Wail.”

Epiphyllous; pycnidia on discolored spots, scattered, depressed
globose, 100-110 y, pale brown, papillate ostiolate; conidia cy-
lindric, obtuse, 5-6 x 2-2.5 ». On Primula.

A. chrysanthemi Stev.%

Pycnidia few, immersed, early erumpent, single or scattered,
hemispheric, amber-colored, 100-200 u; ostiole central, small,
often raised by a neck, dark-bordered; conidia oblong, straight
or irregular, 3-6.2 x 10-20 uy, apically obtuse, septum often ob-
scure, sometimes more than one; not constricted till germination.

It causes blighting of ray flowers of chrysanthemums.

A. medicaginis Bres.

Spots small, angular, pale, clustered; pycnidia sublenticular,
apiculate, pale, becoming black, 200 x 160 u, context parenchy-
matous; conidia oblong, obtuse, scarcely constricted, 10-12 x 4-

>>> >>> >>> > >> > > > >

508 THE FUNGI WHICH CAUSE PLANT DISEASE

4.5 u. According to Stewart, French & Wilson, spots are caused
on alfalfa. The American form is distinct from the European
and has been described under the name A. imperfecta Pk.**

A. lycopersici Brum.

Spots red or brown, large, rounded or irregular; pycnidia sparse,
minute, black; conidia oblong, constructed, 8-10 x 2.5 u.

Spots are produced on leaves and fruits of egg plant.

A. caulicola Lau. causes injury to Melilotus alba.”

A. cookei Mas. is reported on Sweet William.

A. corticola McA. is the cause of lemon bark-blotch in Australia,
killing the trees.!01

A. graminicola Sacc. occurs on grasses and grains;

Fig. 3:

-

A. manihotes Hen. on cassava in Africa.
A. tremule Sacc. occurs on aspen;
A. melutispora B. & Br. on ash.

Actinonema Fries (p. 505)

Pyenidia very small, not ostiolate, with a radiating mycelial
growth on the surface of the host; conidia elongate, on short
conidiophores.

A genus of about fifteen species, chiefly leaf parasites.

A. rose (Lib.) Fr. 444

Spots rounded or irregular, black or purple, epiphyllous, often

THE FUNGI WHICH CAUSE PLANT DISEASE 509

confluent, marginally fimbriate, the radiating fibers arachnoid,
white, distinctly branched; pycnidia tuberculariform, scattered
or confluent, black; conidia oblong, constricted, 18-20 x 5. yu;
conidiophores short.

This fungus was first described in 1826. It is common on rose
leaves. The mycelium is in part subcuticular, in part deeper.
The subcuticular part is visible through the cuticle, consisting
of radiate strands each composed of several parallel hyphe. From
this mycelium branches penetrate deep into the leaf. The dark
color of the leaf spots is due to discoloration of the contents of the
diseased cells; the mycelium itself having little or no color.

A. tiliz All. causes defoliation of Tilia.

A. fagicola All. occurs on beech leaves;

A. fraxani All. on ash. ;

Diplodina Westendorp (p. 505)

Pycnidia immersed or erumpent, globose; ostiole papillate,
black, small; spores elongate.
It differs from Diplodia only
in the hyaline spores.

About eighty species chiefly
saprophytes.

D. citrullina (C. O. Sm.)
Gres. on cucurbs=Mycosphe- <“AP45
rella cirullina. See p. 246.

D. castanee P. & D. in-
jures chestnut leaves, and
causes cankers on the shoots in France, resulting in serious
loss. 10?

D. parasitica (Hart.) Prill. occurs on the basal leaves of young:
shoots of spruce causing defoliation.

D. salicina C. & M. causes tips of willows to die.

D. corticola A. & 8. is found on cacao in Africa.

Spherioidacee-Phzodidyme (p. 480)

Conidia dark, 1-septate, ovoid to oblong.

510 THE FUNGI WHICH CAUSE PLANT DISEASE

Key to Spherioidaceer-Pheodidyme

Pycnidia separate

Pyenidia beaked
Pyenidia hairy...........--.-. 1. Rhynchodiplodia, p. 510.
Pycnidia smooth...........+--+- 2. Pellioniella.
Pyenidia not beaked
Pyenidia hairy. .............+4- 3. Chetodiplodia, p. 510.
Pycnidia smooth
Conidia with a mucous laycr,
very large............... 4. Macrodiplodia.

Conidia without a mucous layer
Pyenidia erumpent, conidia
muticate

Conidia less than 15 v long.

Conidia 15 w or more long.

Pyenidia superficial, lignicole.

Pycnidia cespitose or in a stroma

Pyenidia cespitose. .............-- 8. Botryodiplodia, p. 513.

Pycnidia in a stroma
Pyenidia and subicle enclosed in a

. Microdiplodia, p. 510.
. Diplodia, p. 511.
. Diplodiella, p. 512.

ND ot

hemispheric stroma. ........ 9. Lasiodiplodia, p. 513.
Pycnidia without subicle, in a
globose stroma.............. 10. Diplodiopsis.

Rhynchodiplodia Briosi & Farneti

Pycnidia rostrate, pilose; conidia oblong.
A single species, R. citri B. & F., causes disease of the lemon.

Chetodiplodia Karsten

Pycnidia erumpent, globose, ostiolate, black, membrano-
carbonous, hairy or bristiy; conidia elongate.

A genus of about ten species, chiefly saprophytes.

C. vanillz Zimm. is on vanilla.

Microdiplodia Allescher

Pyenidia subcuticular, erumpent, membranous to subcarbon-
ous, globose or depressed, minutely ostiolate; conidia ovoid to
oblong, small, (under 15 u.)

THE FUNGI WHICH CAUSE PLANT DISEASE 511

More than twenty-five species, chiefly saprophytes.
M. anthurii Trinch. occurs on Anthurium.

Diplodia Fries (p. 510)

Pyenidia immersed, erumpent, carbonous, black, usually
ostiolate-papillate; conidia ellipsoid or ovate; conidiophores
needle-shaped, simple, hyaline.

Over four hundred fifty species, many of them saprophytes.

D. zez (Schw.) Lev.109-105

On ears and stalks of corn, pycnidia borne on the husks, cobs,
stalks and rarely the grains, gregarious, small, lenticular to flask-
shaped or irregular, papillate; conidia elliptic, straight or curved,
constricted or not, 25-30 x 6 y.

It occurs as the cause of a very serious dry rot of ear corn.

The actual growing mycelium is hyaline and much branched.

Pycnidia in the cob are principally on the scales which surround
the inner ends of the kernels and are set in a dense mass of white
mycelium. On dead stalks
the pycnidia form below
the rind, particularly at
the nodes, breaking
through during the follow- &
ing summer, and extruding
the spores in cirri.

The fungus was studied 29%
extensively by Burrill &
Barrett °° and inoculations 2
were made using pure cul- 71.888 > Pyeidinof Died or ke
tures. Spores placed under
the husk or in the silk, or sprayed upon plants in suspensions, re-
sulted in disease.

Smith and Hedges report that infection is often by way of the
root system, the mycelium reaching the grains through the stem
and from the cob.

D. macrospora Ea.

Pycnidia scattered, large, erumpent, carbonous; conidia elon-
gate, irregularly clavate, curved or constricted, 70-80 x 6-8 u.

512 THE FUNGI WHICH CAUSE PLANT DISEASE ,

This is responsible for a corn mold similar to that caused by
the last species.

Other parasitic species are:

. oryze Miy. on rice;

. cerasorum F'cl. on cherries;

- aurantii Catt. on oranges;

. mori West. on Morus;

. gongrogena Temme on Populus in Germany;

. sapinea (Fr.) Fel. on conifers;

. pinea Kick. on pine leaves in Europe; 2

. coffeicola Zimm. on coffee;

. perseana Del. on the avocado.

opuntie Sacc. is sometimes a serious pest of the cactus.
. citricola McA. occurs in Australia on lemon twigs, stems
and green fruit. ‘

D. destruens McA. is on orange and lemon leaves in Australia; ™

D. heteroclita D. & M. on Citrus in Algiers.1

D. cacaoicola Hen. does much injury to cacao and sugar
cane in the West Indies.

D. natalensis Ev. causes a serious black rot of citrus fruits in the
Transvaal; 1

Pycnidia scattered, covered, later erumpent, black; papillate
150-180 u; spores elliptical, 1-septate, not constricted, dark, 24
x 15 yw, exospore with striated bands.

A Diplodia which cannot be distinguished from this was studied
by Fawcett and Burger and is reported as the cause of gum-
mosis of peach and orange in Florida.”” Pure culture inoculations
and cross inoculation showed the same fungus able to cause the
disease on both hosts.

D. rapax Mas. is the cause of a stem disease of Para rubber.™

D. epicocos Cke. grows on the coconut and an undetermined
species attacks ripe pineapples.™

SE-B R-R~R-B-E-- EB

Diplodiella Karsten (p. 510)

Pyenidia superficial, globose, ostiolate papillate, black, smooth,
rather carbonous; conidia elliptic.
About twenty-five species, chiefly saprophytes on wood.
-D. oryze Miy. is found on rice.*®

THE FUNGI WHICH CAUSE PLANT DISEASE 513

Botryodiplodia Saccardo (p. 510)

’

Pycnidia botryose-confluent, erumpent, stromatic, membrano-
carbonous, black, usually ostiolate-papillate; conidia elongate or
ovate.

Over thirty species, chiefly saprophytes.

An unnamed species of this genus is given by Butler as the
probable cause of a coconut palm disease in India.

Lasiodiplodia Ellis & Everhart (p. 510)

Pycnidia collected on a stroma,
covered with a brown mycelium, paraph-
yses among the conidiophores. Other-
wise as in Diplodia.

Two species, both parasites.

L. tubericola E. & I.1

Pycnidia globose, 250-305 u; stro-
matic mass about 1 mm. in diameter; co-
nidia elliptic, 18-22 x 11-14 y, not con-
stricted; conidiophores short; paraph-

yses 45-55 yw long, overtopping the

conidia. Fic. 354.—Lasiodiplodia tu-
bericola. Perithecium, pa-
It was found on sweet potatoes from _raphyses and spores. After

Java which were brought to the Clendenin.
Louisiana Experiment Station in 1894.
L. theobromz (Pat.) G. & M. is a wound parasite of Hevea.

Sphezrioidacee-Hyalophragmiz (p. 480)

Conidia hyaline, 2 to many-septate, oblong to fusoid.

Key To Genera or Spherioidacee-Hyalophragmie

Pycnidia more or less globose
Subicle none
Conidia appendaged at apex
Sete Dies hiennevny Ad erawate 1. Kellermania.
Lo fo ee Nara ee 2. Bartalinia.

514 THE FUNGI WHICH CAUSE PLANT DISEASE

Conidia muticate. ................-- 3. Stagonospora, p. 514.
Subicle present, dark, phyllogenous. .... 4. Asterostomidium.
Pycnidia elongate to cylindric............ 5. Mastomyces, p. 514.

Stagonospora Saccardo

Pyenidia superficial or erumpent,
globose, ostiolate-papillate, black,
membranous or subcarbonous; co-
nidia elongate, 3 or more-celled.

Over one hundred species, chiefly
saprophytes; differing from Hen-
dersonia only in the hyaline conidia.

S. carpathica Beeuml.

Spots circular, 1-3 mm., light
z brown with a narrow darker border;
Fic. 355.—Stagonospora. C, pyc- pee sigs es

nidium_ in section. D, spores. pycnidia 120-180 py; conidia escaping

After Corda. in a gelatinous mass, straight or
slightly curved, 14-28 x 4 uw, 2 to 5-celled, frequently slightly
constricted. It causes leaf spots on alfalfa.

S. iridis Mass. occurs on iris.

Mastomyces Mont.

Pyenidia gregarious, separate, erumpent, elongate, papillate-
ostiolate; conidia fusiform, 3-septate.

There are two species, one of which, M. friesii Mont., is
probably the conidial form of Scleroderris ribesia, see p. 155, the
cause of a relatively unimportant currant disease of Europe.

Sphzrioidaceex-Phzophragmiz (p. 480)

Conidia hyaline, 2 to several-septate, oblong to fusoid.

Key to Genera or Spherioidacez-Phzophragmie

Pycnidia separate
Pycnidia not beaked
Conidia free from each other
Conidia muticate
Pycnidia papillate or subastomous
Pycnidia with flattened base..... 1. Macrobatis.

THE FUNGI WHICH CAUSE PLANT DISEASE 515

Pycnidia globose, without flat-
tened base but on a stellate
superficial subicle......... 2. Couturea.
Pycnidia without a subicle,
erumpent
Pyenidia hairy............. 3. Wojnowicia.
Pyenidia smooth............ 4. Hendersonia, p. 515.
Pycnidia opening widely, with an
operculum
Pyenidia superficial, dark, hairy 5. Angiopoma.
Pycnidia immersed, pale,smooth 6. Lichenopsis.

Conidia appendaged
Conidia 1-ciliate at each end..... 7. Cryptostictis, p. 516.
Conidia 1-ciliate at base......... 8. Urohendersonia.
Conidia with a round or cup-like

appendage at cach end. ..... 9. Santiella.
Conidia united in groups
Conidia united into a fascicle....... 10. Eriosporina.
Conidia stellately united........... 11. Prosthemium.
Pyenidia beaked. .................00055 12. Pseudographium.
Pycnidia in a stroma.................00. 13. Hendersonula, p. 516.

Hendersonia Berkley

Pycnidia immersed, erumpent or not,
globose with a papillate ostiole or depressed,
membranous or subcarbonous; conidia elon-
gate or fusoid, 2 to many-septate.

Some two hundred fifty species, chiefly
saprophytic, although there are several para-
sitic species.

H. mali Thim. ne

Epiphyllous; pycnidia disciform, large, se cy ie ee : ae i
scattered, black, on brownish, orbicular, and spores. After
violet-margined spots; conidia clavate, apex St#rback.
rounded, base somewhat acute, not constricted, 12-14 x 4-5 u.

On leaves of apple in Europe and America.

H. piricola Sacc. is on pear; H. cydonz C. & E. on quince;

H. acicola M. & T. causes a pine leaf disease.1!!

H. coffez Del. is on coffee;

516 THE FUNGI WHICH CAUSE PLANT DISEASE

H. oryzz Miy. on rice;

H. notha Sacc. & Br. on Juniperus leaves;

H. togniniana Poll. on Cycas.

H. foliicola (Berk.) Fel.*°°

Pycnidia epiphyllous, brownish-black, subglobose, subelliptic
or irregular; conidia elliptic to clavate, obtuse, 3 to 5-septate; conid-
iophores filiform, radiating. On Juniperus and Pine.

Cryptostictis Fuckel (p. 515)

Pycnidia erumpent, globose or depressed,
ostiolate; conidia elongate, 2 or more septate,
subapically appendiculate with a long hyaline
bristle. It differs from Hendersonia chiefly in
spore characters. ;

A small genus of eleven species. chiefly sapro-
Fia. 357.—Cryptos- phytes.

tictis, spores. Af- — C. cynosbati (Fel.) Sacc. and

C. caudata (Preu.) Sacc. occur on the rose,
the former on the fruit and branches forming wounds.

Hendersonula Speg. (p. 515)

Stroma black, irregular; ostioles punctiform; spores ellipsoid,
several-celled, colored.. In part =Plowrightia.
A form on the plum=Plowrightia morbosa. See p. 218.

Spherioidacee-Pheodictyz (p. 480)
Conidia dark, muriform, oblong to ovoid, rarely radiate or

cruciate.

Key To Genera oF Spherioidacee-Pheodictye

Pyenidia separate
Conidia not reticulate

Pycnidia on bark, erumpent........ 1. Camarosporiun, p. 517.
Pycnidia on wood, superficial... .... 2. Cytosporium.
Conidia reticulate..............0.... 3. Endobotrya.

Pycnidia merely locules ina stroma..... 4. Dichomera.

THE FUNGI WHICH CAUSE PLANT DISEASE 517

Camarosporium Schulzer von Miggenburg (p. 516)

_ Pyenidia immersed, erumpent, separate,
globose, ostiolate, papillate, carbonous or
submembranous; conidia ovate to fusiform,
muriform, with 2 to many cross walls.

Over one hundred twenty species, chiefly
saprophytes. ,

C. fissum (Pers.) Star. causes injury to
roses.

C. viticola (Cke. & H.) Sacce. is reported on
grape; Fie. 358.-— Camaro-

C. mori Sacc. on Morus. ya ae Heo aca

Spherioidacez-Scolecospore (p. 480)

Conidia hyaline or light colored, elongate-fusoid, rod-shaped
or filiform, continuous or septate.

Key to Genera oF Spherioidacese-Scolecospore

Pycnidia separate
Pycnidia membranous or carbonous
Pycnidia superficial
Pycnidia hairy
Conidia single on the conidiophores 1. Trichocollonema.
Conidia ternate on the conidio-

Phorese 450g 5 sie eevee aia s 2. Gamospora.
Pycnidia smooth
Pyenidia beaked. ............... 3. Cornularia.
Pycnidia not beaked

Conidia usually expelled in aball 4. Collonema.
Conidia not expelled in a ball.. 5. Septorella.
ycnidia immersed or erumpent
Pyenidia hairy, maculicole......... 6. Trichoseptoria, p. 518.
Pycnidia smooth ,
Pyenidia beaked .............. 7. Spherographium.
Pyenidia not beaked
Pyenidia maculicole, mainly
phyllogenous
Conidia hyaline............ 8. Septoria, p. 518.
Conidia colored............. 9. Pheoseptoria, p. 525.

518 THE FUNGI WHICH CAUSE PLANT DISEASE

Pyenidia not maculicole
Pyenidia complete at top,
usually papillate. ....... 10. Rhabdospora, p. 525.
Pycnidia more or less incom-
plete at top
Pycnidia gaping, showing a
gelatinous spore mass. 11. Gelatinosporium.
Pyenidia not exposing a ge-
latinous mass
Pyenidia foliicole. ...... 12. Phleospora, p. 525.
Pycnidia rami-caulicole.. 13. Phlyctena.
Pyenidia suberose, incomplete, often pale
Pyenidia cespitose. ............0006 14. Micropera.
Pycnidia merely gregarious. ......... 15. Micula.
Pycnidia in a stroma
Conidia 4 to 6-fasciculate on a conidio-

photes:s. 2 susisies ews ones sense esas 16. Eriospora.
Conidia separate
Conidia setose-penicillate. ........... 17. Dilophospora, p. 525.
Conidia muticate
Stroma superficial, setose. ......... 18. Septodothideopsis.

Stroma erumpent or immersed _
Pycnidia distinct in the stroma,

conidia hyaline............. 19. Cytosporina, p. 526.
Pycnidia as locules in the stroma,
conidia colored............. 20. Septosporiella.

Trichoseptoria Cavara (p. 517)

Pycnidia separate, erumpent, on spots, membranous, hairy;
conidia needle-shaped, septate.

A single species. T. alpei Cav."!? is reported by Cavara as
injurious to lemon fruits in Italy.

Septoria Fries (p. 517)

Pycnidia immersed, usually on leaf spots, globose lenticular,
ostiolate, membranous, black; conidia narrowly elongate to fili-
form, multiseptate, hyaline, conidiophores very short.

Over nine hundred species, all parasitic, several of them of
considerable economic importance but most of them occurring on
non-economic hosts.

THE FUNGI WHICH CAUSE PLANT DISEASE 519

In part=Mycospherella, Leptospheeria.

The genus is a very large one similar to Phoma and Phyllosticta
except in its spore form and in the ostiole which is frequently
very large. Septoria and Phleospora are distinguished only by
the lesser development of the walls of the latter and many species
which in early stages pass as Phleospora would in older stages be
classed as Septoria.

Septoria and Rhabdospora are distinguished only by the part
of the host affected, stem or leaf, and many forms in these two
genera are undoubtedly identical.

S. pisi West. is on peas.

S. piricola Desm. on pear and apple=Mycospherella sentina.
See p. 246.

S. populi Desm. on Populus=Mycospherella populi. See p. 250.

S. phlogis Sacc. & Speg. on Phlox=Leptospheria phlogis. See
p. 258.

S. ribis Desm.1%

Hypophyllous; spots small, irregular, bounded by the leaf veins,
brownish-purple; pycnidia in-
nate, minute, convex, brownish-
black; cirri in mass reddish; co-
nidia elongate, linear, curved,
50 uw long.

On gooseberry and currant,
causing leaf spots and defolia-
tion.

S. aciculosa E. & E.

Pycnidia innate to superficial,
grouped, minute, amphigenous; conidia needle-shaped, continuous,
15-20 x 0.75 yp.

It is found on the strawberry.

S. fragariz Desm.

Epiphyllous; spots suborbicular, brown, with reddish-brown
margin; pycnidia minute, innate, prominent, brownish; cirri white;
conidia cylindric, obtuse, 3-septate.

Perhaps =Mycospherella fragarie. See p. 244.

On strawberry, cultivated and wild, forming circular leaf
spots.

spores. After Longyear.

520 THE FUNGI WHICH CAUSE PLANT DISEASE

S. cerasina Pk.14

Spots scattered or confluent, minute, subangular, brown or
reddish-brown; pycnidia pale, collapsing; conidia filiform, straight
or curved, 50-75 » long. On cherry.

S. pruni E.15

Spots dark brown, dry, subrotund, soon breaking out, 1-3 mm.;
pycnidia brown, immersed, 60 u; conidia linear, obtuse, 4 to
6-septate, 30-50 x 2 uw. On plum.

S. limonum Pass. and S. sicula Penz, occur on citrus;

S. glaucescens Trab. on the mandarin;

S. loefgreni N. on oranges in Brazil;

S. ampelina B. & C. on the grape.

S. longispora Sh. (not Miy.) is found on the cranberry.!”

S. graminum Desm.U018

Spots slightly elongate, pale, fuscous-margined, limited by the
leaf veins; pycnidia seriate or scattered, brownish; conidia very
slender, straight or curved, non-septate, but multiguttulate,
55-75 x 1-1.3 yp.

This is a frequent saprophyte or weak parasite on wheat, oats
and numerous wild grasses. Under some conditions it becomes
an injurious parasite, especially upon winter wheat.

S. tritici Desm. is closely like S. graminum.""*

It is associated with Leptospheria tritici on wheat. See
p. 258.

S. glumarum Pass. is also found on wheat.

S. nodorum Berk. occurs, particularly at the nodes, on the same
host.

S. secalina Jancz. is on wheat and rye leaf sheaths;

S. avene Frank. on leaves of oat.

S. longispora Miy. (not Shear) and S. curvula Miy. are on
rice.

S. bete West.

Spots pale brown, white in the center, brownish-margined;
pycnidia epiphyllous, minute, black, prominent; conidia cylindric,
straight or curved, white in mass.

It was noted by Humphrey ™® causing a beet leaf spot.

S. citrulli E. & E. :

Spots small, round, white, scattered; pycnidia mostly solitary,

THE "FUNGI WHICH CAUSE PLANT DISEASE 521

one in the center of each spot, but slightly prominent; conidia
cylindric or clavate-cylindric, 10-25 x 1.5-2 p.

On watermelon leaves.

S. cucurbitacearum Sace. is also on cucurbits. !”

S. cannabina Pk. is on hemp producing leaf spots.

S. nicotiane Pat. is reported from France as the cause of tobacco
leaf spotting.!”°

S. dolichi B. & C.

Spots white, with a broad, light brown margin; conidia straight,
subfusiform, 3-septate, 40 u. On cowpeas.}2

S. medicaginis Rob. & Desm. is on alfalfa.

Spots whitish, angulate-subcircular, confluent ; pycnidia len-
ticular, 70-90 4; conidia slender, vermiform, tortuous, 60-70 x 1 B,
septate.

S. petroselini Desm.

Spots brown, in age white, amphigenous; pycnidia epiphyllous,
minute, olivaceous, promi-
nent; conidia filiform, straight
or curved, 35-40 x 1-2». On
parsley.

S. petroselini apii Br. &
Cav.25 122-126

This common and very de-
structive fungus on celery
leaves was first described in
Italy by Cavara and in
America it was early noted
by Chester }2? and Halsted.?°
The pycnidia are abundant in 5, 369. petroselini api. Pyenidium
the leaf spots and in the case showing spores oozing through the ostiole.

After Jensen.
of stored celery they are
found scattered over the blanched petioles. Essentially it is only
a host variety.

S. lycopersici Speg.2” 12% 1%

Spots large, often confluent and covering the entire leaf, sordid
cinereous, subindeterminate; pycnidia scattered, hypophyllous,
lenticular-bemispheric, prominent, membranous; conidia elongate,
cylindric, 70-110 x 3.3 y», pluriseptate.

522 THE FUNGI WHICH CAUSE PLANT DISEASE .
The cause of leaf spots of tomato. It was noted in New Jersey
about 18932” and in Ohio in 1896.!% It is one of the serious
tomato pests.
S. lactucze Pass.**°
Spots irregular, brownish, angulate, sometimes destroying the
entire leaf, pycnidia minute, punctiform, scattered, 90 » in
diameter, conidia filiform, straight or curved, 25-
30 x 1.7-2 yu.

On lettuce.
S. consimilis E. & M.*

Distinguishable from the preceding by the more
<r indefinite spots, slightly larger pycnidia (90-100 #)
and longer conidia (80-45 x 2-2.5 »). It causes
brown spots on lettuce leaves.
Fra. 361.—Spores 5» atmoraciae Sacc.”
a - a Spots irregular, ochraceous; pycnidia puncti-
er Reed. Z
form, grouped in the center of the spot, 60 x;
conidia filiform, curved, 15-20 x 2-2.5 u, 1 to 3-septate. On
horseradish causing leaf spot.

S. antirrhini Desm. attacks the snapdragon severely.!”

S. rosz2 Desm. is on rose;

S. hydrangee Bizz. on cultivated hydrangea;

S. iridis C. Mass. on Iris.

S. cyclaminis Dur. & M. on cyclamen.

S. sedi West.

Epiphyllous; spots circular, gray to gray-brown; pycnidia mi-
nute, numerous, brown, scattered, erumpent; conidia cylindric,
straight or curved, 5-guttulate; cirri white. On cultivated Sedum.

S. hedere West. is on Hedera;

S. rostrupii Sacc. & Syd. and S. varians Jaff. on chrysanthe-
mum; as is also:

S. chrysanthemella Cav.”* *° Spots ochraceous, dark mar-
gined; pycnidia epiphyllous, punctiform; conidia 40-50 x 2.5-2 n,
obscurely septate. ,

It causes damping off of chrysanthemum cuttings and spotting
of the leaves.1!

S. dianthi Desm.”!

Spots yellowish, oblong, roundish or irregular; pycnidia globose,

THE FUNGI WHICH CAUSE PLANT DISEASE 523

depressed, brownish-black; cirri white; conidia elongate, cylindric,
curved, obtuse, 30-45 x 4 yu.

It is the cause of a common and injurious leaf spot of the car-
nation. The pycnidia are visible as dark specks on the blanched
background of the spot.

S. azalez Vogl.

Spots reddish-yellow; pycnidia amphigenous, immersed, globose
to depressed, black; conidia oblong cylindric, filiform, straight or
curved, 1 to 3 or more septate, constricted slightly at the septa,
12-18 x 1.5-2.5 uw; conidiophores cylindric, short, 3-5 yu long.

On Azalea.

S. divaricate E. & E.

Spots whitish, amphigenous, confluent, purple-bordered; pyc-
nidia numerous, epiphyllous, lenticular, 100-120 y», dull black;
conidia 18-30 x 0.75-1 mu, nearly straight, non-septate, finely
guttulate.

It frequently injures cultivated phlox.'

S. narcissi Cass. is on Narcissus.

S. exotica Speg. is on Veronicas in cultivation.

S. fairmanii E. & E.

Spots amphigenous, scattered, subangular, 3-4 mm. dark
brown, limited by the veins, with a narrow dark margin; pycnidia
epiphyllous, scattered, rather numerous, black, subprominent,
100-112 4; conidia filiform, slightly curved, guttulate, 30-45 x
1.5-2 yw.

It parasitizes hollyhock leaves.”

S. parasitica Fau.

Spots amphigenous, white; pycnidia punctiform, innate; conidia
cylindric, 30-40 x 3.54 u.

The conidia are broader than in the preceding species and the
gross appearance is quite different. It is found associated with
rust sori on hollyhock.”

S. helianthi E. & K.

Spots brown, definite, 2.5-7.5 mm. with a yellowish elevated
margin; pycnidia epiphyllous, immersed, brown, collapsing, 105 u;
conidia linear-filiform, 3 to 5-septate, 30-70 x 2-3 y.1%

On sunflower leaves.

S. majalis Aderh. causes a leaf spot of lily-of-the-valley;

524 THE FUNGI WHICH CAUSE PLANT DISEASE

S. oleandrina Sacc. In leaf spots of oleander.

S. veronice Desm.

Spots amphigenous, small, subrotund, brownish or grayish,
becoming white, border umbrinous; pycnidia epiphyllous, glo-
bose, prominent, pale brownish-black; conidia elongate, slender,
straight or flexuose.

It is parasitic on cultivated Veronicas.!4

S. caragane Hen. is on Caragana.

S. ochroleuca B. & C.

Spots scattered, suborbicular, pale, brown margined; pycnidia
central, minute, scattered, hypophyllous, pale, collapsing; conidia
fusoid-filiform, curved, continuous or 1-septate, 25 » long.

In leaf spots on chestnut.

S. castanicola Desm. and S. castanea Lev. are on chestnut;
S. nigro-maculans Thiim. on walnuts and horse-chestnut;

S. esculi Lib. and S. hippocastani B. & Br. on horse-
chestnut.

S. pseudoplatini R. & D. occurs on sycamore and maple;

S. fraxani Desm. on ash;

S. cercidis Fr. on Cercis;

S. tiliz West. on Tilia;

S. curvata (R. & B.) Sacc. on Robinia leaves.

S. spadicea P. & C.4% causes a common twig blight of
pine.

Pyenidia not spot-forming, late, becoming slightly erumpent
on inner surface of browning needles, scattered, membranous,
fuscous-olivaceous, subimmersed, 190-225 » in diameter. Spores
hyaline, cylindrical, slightly curved or flexuous, apex acute,
l-septate, rarely constricted at septum, 3-4 x 30-45 p. Conidio-
phores short.

S. ulmariz Oud. Pycnidia minute, immersed, spores cylindric,
curved, hyaline, continuous, 5.0 x 2.5 u. On Spirea.

S. cornicola Desm.

Spot orbicular, margin dark purple; pycnidia‘epiphyllous, few,
black; spores cylindric, curved, 35-40 x 2-2.5 y, obsolete 2 to 4-
septate, hyaline. On Cornus.

S. parasitica Hart. is found on young spruce buds killing the
lateral shoots.

THE FUNGI WHICH CAUSE PLANT DISEASE 525

Pheoseptoria Miyabe (p. 517)

As in Septoria but with colored conidia.
P. oryzz Miy. is on rice in Japan.

Rhabdospora Montaigne (p. 518)

Pyenidia innate, erumpent, globose or depressed, brown or
black; conidia as in Septoria.

Similar to Septoria, but on stems.

R. coffeicola Del. and R. coffez Del. are on coffee;

R. theobrome A. & S. on cacao;

R. oxycocci Sh. on cranberry.

R. rubi E. Pycnidia black, subglobose, innate, erumpent,
scattered, 100-195 yw; conidia linear, curved, 3 to 4-septate, 40-
45 x 3 uw. On blackberry.

Phleospora Wallroth (p. 518)

Pycnidia innate, imperfectly developed, and chiefly formed of
modified host tissue; conidia elongate-fusoid, thick, 2 to many-
septate. About twenty-five species of leaf parasites.

This genus closely approaches the Melanconiales in structure.
Several forms have been shown to be allied to Mycospherella, e. g.,
P. ulmi to M. ulmi.

P. mori (Lev.) Sacc. on Morus =Cylindrosporium mori =My-
cosphella.

P. moricola (Pass). Sacc. on Morus is a conidial form of
Septogleeum mori.

P. aceris Lib. is found on maple and sycamore leaves;

P. oxycanthe Desm. on hawthorn leaves;

P. caragane Jacz. on Caragana.'*4

Dilophospora Desmazieres (p. 518)

Pycnidia globose, ostiolate, usually stromatic; conidia cylindric,
unicellular, with hair-like appendages at each end.

In part = Dilophia.

D. graminis Desm. =Dilophia graminis. See p. 257.

526 ‘THE FUNGI WHICH CAUSE PLANT DISEASE

Cytosporina Saccardo (p. 518)

Stroma valsoid, cushion-formed or tubercular; pycnidia sunken,
the ostiole erumpent; conidia filiform, curved, 1-celled.

Twenty species of bark and wood inhabiting fungi.

These are, in part at least, conidial forms of the Valsacee.

C. ribis Miy.’** occurs on currant and gooseberry bushes in
Holland attacking the cortex, later the wood, and killing the
shoots.

Nectrioidacez (p. 479)

Pycnidia fleshy or waxy, light colored, globose, rarely cup-
shaped or hysterioid; stroma present or absent; conidia various,
usually hyaline.

This group contains some twenty-five genera none of which are
serious plant pathogens. Some are conidial forms of the ascigerous
fungi Aschersonia and Polystigma.

Key To SUBFAMILIES AND Groups oF Nectrioidacese

Pycnidia globose, ostiolate............. I. Zythiee.
Conidia 1-celled
Byallimes s6is.505 cae sk andes we 1. Hyalospore, p. 526.
Dark colored sicsis ess dee se vxoesox 2. Phexospore.
Conidia two-celled hyaline........... 3. Hyalodidymie.
Conidia 3 to several-celled, hyaline
Elliptic to fusoid.. ............... 4. Hyalophragmie.
Bacillar to filiform................ 5. Scolecospore.
Pycnidia cupulate or hysterioid...... ,-- ID. Ollulee.
Zythiex-Hyalospore

Conidia hyaline, continuous, ovoid to elliptic.

Key to Genera oF Zythiacese-Hyalospore

Pycnidia separate
Pycnidia smooth
Pycnidia beakless
Conidia in chains................. 1. Sirozythia.

THE FUNGI WHICH CAUSE PLANT DISEASE

Conidia not in chains
Pycnidia on creeping hyphe. .. ..
Pycnidia without mycelium
Conidia spiny or ciliate
Conidia spiny. .............
Conidia with several cilia at
EPOX gs Gwe ded cncaes
Conidia smooth
Pycnidia single-walled
Pycnidia more or less papil-

Pycnidia with crateriform
ostiole. ..............
Pycnidia cup-shaped. .....
Pycnidia with outer circum-
scissile wall. ...........
Pycnidia beaked.
Pyenidia hairy or spiny
Pycnidia densely beset with conoid
I-celled sete. ..............0...
Pyenidia with slender bristles or hairs
Hairs fasciculate. .................
Hairs separate
Hairs everywhere but at the apex
Hairs only around the wide ostiole
Pycnidia cespitose or in a stroma
Pycnidia cespitose, beaked; conidia in
CHSINS | ee sdegs ouleraws Hanae
Pycnidia in a stroma
Stroma more or less pulvinate
Conidia fusoid....................
Conidia globose... ................
Stroma fruticose, branched; conidia
Dbacillars sicsiecae setae saiv ue eee a

Zythia Fries

2.

10.

11.

12.

13.

14.

15.
16.

17

527

Eurotiopsis.

- Roumegueriella.

. Ciliospora.

. Zythia, p. 527.

. Libertiella.
. Lemailis.

. Dichlena.

. Spheronemella.
Muricularia.
Collacystis.
Chetozythia.
Pseudozythia.
Treleasiella.
Aschersonia.
Munkia.

. Hypocreodendron.

Pycnidia erumpent or superficial, globose, with more or less
evident papillate ostioles, white or bright colored; conidia ovate

or elongate.
Some twenty species.

528 THE FUNGI WHICH CAUSE PLANT DISEASE
Z. fragarie Laib. Is said to cause a strawberry disease.

Leptostromatacee (p. 479)

Pyenidia membranous or carbonous, black, more or less dis-
tinctly dimidiate, scutiform, astomous, ostiolate or cleft, erumpent
or superficial. Over two hundred species.

Key to Sections or Leptostromatacee.

Conidia 1-celled

Hyg hne.s ois 2 52. ceusst gatos cade sate 1. Hyalospora, p. 528.

Coloreds <i sane deena ean isthe see es 2. Phzospore, p. 531.
Conidia 2-celled

Hyaline. ............ siuvacial sea Shue 3. Hyalodydime.

Golored s & so: caehxeia ie Seale aad ee 4, Pheodidyme.
Conidia 3 to several-celled

Hyaling:. coscccakes hota eee 5. Hyalophragmia, p. 531.

Colored........... d Oe tad a tereatetectnd 6. Pheopharagmiz.
Conidia 1 to several-celled, filiform .. ... 7. Scolecospore, p. 532.

‘

Leptostromatacez-Hyalospore
Conidia hyaline, 1-celled, globose to ovoid.

Key To GENERA or Leptostromatacee-Hyalosporse

Pycnidia separate
Pycnidia astomous or variously perforate,
but not cleft

Conidiophores lacking
Pycnidia on a subicle
Subicle of fumaginous hyphe..... 1. Eriothyrium.
Subicle of broad fibers. .......... 2. Trichopeltulum.

Pycnidia without subicle
Conidia muticate
Pycnidia stellately divided or

Chefs. se sect ge tees aw cans 3. Actinothecium.
Pycnidia depressed-clypeate, not
stellate...............00. 4, Leptothyrium, p. 529.
Conidia setulose at each end..... 5. Tracyella.

Conidiophores present, cylindric... ... 6. Piggotia, p. 530.

THE FUNGI WHICH CAUSE PLANT DISEASE 529

Pycnidia more or less clearly cleft length-

wise
Pycnidia elongate or lanceolate. ...... 7. Leptostroma, p. 530.
Pyenidia subcircular................ 8. Labrella, p. 530.
Pycnidia in a stroma
Stroma phyllogenous. ................. 9. Melasmia, p. 530.
Stroma growing on animal hairs. ....... 10. Trichophila.

Leptothyrium Kunze & Schweinitz (p. 528)

Pycnidia superficial or erumpent, dimidiate, scutiform, mem-
brano-carbonous, black, coalescing or scattered, ostiole variable,
structure cellular; conidia ovoid-oblong to fusoid.

Some one hiindted species.
In part=Gnomonia and Gnomoniella.
L. alneum (Lév.) Sacc. on alder=Gnomoniella bes

tubiformis. See p. 274. Fic. 362.—Lepto-
‘L. pomi (M. & F.) Sacc.13% 187 thyrium oxy-
, 3 3 oa cocci. Four

Forming minute superficial black spots; pycnidia spores. After
differentiated in late winter, 25-100 yu; conidia el- ry
liptic, 12-14 x 2-3 uw. The mycelium of the spots breaks away
and probably functions as a reproductive body.

The fungus is common in sterile form on pomaceous fruits but
the sporing stages are rarely found.

L. periclymeni Desm., L. acerinum Ktz. and L. buxi Pass. are
on Lonicera, acer and box respectively.

L. oxycocci Sh. 1”

Pyecnidia black, dimidiate, amphigenous, scattered, subco-
riaceous to coriaceous, irregularly subglobose,
subepidermal, erumpent, rupturing irregularly;

nil conidia subfusoid, sometimes slightly curved,
oe ee pseudoseptate, 10-15 x 2.5-3 u; conidiophores
Fic. 363 pie simple, straight, tapering, slightly longer than

thyrium oxycocci. the conidia.

Section of a pyc-

epee a Sree On cranberry.

acter. After L. macrothecium Fel. is said to cause a
Ghee strawberry disease.

L. peone Br. & Cav. is on peony leaves.

L. parasiticum Poll. is on Cereus stems in Italy.

530 THE FUNGI WHICH CAUSE PLANT DISEASE

An undetermined species has been reported as a “fly speck” on
cabbage. 8

Piggotia Berkley & Brown (p. 528)

Pycnidia applanate, inequilateral, thin-membranous, later with
a stellate cap which is thrown off forcibly; conidia elongate or
cylindric.

A genus of less than ten species.

P. astroidea Berk. & Br. parasitizes elm leaves.

P. fraxini B. & C.

Perithecia hypophyllous; spores oblong, 5-7 » long. On ash,
causing leaf spot.

Leptostroma Fries (p. 529)

Pycnidia dimidiate, subsuperficial, applanate, elongate, black,
more or less hysterioid; conidia ovate, elongate or allantoid.

In part=Hysteriacee. There are some sixty species.

L. larcinum Fel. on larch=Mycospherrella larcina. See p. 249.

L. piricola B. & S. occurs on the pear;

L. punctiforme Wallr. on willow.

Labrella Fries (p. 529)

Pyenidia black, round, often indefinite; spores long, fusiform,
or spherical, hyaline, continuous.

L. piricola Bres. & Sacc. is on pear leaves;

L. coryli (Desm. & Rob.) Sacc. on Corylus.

Melasmia Léviellé (p. 429)

Pycnidia dimidiate, carbonous, black, often on an effused black
stroma; conidia allantoid.

In part=Rhytisma. Over twenty species.

M. acerina Lév. is the conidial form of Rhytisma acerinum.
See p. 158. M. punctata S. & R. and M. salicina Lév. of the two
corresponding Rhytismas. See p. 158.

THE FUNGI WHICH CAUSE PLANT DISEASE 531

Leptostromatacez-Phzospore (p. 528)
Conidia globose to oblong, 1-celled, dark.

Key to GENERA OF Leptostromataces-Phospore

Pyenidia separate
Pyenidia on a dark subicle, radiately de-
SCENE 5 ease ew oie ed ae oaks 1. Asterostomella.
Pycnidia not on a subicle
Conidia conglobate, verrucose........ 2. Discomycopsella.
Conidia not conglobate, smooth...... 3. Pirostoma, p. 531.

Pycnidia in a stroma
Stroma membranous

Pyenidia distinct, exserted........... 4. Peltostroma.
Pycnidia merely locules, immersed.... 5. Lasmenia.
Stroma carbonous; locules many,
immersed. ...............0.00000- 6. Poropeltis.

Pirostoma Fries

Pycnidia separate, shield-shaped, rounded or elongate, leathery,
conidia globose to ellipsoid.

A genus of less than five species.

P. farnetianum Poll. occurs on Pandanus in Italy.

Leptostromatacee-Hyalophragmie (p. 528)
Conidia oblong to fusoid, hyaline, 2 to several-septate.

Key to Gengra or Leptostromatacee-Hyalophragmie

Pyenidia astomous or ostiolate, not cleft
Conidia muticate; pycnidia with creeping
hy phe isd 5 este datos todos 1. Asterothyrium.
Conidia ciliate
Conidia fusoid, 1-ciliate at each end.. 2. Discosia, p. 531.
Conidia cruciate, each arm 1-ciliate.. 3. Entomosporium, p. 532.
Pyenidia rimose dehiscent... ............ 4, Cystothyrium.

Discosia pini Heald has been reported as a parasite on pine
hypocotyls.

532 THE FUNGI WHICH CAUSE PLANT DISEASE

Entomosporium Léviellé (p. 531)

Pycnidia depressed, subglobose, not ostiolate, black; conidia
4-celled, cruciate, each arm 1-ciliate.

A genus of three species of parasites. In part=Fabrea.

E. mespili (D. C.) Sace. =F. mespili. See p. 150.

E. maculatum Rev. on pear and quince=F. maculata. See
p. 149.

E. thumenii (Cke.) Sacc. occurs on hawthorn.

Leptostromatacez-Scolecospore (p. 528)

Conidia usually hyaline, linear or filiform, continuous or septate.

Key to Genera or Leptostromatacex-Scolecospore

Pycnidia astomous or opening variously
Pycnidia with a round ostiole; conidia

catenulates s+.s ccs ebawtenas saeaies 1. Crandallia.
Pycnidia astomous or irregularly dehis-
cent
Pyenidia with radiate-fimbriate mar-
Pil rong veate pie ade oe oe hebe te 2. Actinothyrium.

Pycnidia not radiate-fimbriate
Pycnidia of two kinds, small simple,
and large and loculate. ........ 3. Brunchorstia, p. 532.
Pycnidia of one kind
Conidia muticate
Pycnidia corrugate, not hairy;

conidia not separating..... 4. Melophia.
Pycnidia hairy; conidia separat-
ing into joints............ 5. Chetopeltis.
Conidia ciliate-penicillate at
APRs ahouvoaancne ons Redes 6. Giulia.
Pycnidia elongate, longitudinally cleft. .... 7. Leptostromella, p. 533.

Brunchorstia Eriksson

Pycnidia erumpent, irregular in form, the smaller occurring
singly, the larger as chambers in a stroma, opening by an irregular
pore; conidia filiform, septate. A single species.

B. destruens Erik. on pine=Cenangium abietis. See p. 151.

THE FUNGI WHICH CAUSE PLANT DISEASE 533

Leptostromella Saccardo (p. 532)

Pycnidia at first covered, at maturity apparently superficial,
depressed convex, subcarbonous, dark colored; conidia bacillar
or filiform, continuous or sep- sas
tate. See

About twenty species, chiefly oe e
of no economic importance.

L. elastice E. & E.

Spots large, more or less el- en .
liptic, whitish, sordid, purplish ~ es
margined ; pycnidia epiphyllous, Fic. 364.—Leptostromella elastice.
hysterioid, 0.5-0.7 mm.; longi- After Stone and Smith.
tudinally dehiscent; conidia oblong, hyaline, continuous, 12-15 x
4-5 wu; conidiophores 12-15 x 3-4 y; obtuse, subolivaceous.

The cause of leaf spots of Ficus elastica.1

Excipulacee (p. 479)

Pycnidia membranous to carbonous, black, cup-shaped, patel-
late or hysterioid, at first more or less spherical but at length widely
open, erumpent or superficial, glabrous or hairy.

Key To Sections or Excipulacez

Conidia globose to fusoid, continuous

Hyalin@s is set esaakia geet cea a I. Hyalospore, p. 533.
COlOTEO ose ezsceceace ss oe BE ee den .... IL. Pheospore.
Conidia 1-septate, hyaline. .............. III. Hyalodidyma, p. 536.
Conidia 2 to several-septate e
Hyalinevsec-stssetcei ese eateries IV. Hyalophragmiz.
Coloréds so. acdc e sane gain eae ees V. Pheophragmie.
Conidia filiform or bacillar............... VI. Scolecospore, p. 536.

Excipulaceze-Hyalospore

Conidia hyaline, continuous, globose to oblong.

534

THE FUNGI WHICH CAUSE PLANT DISEASE

Key ro Genera oF Excipulacez-Hyalospore

Pycnidia pilose or setose
Conidia muticate; pycnidia cupulate. ...
Conidia ciliate; pycnidia cupulate
Conidia several-ciliate at apex. .......
Conidia 1-ciliate at each end. ........
Pycnidia smooth or nearly so
Pycnidia more or less cup-shaped, or dis-
ciform
Pycnidia black
Pycnidia composed of conglutinate

1.

Pycnidia with cellular context
Pycnidia cup-like when mature,
sometimes obconoid
Conidiophores simple
Pyenidia cup-shaped. .......
Pyenidia terete-conic. .......
Conidiophores branched. ..... .
Pyenidia subglobose, disciform or
verruciform
Pycnidia subglobose, irregularly
dehiscent and collabent....
Pyenidia disciform, often im-
perfect and covered by
epidermis..............
Pyenidia verruciform; conidia
mucose-involute. ......... 10.
Pyenidia purple................-..-- 11.
Pyenidia hysterioid or valvately gaping
Pycnidia widely hysterioid
Pycnidia valvately gaping
.Conidiophores typically branched. .. 13.
Conidiophores simple or none... .... 14.

Amerosporium, p. 534.

. Polynema.
. Dinemasporium, p. 535.

. Godroniella.

. Excipula.
. Catinula.
. Heteropatelia.

. Dothichiza, p. 535.

. Discula, p. 535.

Agyriellopsis.
Lemalis.

. Psilospora.

Sporonema, p. 535.
Pleococcum.

Amerosporium Spegazzini

Pycnidia subcupulate, setulose, conidia cylindric to ellipsoid.
Some twenty-five species, chiefly saprophytes.

A. eeconomicum E. & T.

THE FUNGI WHICH CAUSE PLANT DISEASE 535

Spots orbicular, 2-6 mm., white above with a reddish border,
mostly entirely reddish below; pycnidia epiphyllous, erumpent,
conic-hemispheric, broadly perforate above, beset with straight,
spreading, grayish-black, septate bristles, 100-150 x 4 yu; conidia
oblong-fusoid, 18-27 x 4 pu.

Very common on cowpea leaves in circular spots, with dark
pycnidia in concentric circles on white background.‘

Dinemasporium Léviellé (p. 534)

Pycnidia cupuliform, superficial, black, with dark bristles;
conidia elongate or allantoid, with apical spines.

Some thirty species, chiefly saprophytes.

D. oryze Miy. is on rice.

Dothichiza Libert (p. 534)

Pycnidia erumpent, roundish, somewhat disculate, irregularly
dehiscent; conidia elongate or cylindric. In part =Cenangium.

About eleven species, chiefly saprophytes.

D. populea S. & B. parasitizes poplar.”

Discula Saccardo (p. 534)

Pycnidia disciform-patellate, imperfectly differentiated from
the substratum; conidia ellipsoid, elongate or cylindric.

Some twenty-five or thirty species, chiefly saprophytes.

D. platani (Pk.) Sacc.=Gnomonia veneta. See p. 274.

Sporonema Desmazieres (p. 534)

Pyecnidia subepidermal, erumpent, at first
closed, then opening radiately; conidia ovate
or cylindric.

Some sixteen species, chiefly saprophytes.

S. platani Baum on Platanus=Gnomonia Fie. 365.—Sporonema
veneta. See p. 274. cepreardl omcnnpeny

S. phacidioides Desm.=Pseudopeziza tri-
folii. See p. 148.

S. oxycocci Sh.!”

Pycnidia amphigenous, excipuliform, thickened at the base,

ee 4
75

f

536 THE FUNGI WHICH CAUSE PLANT DISEASE

gradually disappearing above, immersed, erumpent, depressed-
globose, gregarious or scattered, 50-100 uy, sometimes collapsing
rupturing irregularly by a slit or triangular split; conidia cylindric,
straight, 17-19 x 3-4 uy; conidiophores simple, oblong to subglobose,
about 14 the length of the spore, or less. On cranberry.

S. pulvinatum Sh. is also on cranberry.

Excipulaceze-Hyalodidymz (p. 533)
Conidia hyaline, 1-septate, oblong or fusoid.

Key Tro Genera oF Excipulacez-Hyalodidyme

Pycnidia discoid or patellate
Pycnidia discoid, veiled; conidiophores

SIMPIEs goa sev ved exawa tsar ees 1. Discella, p. 536.
Pycnidia patellate, subsuperficial; conid-

jophores branched. ..............- 2. Pseudopatella.

Pycnidia hysterioid or irregularly gaping

Pycnidia hysterioid, elongate........... 3. Scaphidium.
Pycnidia globose, then irregularly gaping;

conidia catenulate................ 4. Siropatella.

Discella Berkley & Broome

Pycnidia disco-patellate, imperfectly formed; conidia fusoid
or oblong. Some twelve or fifteen species, chiefly saprophytes.

D. cacaoicola A. & S. is on cacao in Africa.

The Excipulaceze-hyalophragmiz, Excipulacee-pheophragmize
contain no important parasites.

Excipulacez-Scolecospore (p. 533)

Conidia typically hyaline, bacillar or filiform, continuous or
septate.

Key To Genera or Excipulacee-Scolecospore
Pycnidia separate
Conidia separating at the joints........ 1. Schizothyrella.
Conidia not separating
Pycnidia discoid, covered, erumpent,
margin lacerate; conidia filiform.. 2. Protostegia.

THE FUNGI WHICH CAUSE PLANT DISEASE 537

Pycnidia mostly cupulate, not lacerate;

conidia hamate. ................ .8. Oncospora.
Pycnidia in a stroma
Pycnidia pezizoid.................0. 4, Ephelis, p. 537.
Pyenidia superficial. ................ 5. Pseudocenangium.

Ephelis Fries

Stroma black, subeffused, sclerotioid; pycnidia pezizoid, sunken
in the stroma; conidia, cylindric to filiform.

Some seven species, chiefly of no economic importance.

It is a conidial form of Balansia. See p. 209.

Melanconiales (p. 479)

Mycelium internal; true pycnidia never developed, the conidio-
phores form a stratum; strata typically bearing conidia in acervuli
which are immersed or erumpent, black or light colored, waxy,
corneous or even submembranous, accompanied by sete or not;
conidia variable.

The common name “anthracnose” is applied to any disease
caused by a member of this order.

A single family Melanconiacez which contains about forty-five
genera and over twelve hundred species.

Key To Sections or Melanconiaces

Conidia globose to elongate
Conidia continuous

Hyalines 2 22.0.0 ccc ne dcaw ees I. Hyalospore, p. 538.
Colored: oc. Seewecenceisavonks II. Pheospore, p. 553.
Conidia 1-septate
Pyalin@.ci: oo icins Sint aed aes 5 IfI. Hyalodidyme, p. 555.
Colored. «... 2. -20.c0--48er sees IV. Pheodidyme, p. 556.
Conidia 2 to many septate
Hyaline. . ...............20005. V. Hyalophragmiz, p. 556.
Colored: =. 25:3 sass eda alive eek VI. Pheophragmia, p. 557.
Conidia muriform, dark. .......... + VII. Pheodictye.
Conidia long-cylindric to filiform. .... VIII. Scolecospore, p. 561.

Conidia stellate............2......-- IX. Staurospore.

538 THE FUNGI WHICH CAUSE PLANT DISEASE

Melanconiacez-Hyalospore (p. 537)
Conidia hyaline, 1-celled, globose to oblong, rarely dilute colored.

Key ro Genera or Melanconiacee-Hyalospore

Conidia muticate
Masses, or acervuli, not setose
Conidia not catenulate
Conidia not allantoid

loidys.0 Sere eee nee 1, Hainesia.
Masses gray to black, rarely
bright colored, waxy or horny

Growing, for the most part, on :
leaves or fruits............. 2. Gleosporium, p. 539.
Growing usually on twigs of trees
or shrubs. ............... 3. Myxosporium, p. 546.
Masses black, discoid, horny..... 4. Melanostroma.
Conidia allantoid. ................ 5. Neemospora, p. 547.
Conidia in chains
Masses oblong, hysterioid, dark,
aT 6s bccn see shh a ceo 6. Hypodermium, p. 547.
Masses discoid, pulvinate or conoid
Masses bright colored, soft....... 7. Myzxosporella.
Masses dark to black
Conidiophores repeatedly
branched
Masses discoid; conidiophores
dichotomous. .......... 8. Blennoria.

Masses depressed-pulvinate;
conidiophores verticillate 9. Agyriella.
Conidiophores simple 7
Masses scutellate, olive or

BSH. oie sage nye. cetioms 10. Myxormia.
Masses truncate, black below,

pale above. ............ 11. Bloxamia.
Masses setose at margin; conidiophores

short, fasciculate.. ............... 12. Colletotrichum, p. 547.
Conidia aristate with a branched awn at

BPOK coe sae gies soto ee wages a ly iets 13. Pestalozziella.

\

THE FUNGI WHICH CAUSE PLANT DISEASE 539

Gleeosporium and Colletotrichum are prominent in pathology as
the “anthracnose fungi”’ and cause many important diseases. The
two genera, separated only by the occurrence or non-occurrence of
sets, contain many species which have been transferred from one
of these genera to the other on this character, which is to some ex-
tent a variable one depending upon the supporting medium, con-
ditions of growth and the particular strain of the fungus under
observation.

Many form-species have been described solely on a basis of
the hosts affected. Subsequent culture study, and cross inocula-
tion has often failed to sustain these species so that many forms
that were formerly considered as distinct are now grouped under
one name. No satisfactory disposition of these forms can be made
until their ascigerous stages are known and compared and their
biologic relations investigated.

Such work as has been done (see page 267) leads rather to con-
solidation than to segregation of species.

For sake of clearness and convenience, mention is made below
of many form species of these two genera under their old names,
though the evidence now is that in many instances they should be
consolidated with other species.

Gleosporium Desmazieres & Montaigne (p. 538)

Conidial layer subepidermal, disciform or pulvinate, usually
erumpent, pale or fuscous; conidia ovate, rarely oblong; conidio-
phores needle-shaped.

In part=Glomerella, Pseudopeziza, Gnomoniella, Gnomonia,
Trochila, Physalospora, Calospora.

There are over three hundred species of parasites, many of
them very important pathogens. The spores in germination
commonly form dark colored, thick-walled chlamydospores and
usually become 1-septate.

G. rufomaculans (Berk.) Thiim. on a large variety of hosts=
Glomerella rufomaculans. See p. 264.

G. melengonea E. & H. is reported on egg-plant fruits in New
Jersey;!® G. orbiculare Berk. on cucurbs;

G. fructigenum Berk. on many fruits.

G. leticolor Berk. on peaches and apples and G. versicolor

THE FUNGI WHICH CAUSE PLANT DISEASE

540

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THE FUNGI WHICH CAUSE PLANT DISEASE 541

B. & C. on peaches are probably all identical with Glomerella
rufomaculans.

G. salicis West. on Salix=Pseudopeziza salicis. See p. 148.

G. piperatum E. & E. on pepper=Glomerella piperata. See
p. 269.

G. cylindrospermum (Bon:) Sacc. on Alnus=Gnomoniella tubi-
formis. See p. 274.

G. vanillz Cke. on orchids=Calospora vanilla. See p. 280.

G. macropus Sacc. on Cattleya=Physalospora cattleya. See
p. 253.

G. cinctum B. & C. on orchids=Glomerella cincta. See p. 269.

G. paradoxum (de Not.) Fel. on Hedera=Trochila craterium.
See p. 157.

G. cingulatum Atk. on privet=Glomerella cingulata. See
p. 268.

G. psidii Del. on guava=Glomerella psidii. See p. 270.

G. atrocarpi Del. on Atrocarpus=Glomerella atrocarpi. See
p. 278.

G. nervisequum (Fcl.) Sacc. on sycamore=Gnomonia veneta.
See p. 274.

G. ribis (Lib.) M. & D. on Ribes=Pseudopeziza ribis. See
p. 148.

G. bicolor M. Cal. occurs on grapes in Australia,

G. ampelophagum (Pass.) Sacc.!41"148

Spots subcircular often confluent, from cortex of the berry, cen-
ters gray; margin dark or red. Acervuli subepidermal, minute, col-
lected; conidia oblong, ellipsoid or ovoid, 5-6 x 2-3 y, hyaline.

Small dark spots are produced on fruit, leaf or cane of grape.
These later enlarge and show white centers with dark or even red
borders. The mycelium lies just below the epidermis. On shoots
the cambium is killed and cankers develop. Two kinds of spores
have been found by Viala and Pacottet!*3 one very small and linear,
the other larger and in Phoma-like pycnidia. Common in the
eastern United States and Europe.

G. depressum Penz. is on Citrus.

G. spegazzinii Sacc; and G. intermedium Sacc. grow on Citrus
fruits; G. citri Mas., G. hendersonii B. & Br. on oranges causing
leaf scorch in England, and Trinidad.

542 THE FUNGI WHICH CAUSE PLANT DISEASE

G. variabile Lau. grows on Ribes alpinum. G. curvatum
Oud. is described as a currant parasite.

G. malicorticis Cor. i

Caulicolous; spots brownish, slightly depressed, irregular in
outline; acervuli minute, erumpent; conidia elliptic, curved,
hyaline or greenish-tinged,
granular, 24 x 6 yu.

On apples in northwestern
United States. Neofabrea has
been reported as genetically
connected.

G. cydonie Mont. is re-
corded as a parasite on the
quince.

G. musarum C. & M. is a
common wound parasite on
bananas.

Acervuli innate; erumpent,
gregarious, rose-tinged; conidia
elongate-ellipsoid, ends
rounded, 10-12 x 4-5 yu, gran-
ular. A variety, importatum,
is also recognized.

Fic. 367.—G. malicorticis; a, acervulus; G. diospyri E. & E.

E, germinating spore. After Cordley. — Acervuli on yellowish dis-
colored areas, innate, erumpent, epiphyllous, on the leaf veins, mi-
nute, tuberculiform, pale; conidia ovate, granular, 6-14 x 5-7 yp.

On persimmon.

G. fragarize (Lib.) Mont.

Spots indeterminate, red, epiphyllous; acervuli applanate,
rugulose, black; conidia cylindric, 4 to 5-guttulate.

On strawberries but not usually troublesome.

G. amygdalinum Brizi.° occurs on the green fruit of the al-
mond in Italy.

G. venetum Speg.34 146-148

Caulicolous or foliicolous; spots orbicular or elliptic, border
raised, darker, 2-3 mm. in diameter; conidia oblong, elliptic,
5-7 x 3 yw, in mass amber-colored.

THE FUNGI WHICH CAUSE PLANT DISEASE 543

The fungus occurs on all aérial parts of the raspberry and is
wide-spread in Europe and America causing serious disease. On
canes small purple spots first show near the ground, enlarge and
soon develop ashen centers. The leaf spots are small, often
scarcely 1 mm. in diameter.

G. mangiferee Hen. is found on mango leaves in Cuba '® °°
and other West Indian Islands.

- olivarum d’Alm. parasitizes olive fruit in Europe.
- minus Sh. is on cranberry.!”

- myrtilli All. is injurious to Vaccinium myrtillus.

. coffeanum Del. occurs on coffee in Java;

. pestis Mass. on yam leaves in Fiji.

. trifolii Pk.1517152

Spots subcuticular, brown, suborbicular, concentrically zonate;
conidia oblong to cylindric, obtuse, 15-23 x 4-6.3 p.

The fungus was first observed in America and what was regarded
as the same was later seen in Europe as the cause of dying of stems
and leaves of clover.

G. caulivorum Kirch.1

Caulicolous, spots forming long dark streaks, more or less sunken,
blackish-bordered; acervuli minute; conidia curved, more or less
pointed, 12-22 x 3-5 yp.

This was said by Kirchner (see 7**) to be the cause of the more
serious European anthracnose affecting stem, fruit and leaf of
clover. Fulton !*4 in 1910 reported it in America and showed that
pure cultures of the fungus readily produced infection in wounds or
even on unwounded succulent parts when in humid air. The conidia
have been known to live twelve months.

G. morianum Sacc. is on alfalfa.

G. medicaginis E. & K.

Acervuli scattered, innate, blackish, rather large, visible on both
sides the leaf, opening below; conidia oblong, cylindric, granular,
subhyaline, more or less narrowed at the middle, 15-20 x 3-4 u.

On withered leaves and stems of alfalfa, defoliating the lower
part of the stem.

G. manihotis Hen. is found on Cassava in Africa.

G. lagenarium (Pass.) Sacc. on cucumbers is probably identical
with Colletotrichum lindemuthianum.

QQQ9000

544 THE FUNGI WHICH CAUSE PLANT DISEASE

G. concentricum Grev. causes spotting of leaves of cabbage,
cauliflower, etc.

G. cattleye (P. & D.) Sacc. grows on leaves of Cattleya;
G. dianthi Cke. on carnation in England. G. clematidis Sor. is
found on cultivated clematis stems;!*”

G. rose Hals.?! is reported by Halsted on rose canes causing
injury similar to that of G. venetum on the raspberry.

G. mezerei Cke. is on Daphne.

G. affine Sacc. grows on various orchids and Hoya. G. oncidii
Oud. on Oncidium.

G. euphorbie Hals. is on clusters and stems of spurge.”!

G. stanhopeicola Hen., G. leli# Hen. and G. pallidum Karst.
& Har. are on orchids; G. helicis (Desm.) Oud. on English ivy.

G. cactorum Ston. occurs on a number of species of cacti;

G. beyrodtii Klitz on Vanda;

G. opuntiz E. & E. on Opuntia;

G. elastice C. & M. on Ficus;

G. bruneum Petch. and G. alborubrum Petch. on Hevea.

G. rhodendendri Br. & Cav. forms yellow spots on various
species of Rhododendron.

G. aquilegie Thiim is on Aquilegia.

G. viola B. & Br.®

Spots pale, becoming whitish; acervuli very thin, solitary;
conidia yellowish. Causing leaf spots on cultivated violets.

G. cytisi B. & Br. is on Jaburnum;

G. bidgoodii Cke. is on Oncidium;

G. pelargonii C. & M. on Pelargonium.

G. crotonis Del. occurs on Codizeum.

G. soraurianum All. also on Codizeum leaves and described as
a dangerous parasite is perhaps identical with G. crotonis.

G. anthuriophilum Trinch. causes spots on Anthurium leaves.

G. begonize Magnag. is on begonias in Italy.

G. fagicolum Pass. is widespread and destructive to beech
in Germany.

G. umbrinellum B. & Br. is found on Quercus;

G. inconspicuum Cav. on elm;

G. thee-sinensis Miy. and G. thee Zimm. on tea in Japan and
Africa.

THE FUNGI WHICH CAUSE PLANT DISEASE 545

G. allescheri Bres. and G. nanoti P. & D. occur on
Palms.

G. tiliz Oud. is a serious parasite on the twigs, petioles and leaves
on the linden in Denmark.

G. tiliaceum (All.)* said to be distinct from the above occurs
in Germany on Tilia.

G. juglandis (Lib.) Mont. causes a common, and serious leaf
blight of the butternut.»

G. fagi (D. & R.) West is on Fagus;

Spots subcircular, fuscous above, olivaceous, vitreous be-
neath; acervuli small, prominent, honey-colored; conidia oklong
ovate, 15-20 x 7-8 yu, minutely 1 to 3-guttulate; conidiophores
fasciculate, cylindric, fuscous.

G. apocryptum E. & E. causes a nursery disease of maples
and of box elder.’

Acervuli numerous, minute, mostly hypophyllous, on dead areas
of the leaf; conidia very variable in size, 5-12 x 214-5 y, oblong
to narrowly elliptic.

G. betularum E. & M.

Spots rounded, 2-3 mm., blackish margined; acervuli amphig-
enous, brownish, 120-140 yu, becoming cupulate; conidia hyaline,
obovate, 9-10 x 5-6 uy.

It is common on leaves of American birches.

Other common species on deciduous trees are:

G. tremulz (Lib.) Pass. on Populus;

G. betulinum West. on beech;

G. alneum West. on alder;

G.carpini (Lib.) Desm. on Carpinus;

G. coryli (Desm) Sacc. on Corylus;

G. quercinum West. on oak;

G. nervicolum Massal on oak.

G. kawakamii Miy. is found on Paulownia in Japan causing
witches’ brooms.

G. saccharini E. & E.

Acervuli minute, numerous; spores oblong-fusoid, 6-7 x 1.5-3 yu,
hyaline, continuous. On maple.

G. caryz E. & D. =Gnomonia carye.*”

Spots suborbicular, 1-2 cm., margin subdefinite; acervuli

546 THE FUNGI WHICH CAUSE PLANT DISEASE

hypophyllous, numerous, 75-150 y; spores allantoid, continuous,
7-10 x 1.5-2 uw. On Carya.

G. berberidis Cke.

Hypophyllous; acervuli collected, numerous; spores ovoid,
5x3 yu. On Barberry.

G. tamarindi Hem. is on tamarinds, in Africa.

G. canadense E. «& E.

Spots amphigenous, center pale, border brownish; acervuli few,

Fic. 368.—M. corticolum, on apple twig. After
Edgerton.

180-200 u; spores ovate-oblong, hyaline, 10-14 x 3.5-4.5.
On white oak.

Myxosporium Link (p. 538)

Acervuli immersed or superficial, indefinite, pallid or reddish;
conidia ovate, hyaline or pale, conidiophores slender-cylindric.
Some seventy species, some of which are important pathogens.

In part=Gnomonia. See p. 274.

M. valsoideum (Sacc.) All. on sycamore=Gnomonia veneta.
See p. 274.

M. corticolum Edg.

Acervuli erumpent, originating under several layers of cortex,
1-2 mm. in diameter, scattered over the diseased area; conidia
straight or curved, cylindric, very densely granular, 18-36 x 6-9
H, oozing out of the pores in white cirri; conidiophores very
short. Very similar to an immature Spheropsis malorum but
considered distinct by Stewart and his associates.®8

It formas bark cankers in pear and apple in America.

THE FUNGI WHICH CAUSE PLANT DISEASE 547

M. longisporum Edg.**

Acervuli erumpent, subcorticular, variable in size up to 1.5 mm.,
scattered over the host in poorly defined rows; conidia straight
or curved, 30-48 x 12-15 u, oozing out in white cirri; conidio-
phores very short.

On twigs of Liriodendron.

Other parasitic species are:

M. piri Fcl. on pear; M. mali Bres. on apple; M. abietinum
Rost. on conifers; M. devastans Rost. on beech; M. lanceola S. &
R. on oak; M. carneum Lib. on beech twigs.

Neemaspora Persoon (p. 538)

Acervuli subgelatinous, indefinite, bright colored; conidia
allantoid, short, with a bristle at each end.

N. crocea (Bon.) Sacc. is reported by Massee as the cause of
die-back of peach shoots in England.!®

Hypodermium Link (p. 538)

Acervuli subcuticular, erumpent, elongate, black; conidia ovate-
oblong, catenulate.
H. orchidearum Cke. is on Cymbidium.

Colletotrichum Corda (p. 538)

Acervuli innate erumpent, discoid or elongate, dark, surrounded
with long black sets; conidia terete to fusoid; conidiophores short.

The genus is distinguished from Glceosporium by the presence
of setz, a somewhat unreliable character. See p. 539.

In part=Glomerella and Pseudopeziza. See pp. 264, 147.

Some eighty species, several of them very important plant path-
ogens.

C. gossypii Sout. on cotton=Glomerella gossypii. See p. 271.

C. cincta Ston. on orchids=Glomerella cincta. See p. 269.

C. rubicolum IE. & E. on red raspberry=Glomerella rubicolor.
See p. 270.

C. lindemuthianum (Sacc. & Magnus) Briosi & Cavara.3* 5%

164-167

548 THE FUNGI WHICH CAUSE PLANT DISEASE

Spots subelliptic to irregular, depressed, brownish; acervuli
scattered, surrounded by a few not very conspicuous black sete;
conidia oblong, ends rounded, straight or curved, 15-19 x 3.5-5.5
u; conidiophores cylindric, simple, 45-55 p.

This fungus, generally known as C. lindemuthianum, is accord-

bj

T 6
Anthracnose Spores
7,

much i.

Fic. 369.—C. lindemuthianum. Showing relation of the fungus
to the tissues of the bean. To the left above is a diagram of
a section across a bean pod through a canker. The drawing
below is a much enlarged largely diagrammatic view of a por-
tion of this same section. It shows how the mycclial threads
of the fungus may penetrate the seed coat and enter the
starchy tissue of the seed, there to remain dormant until the
following season. On the left is a spore germinating and pene-
trating the epidermis. To the right a magnified view of spores,
one germinated. After Whetzel.

ing to the cultural studies of Shear & Wood (see p. 267), probably
a variety of Glomerella rufomaculans. See p. 264.

On the bean it attacks stems, leaves, cotyledons, or the pods,
producing sunken spots of dead tissue which bear the numerous
pink acervuli. It has been shown that the mycelium on the fruit
may penetrate through the pericarp and into the seeds beneath
and there hibernate.

C. lagenarium (Pers.) E. & H.™ is probably identical with
C. lindemuthianum. It is described as the cause of spots on fruit
leaves and stems of cucumbers, watermelons, squash, pumpkins
and citron.

C. oligochetum Cav. grows on cucurbs, attacking all parts.!®
Probably=C. lindemuthianum.

THE FUNGI WHICH CAUSE PLANT DISEASE 549

C. carica 8. & H.7* 19

Acervuli brown, becoming black, hemispherical, numerous,
small, 85-250 uw, bearing 1-12 (or often 0) long, slender, irregular
sete which are dark throughout, acute, rigid, septate, 2-6 x 22-
106 yu, conidia regular, oblong, obtuse, 3.5-6.6 x 8.7-20; conidio-
phores slender, 1-2 x 45 u, hyaline.

It is the cause of a decay of figs in the United States.

C. ampelinum Cav. is on grape leaves.

C. gloeeosporioides Penz.

Acervuli sparse or scarcely gregarious, subepidermal, erumpent,
dark, cylindric, sete continuous or few-septate, dark colored,
40-90 x 5-6 yu, conidia cylindric, straight, 16-28 x 4-6 yu: co-

ee

Fic. 370.—C. carica. 5, conidiospores, spores and setz, 4, black bodies
produced on germ tubes. After Stevens & Hall.

nidiophores densely fasciculate, cylindric, rounded apically,
tenuous, 18-25 x 4-5 up.

It causes ‘‘wither tip” of orange, pomelo and lemon,!"!”? spots
on citrus leaves, lime canker, and anthracnose of stem and flower
with great financial loss in Florida, West Indies, South America,
Australia, Malta and many other localities.

In ‘“‘wither tip” the fungus enters through the terminal bud or
from leaves. On lemons attack is through bruises. Acervuli are
found on leaf, twig or fruit, breaking through the epidermis.
Cross inoculation on the various hosts and with the different forms
of the disease demonstrated the identity of all. Smith?” has
questioned the casual relation of this fungus as regards ‘‘wither-
tip” as it occurs in California.

C. falcatum Went.

Acervuli poorly defined, sete irregularly arranged, cuspidate,

550 THE FUNGI WHICH CAUSE PLANT DISEASE

100-200 x 4 u, brownish; conidia falcate, 25 x 4 »; conidiophores
ovoid, 20 x 8 u., hyaline to fuscous.

This is believed to be the chief cause of the red rot of sugar-
cane.> It was reported in*the United States by Edgerton,”
also by Stevens. Inoculation experiments indicate that it is
distinct from C. lineola, on sorghum and Johnson grass, which it
resembles morphologically.

C. cereale Manns.’”

Spots circular to ovoid, 30 mm.; acervuli dark brown, or black;
sete few or many, dark brown to black, at base 6-8 u thick,
tapering to a length of 60-120 y, continuous or 1 to 2-septate;

oe
ry

Fic. 371.—C. cereale, acervulus showing mycelium, set, conid-
iospores and spores. After Manns.

conidia 18-26 x 3-4 y, spindle to boat-shaped, 2 to several-
guttulate; conidiophores, very short, 12-6 x 1-2 u.

This fungus is parasitic on the roots, stems, blades and spikes
of rye, wheat, oats, barley, emmer, orchard grass, timothy, blue
grass and chess. The disease causes a premature ripening and
shrivelling of the grain. Superficially the diseased heads present
the same appearance as those attached by scab (Fusariose) but
no pink over-growth is present, nor is the presence of the disease
always apparent, as it was found on numerous headsof grain which
appeared to be healthy. Morphological studies indicate that all
the hosts mentioned above are affected by the same fungus. This

was confirmed by cross inoculations in the case of wheat and
emmer.

THE FUNGI WHICH CAUSE PLANT DISEASE 551

C. trifolii Bain.!”*!*

Spots dark, depressed; acervuli erumpent, scattered or gre-
garious; conidia straight, ends rounded, 3-4 x 11-13 y; conidio-
phores cylindric or fusoid, hyaline; setze few or many, continuous
or uniseptate, dark, paler apically, 4-7 x 39-62 y, sinuous, or
nodose.

It occurs as an anthracnose producer on stems, rarely on leaves,
of clover and alfalfa causing very serious injury. In general ap-
pearance it is much like Gleeosporium caulivorum.

C. spinacie E. & H.™

Spots roundish, dirty-white, or greenish, 2-4 mm.., with a slightly
raised border; acervuli amphigenous, punctiform, 40-75 yu, with
3-12 erect or spreading bristle-like sete, 60-75 x 44.5 yw, sub-
bulbous at base, subhyaline, subacute above, dark brown below;
conidia subfalcate, fusoid, 2 to 4-guttulate, 14-20 x 2.5-3 y, ends
subacute; conidiophores short.

It produces blotches on spinach leaves.

C. phomoides (Sacc.) Ches.”» > 154-157, 181

Spots depressed, circular, slightly discolored, center black,
5-10 mm., later irregular and confluent; acervuli abundant,
densely gregarious, rusty brown to black, applanate, 95-150 yu;
sete abundant, fuliginous, generally curved, septate, 65-112 yu;
conidia oblong, 16-24 x 4 yw, ends subacute; conidiophores
short, slender, 30-40 u» high, arising from a well developed
stroma. On tomato.

This is a common cause of ripe rot of tomatoes. The fungus was
studied in culture by Stoneman © who reported it as somewhat
different from G. rufomaculans, though Edgerton !* thought the
apple and tomato forms the same. Work by Gueguin 1** throws
doubt on the American form on tomato being identical with the
European form known as G. phomoides. Chester '* 44? has
reported what he regarded as the last species as setigerous.

C. nigrum, E. & H.' 7

Spots blackish, depressed; decaying; acervuli numerous, su-
perficial; setze numerous, slender, sete pointed; conidia ob-
long.

This form which appears quite different from G. piperitum was
described from New Jersey by Halsted.

552 THE FUNGI WHICH CAUSE PLANT DISEASE

C. malvarum Br. & Casp.¥ (=C. althza.)

Epiphyllous and caulicolous; spots’ brown, sunken; acervuli
erumpent; sete dark brown, abundant, 1 or 2-septate, usually
colorless below, 60-109 x 3-5 yu, appearing after the conidio-
phores which are colorless, cylindric, tapering slightly and apically
rounded, slightly longer than the conidia; conidia irregular, oblong,
granular, flesh-colored in mass, 11-28 x 5 yp.

It is described hy Southworth 1* as the cause of anthracnose of
the hollyhock. The fungus closely resembles C. lindemuthianum
but cross inoculations on the bean failed to produce disease though
on hollyhock inoculations succeeded easily.

C. schizanthi Jensen & Stewart was found on greenhouse
Schizanthus plants in Ithaca.3%

C. agaves Sacc.

Spots pale; acervuli conic; sete few, 90-100 x 5-6 yu, brownish
ochraceous, 2 to 3-septate, conidia 22-26 x 4-5 yw; conidiophore
subramose, fuscous at base. On sisil hemp and agave.!83

C. bletiz Hals. is on Bletia.

C. viole-tricoloris R. G. Sm.84185

Spots pale-yellow on leaves. Dead areas on petals occur with
more or less deformity of blossom. Spots at first orbicular and
definite, later confluent and irregular, acervuli numerous, 50-
150 u, often confluent; stroma usually poorly developed; sete
mostly single or in pairs, 20-70 yu, deep brown, 1 to 2-septate,
tapering gradually to a point; conidia oblong or slightly curved,
ends blunt, 20 x 5 yw; conidiophores short, hyaline.

It causes spotting of pansy leaves in several states and leads
to failure to bloom.

C. anthurii Del. occurs on Anthurium;

C. luxificum H. & D. on cacao in the West Indies ;

C. elastice (C. & M.) Koo. on Ficus.

Cc. primule Hals.* is reported as causing a leaf disease of the
primrose.

C. kentie Hals. is on palms.”!

C. omnivorum Hals.

Spots dry, irregular in outline; conidia 20-28 x 3-5 , falcate;
sete elongate, acute, black.

On Aspedistra and other plents.2*-

THE FUNGI WHICH CAUSE PLANT DISEASE 553

C. camelliz Mas. is on tea.

C. antirrhini Stew.

Spots depressed, elliptic or orbicular, often confluent, 3-10 mm,
acervuli numerous, crowded; stroma well developed; conidia
16-21 x 4 y, straight or curved, ends rounded; conidiophores
short; seta abundant, dark brown, 50-100 u, simple, mostly
straight and tapering uniformly to a subacute point.

It attacks the stems and leaves of the cultivated snapdragon
producing sunken spots.

. cyclamene Hals. is on Cyclamen;

. dracene Hals. on Dracena;

. coffeanum N. is on coffee;

- hevez Petch. on Hevea in India;

. cradwickii Banc. on cacao pods; a

. brachytrichum Del. on cacao leaves; ™

C. theobrome A. & S. and C. theobromicolum Del. are on
cacao.

C. incarnatum Zimm. is on Hevea and vanilla;

C. macrosporum Sacc. on vanilla;

C. pollaccii Maynag. on Japanese loquot in Italy;

C. hedericola Lau. on Hedera.

Undetermined species of Colletotrichum have been reported
on asparagus, carnation,”® pear,”* and many other hosts.

aaaaaa

Melanconiaceez-Phzospore (p. 537)

Conidia dark, continuous, globose to oblong or fusoid.

Key Tro Genera or Melanconiacee-Pheospore

Conidia solitary on the conidiophores

Conidia globose or oblong.........----- 1. Melanconium, p. 554.
Conidia fusoid, often arcuate
Conidiophores not swollen at base.... 2. Cryptomela.
Conidiophores swollen at base......./ 3. Basiascum.
Conidia in chains
Conidial chains separate... ......------ 4. Trullula, p. 554.

Conidial chains in a mucose head....... 5. Thyrsidium.

554 THE FUNGI WHICH CAUSE PLANT DISEASE

Melanconium Link (p. 553)

Acervuli subcutaneous, conic or discoid, black; conidia elongate
to globose-oblong, erumpent in black masses; conidiophore sim-
ple. In part=Trichospheria. See p. 228.

More than one hundred fifty species.

M. fuligineum 8S. & V. Cav.*4

Acervuli scattered or gregarious, at first gray-cinereous, then
brownish, subepidermal, erumpent; conidia ovoid to ellipsoid,
inequilateral, acute, 9-12 x 4-6 y, olive, guttulate; conidiophores
filiform, from a well developed stroma.

It causes the important bitter rot of ripening grapes, especially
the white varieties, occurring also on shoots
and peduncles. Acervuli appear on the
surface of the rotted berries. The myce-
lium penetrates even to the seeds.

Southworth suggested in 1891" that
this and Gleeosporium are congeneric but
Atkinson ™ who studied the fungus in pure

zB mites culture thinks them generically distinct.
Fic. 372.—M. fuligineum. Noack © who studied what he regarded as

path Amanat the typical M. fuligineum says that it is
preceded by and belongs to a Gleeosporium-form.

M. pandani Lév. is a common parasite on Pandanus in green-
houses, killing the branches.

M. sacchari Mass.!%?

Acervuli numerous, collected in indeterminate pallid orbicular
spots; conidia cylindric, 10-15 x 3-4 y, straight or slightly curved,
olivaceous, smooth.

In leaves, sheaths and culms of sugar cane. The cause of the
rind disease.

Trullula Cesati (p. 553)

Acervuli subcuticular, erumpent, discoid-pulvinate, or conical-
depressed, black; conidia oblong-cylindric, catenulate; conidio-
phores long, bacillar, simple or branched.

Some twenty species, of trifling economic importance.

T. vanille Hen. is on vanilla in Africa.

THE FUNGI WHICH CAUSE PLANT DISEASE 555

Melanconiacee-Hyalodidyme (p. 537)

Conidia hyaline, 1-septate, ovoid to fusoid.

Key to Genera or Melanconiacee-Hyalodidyme

Conidia mutic

Saprophytic, on stems and fruits........ 1. Septomyxa.
Biogenous, typically on leaves. ......... 2. Marssonia, p. 555.
Conidia 3 to 4-ciliate at each end......... 3. Gleesporiella.

Marssonia Fisch

Acervuli globose-discoid, pale, conidia ovate to elongate. In
part =Gnomonia, Trochila, Pseudopeziza.

Some seventy-five species, all leaf parasites, several of eco-
nomic importance.

M. castagnei (D. & M.) Sacc. on Populus = Trochila popularum.
See p. 157.

M. juglandis (ib.) Sacc. on walnut =Gnomonia ( G
leptostyla. See p. 275. Vs g

M. populi (Lib.) Sacc.

Spots suborbicular, epiphyllous, separate or con- é g
fluent, brown, darker margined, acervuli convex 5, 373.—M. per-
to applanate, fulvous; conidia obovate to subpyri- —_forans, conidio-
form, 20 x 12 un, constricted at the septum, pores apne
straight or curved. : Selby.

It is common on leaves of Populus as the cause of blighting
of lateral twigs. It is injurious in nurseries.”

M. panattoniana (Berl.) Mag. is found on lettuce in Italy;

M. secalis (Oud.) Mag. on rye;

M. martini S. & E. on oak;

M. potentilla (Desm.) Fisch as the cause of a disease of the
strawberry in Europe.

M. ros2 Trail causes premature fall of rose leaves.

M. perforans, E. & E.!*

Spots small; irregular, 1-2 mm., pale, soon deciduous; acervuli

556 THE FUNGI WHICH CAUSE PLANT DISEASE

‘ 100-120 yu, or by confluence larger;

pS) ~\ NY conidia abundant, clavate or wedge-
Ce shaped, 11-15 x 2.5-3 un.

The cause of leaf perforations of

lettuce.
c M. viola (Pass.) Sacc.1%
Discoloration of the host slight;
= acervuli numerous, scattered, small;

conidia curved, or straight, 15-18 x
5-6 pw, septum usually excentric.

mall spots are produced on violet
Fic. 374.—M arssonia viola. S P P
Spores and conidiophores. leaves.

atthe Somes abel Sid dan. M. medicaginis Vors. is on alfalfa.

Melanconiaceez-Phzodidyme (p. 537)
Conidia dark, 1-septate, ovoid to fusoid.

Kry To Genera or Melanconiacez-Pheodidyme

Conidia solitary

Conidia muticate. ................2.0- 1. Didymosporium, p. 556.
Conidia 1 to 3-ciliate at apex. .......... 2. Neobarclaya.
Conidia catenulate, connected by hyaline
MSE 5) aaa ones Sheena ede 3. Bullaria.

Didymosporium Nees

Acervuli rounded or elongate, covered, erumpent; conidia elon-
gate or fusoid. A genus of less than twenty species.
D. salicinum Vuill is on poplar.

Melanconiacez-Hyalophragmie (p. 537)

Conidia hyaline, 2 to several-septate, oblong to fusoid or clavate.

Key To GENERA OF Melanconiacee-Hyalophragmie
Conidia separate
Conidia muticate
Conidia oblong or fusoid, masses usually
PIES a Cogent nae saaee ss 1. Septogleum, p. 557.

THE FUNGI WHICH CAUSE PLANT DISEASE 557

Conidia long-clavate; masses dark.... 2. Rhopalidium.
Conidia 1 to several-ciliate, usually at the
BADER. sadewo hepa dige aver aatenk noas Eek 3. Pestalozzina.
Conidia united at base into a radiate or stel-
late group. . ............ 0. cece eee 4. Prosthemiella.

Septogleeum Saccardo (p. 556)

Acervuli very small, subepidermal, erum-
pent, pallid; conidia oblong. Some twenty-
five species of leaf parasites.

S. hartigianum Sacc. attacks maple, killing
very young twigs.

5. ulmi Fr. is found on elm leaves=Phylla-
chora ulmi. (?)

S. mori Lev. on mulberry=Mycospherella
mori. (?)

S. cydoniz (Mont.) Pegl. is on the
quince;

S. manihotis Zimm. on manihot in Java. ns

S. arachidis Rac. is seriously injurious to 7,4 °375.—Septo

the peanut in Java.’ gleum acerinum,
. conidiospores and
S. profusum E. & E. is found on Corylus; conidia, After Sac-

S. fraxini Hark. on ash. cardo.

Melanconiacee—Phzophragmie (p. 537)

Conidia dark, 2 to several-septate, oblong to cylindric.

Key to GENERA oF Melanconiacee-phzophragmiz.

Conidia mutic
Conidia separate, not in chains
Conidia oblong or elongate, not stellate
Conidia curved-attenuate, i. e., hya-
line-rostrate
Conidia dark, except the hyaline
béaken. se eceiveeseee ise ss 1. Scolecosporium.

Conidia with 2 inner cells opaque,

others clear. ............... 2. Toxosporium, p. 558.

558 THE FUNGI WHICH CAUSE -PLANT DISEASE

Conidia oblong, not rostrate

Conidia cirrhose protruded....... 3. Stilbospora.

Conidia not protruded........... 4, Coryneum, p. 560.
Conidia stellate-lobed, lobes several-

Seplaters waskuaicereceseswa cues 5. Asterosporium

Conidia in chains
Conidia connected with filiform isthmi 6. Seiridium.
Conidia chains without isthmi........ 7. Seiridiella.
Conidia ciliate
Conidia ciliate at apex alone

Conidia 1-ciliate. ................... 8. Monochetia, p. 558.
Conidia several-ciliate. .............. 9. Pestalozzia, p. 558.
Conidia 1-ciliate at each end. .......... 10. Hyaloceras.

Toxosporium Vuillemin (p. 557)

Acervuli sublenticular, erumpent, scattered, minute, black;
conidia curved, beaked at each end, central cells dark, apical hya-
line; conidiophores short, simple.

T. abietinum Vuill. causes drying out of Abies leaves in
Europe.

Monochetia Saccardo

As in Pestalozzia except that the conidia bear only a single
seta. About sixty species.

M. pachyspora Bubak. is common on Castanea, causing large,
circular, dead leaf spots with the acervuli showing in somewhat
concentric circles.

Pestalozzia de Notaris

Acervuli subcutaneous, erumpent, discoid or pulvinate, black;
conidia elongate, colored or the end cells hyaline, with several
hyaline setz on each end.

A genus of over two hundred species of various habit, some of
considerable economic importance.

P. hartigii Tub. causes disease of tree and shrub seedlings in

nurseries, constricting the stem just above the soil and resulting
in death.

THE FUNGI WHICH CAUSE PLANT DISEASE 559

P. funerea Desm.

Acervuli scattered, punctiform, blackish, subepidermal, erum-

pent; stroma depressed, white;
conidia oblong, fusoid, 5-celled,
constricted at the septa, the three
central cells fuscous, the others
hyaline, 22-32 x 6-8 yw, with 2-5
recurved hyaline spines, 10-15 x
0.7-1 yw; conidiophores short, 5-9 x
1-1.5 yp.

It is found on various conifers

HSK AL

3 < 2 Fic. 376.—P. funerea. A. Spores.
causing disease and is a common B.A young mycelium. G. Hypha

saprophyte. In America it causes 0f 82 0lder mycelium. After Reed.
a stem spot or anthracnose of ginseng,®‘ girdling the petioles.
The culture characters were studied by Reed.

P. guepini Desm. var. vaccinii Sh.1”
Acervuli minute, punctiform, convex,

Fic. 377.—Pestalozzia guepini vaccinii; a, a conidium
having an apical appendage with three branches;
b, a conidium having an apical appendage with
four branches; c, a germinating conidium; d, a ger-
minating conidium sending out two germ tubes.
After Shear.

P. uvicola Speg.1

black, subepidermal,
erumpent; conidia el-
liptic and somewhat
unequilateral, about
20 » long; central cells
dark, the two end cells
hyaline, the apical cell
with 3-4 filiform sete
22-35 p» long, the basal
with a short hyaline
appendage, 6-12 x.
Common on fallen
leaves of cranberries,
and associated with
rot of the berries. It

-is. common on ° tea

causing a serious dis-
ease, also on Camellia,
Magnolia, Citrus,
Rhododendron.

Acervuli globose, lenticular, black, subepidermal, erumpent,

560 THE FUNGI WHICH CAUSE PLANT DISEASE

300-400 pu; conidia fusiform, 5-celled, the three median olivaceous-
fuscous, the others hyaline, 35 x 8-10 u, inferior appendage 25-30
x 1p, superior group 8-10 x 1 u.

It is described as the cause of rot of grape berries and of a leaf
spot of the vine.

P. aloéa Trinch. occurs on aloé in Italy;

P. clusie Griff. & Mont. on Clusia leaves in France;

P, richardie Hals. sometimes disfigures calla leaves.

P. tumefaciens Hen. is found on Abies causing galls.

P. gongrogena Temme causes galls and cankers on willow;

P. fuscescens Sor. parasitizes cultivated Corypha;

P. fuscescens var. sacchari Wak. is on sugar cane.”

On palms occur P. palmicola S. & S., P. palmarum Cke., and

P. pheenicis Grev.

P. inquinans C. & Hark is on eucalyptus in California;

P. stictica B. & C. on sycamore and linden;

P. suffocata E. & E. and P. discosioides E. & E. on roses.

-P. lupini Sor. on Lupinus cotyledons.™

Coryneum Nees. (p. 558)

Acervuli discoid or pulvinate, subcutaneous, erumpent, black,
compact; conidia oblong to fusoid.

Some seventy-five species.

C. modonia (Sacc.) Griff. & Maub. on chestnut=Melanconis
modonia Tul. See p. 281.

C. juniperinum E. on juniper=Exosporium juniperinum.™!

C. beyerinckii Oud.

Acervuli minute, punctiform, black, gregarious; conidia borne
on a parenchymatous pulvinate stroma, stipitate, oblong, ovate,
light olivaceous, 3 to many-septate, slightly constricted at the
septa or not, cells not all of the same size.

Ascospora beyerinckii is said by Vuillemin to be the ascigerous
stage. See p. 236. It is reported as injurious to peaches, caus-
ing blight and shot-hole in California ™? and to apricots, cherries
and peaches in Africa. It is close to and perhaps identical with
Clasterosporium carpophilum.

The acervuli occur as black specks near the centers of the leaf

THE FUNGI WHICH CAUSE PLANT DISEASE 561

spots but since diseased tissue soon drops out they are often diffi-
cult to find. Bark spots are often sterile. Late in the season spores
abound scattered on the surfaces of twigs, especially at rough
places, as near leaf scars. Spores near bud scales penetrate them
with a mycelium and kill the buds or if on bark they enter the
twig and produce dead spots.

C. foliicolum Fuckel.?%

Spots epiphyllous, ochraceous, indefinite; acervuli punctiform,
erumpent; conidia ellipsoid-oblong, 17 x 6-7 yu, 3-septate, con-

pS

SS

Wrse2%64
a NeeuayMlaee drt
SOSH HAY A
PENlys uA eeat
SENNA Y ROT 7
RSS NE aeed

Fic. 378.—C. beijerinckii. Longitudinal section of a pustule. ,
After Smith.

stricted: at the septa, olivaceous, lower cell subhyaline, stalk
subhyaline, 15-20 x 1.25 u.

It is present as a saprophyte on apple leaf spots and causes
cankers on twigs and branches.

C. camellize Mas. is reported on cultivated Camellia.

C. mori Namura causes mulberry twig blight in India.”

The Melanconiacez-Hyalodictye and Melanconiacee-Phzod-
ictye containing only three genera have. no parasitic species of
importance. -

Melanconiaceze-Scolecospore (p. 537)

Conidia cylindric, filiform or suballantoid, hyaline, mostly con-
tinuous.

562 THE FUNGI WHICH CAUSE PLANT DISEASE

Kry to Genera or Melanconiacez-Scolecospore

Conidia allantoid. ...................--. 1, Nemospora.
Conidia bacillar to filiform
Conidia fasciculate at the apex of the
conidiophores. . ............-+05+- 2. Trichodytes.
Conidia solitary
Masses white or pale, foliicolous; conidia
filiform. ...........00 200s e ee eee 3. Cylindrosporium, p. 562.
Masses gray or dark, usually ramicole;
conidia faleate.................- 4, Cryptosporium, p. 564.
Masses bright-colored, saprophytic;
conidia falcate................-. 5. Libertella, p. 564.

Cylindrosporium Unger

Acervuli subepidermal, white or pallid, disciform or subeffuse;
conidia filiform, continuous, hyaline, straight or curved.

About one hundred species of
parasites, several of them of con-
siderable economic importance.

C. mori Berl. on Morus=Myco-
spheerella morifolia. See p. 249.

C. castanicolum (Desm.) Berl.
on Castanea=Mycospherella macu-
liformis. See p. 249.

C. padi Karst.*220

Hypophyllous; spots angular, sub-

i ae fuscous; acervuli subepidermal caus-
Fic. 379-—C. padi, scotion of acer- ing elevations; conidia curved,
cylindric, 48-60 x 2 yu; conidio-

phores minute, produced in great abundance.

This is the cause of the most common, familiar, widespread and
destructive shot-hole disease of the cherry and plum. When on
the peduncles the fruits are dwarfed and ripen unevenly. The
diseased leaf tissue usually falls away, resulting in ‘‘shot-holes.”
Acervuli abound.

Arthur found a Phoma associated with this fungus and later
asci in the same pycnidia. He believed these forms all con-

Wet
,

LY h PENS <
ES

THE FUNGI WHICH CAUSE PLANT DISEASE 563

nected but confirmation of such conclusion has not been ad-
duced. Connection with Coccomyces has also been reported.‘

C. tubeufiana All., also on Prunus is closely like C. padi.

C. pomi Brooks.?!1-212

Acervuli pallid, subeffuse, at first subepidermal, then erumpent;
conidia granular, filiform, straight or
flexuose, 15-80 x 2-2.5 p.

It is reported as common from
New Hampshire to Virginia and Michi-
gan on apples of almost all varieties,
causing small, dry, sunken, brown fruit
spots; a disease which had hitherto
been referred to a variety of causes.

The fungus was studied in numerous Fyq. 380.—Cylindrosporium
culture media and its pathogenicity was Pom. pre SeEmnHn =
proved by inoculations. Brooks.

C. chrysanthemi E. & D.*

Spots subindefinite, 1 cm. or more broad, black; acervuli innate,
amphigenous, 100-170 u; conidia fusoid straight, 50-100 x 3-4.5n.

The fungus causes dark blotches on the leaves of chrysanthemum.

C. clematidis E. & E.

Spots amphigenous, reddish-brown, round or subangular, 1-3 y;
acervuli comparatively few, epiphyllous, immersed, scattered; co-
nidia fusoid-linear, 75-80 x 2.5-3 , somewhat curved, exuding in a
white mass. It causes leaf spot of Clematis.” Later is described
a variety jackmanii which differs from the species in the acervuli
not being confined to the spots, which are less definite, and exud-
ing a black mass of spores which are themselves hyaline.

C. humuli E. & E.

Spots amphigenous, mostly hypophyllous, small, angular, limited
by the veinlets, rusty brown; acervuli minute, black, amphigenous;
conidia nearly cylindrie, granular, 40-50 x 3 u, oozing out in a
white mass.

The cause of leaf spots of hops.”

Other parasitic forms are:

C. saccharinum E. & E. on maple;

C. colchici Sacc. on Colchicum;

C. inconspicuum Wint. on lily;

564 THE FUNGI.WHICH CAUSE PLANT DISEASE

C. orni (Pass.) Pegl. and

C. viridis E. & E. on ash;

C. quercus Sor. on oak;

C. cercosporoides E. & E. on tulip tree.

An unidentified Cylindrosporium is reported from New Jersey
and New York as causing spots of tomato with considerable in-
jury.

It is possible that this was in reality Septoria lycopersici.™ 160

Cryptosporium Kunze (p. 562)

Acervuli discoid-conic, covered by a peridium, erumpent, form-
ing a pseudo-pycnidium from the substratum; conidia fusoid-
falcate, large, continuous, typically stipitate.

Some forty species, chiefly saprophytes.

C. leptostromiforme Kiihn forms black stromata on lupine.

C. minimum Lau. is the cause of a rose stem disease and of
cankers.

Libertella Desmaziere (p. 562)

Acervuli covered, irregularly and tardily erumpent, conidia
filiform, falcate, elongate, continuous.

Some twenty species, chiefly saprophytes.

L. rubra Bon. on Prunus =Polystigma rubrum. See p. 208.

L. ulcerata Mas. causes cankers on fig trees in greenhouses.”!4

Moniliales (p. 479)

The Moniliales differ from the Spheropsidales in the ab-
sence of the pycnidium and from the Melanconiales in their
somewhat loose, separate hyphe, not innate and closely aggregated
as in the Melanconiales. There are genera on the boundaries
between these orders which are difficult to place, as for example
Coryneum, some species of which are often put in Helmin-
thosporium; Vermicularia which sometimes is confounded with
Volutella, etc.

The order is one of very great diversity and contains a multitude
of forms. Many are only saprophytes while some are aggressive
parasites.

THE FUNGI WHICH CAUSE PLANT DISEASE 565

Key To Famiuirs or Moniliales
Hyphe in more or less loose cottony

masses
Hyphe and conidia clear or bright
colored...............0...0000, I. Moniliaces, p. 565.
Hyphz and conidia typically both dark;
one or the other always dark..... II. Dematiacee, p. 594.

Hyphe compactly united or forming a
globose to cylindric body which is
often stalked
Hyphal body cylindric to capitate,
stalked, i. e., a synnema or cory-
MUM oct eben tel resin. Gals III. Stilbacez, p. 632.
Hyphal body more or less globose,
sessile, i. e., a sporodochium ..... IV. Tuberculariaces, p. 638.

Moniliaceze

Hyphz hyaline or bright colored, more or less fragile, lax, not
cohering in fascicles; conidia concolorous, hyaline or bright colored.

Key To Sections or Moniliacee
Conidia globose, ovate, oblong or short-

cylindric
Conidia continous. .................... 1. Amerospore, p. 565.
Conidia two-celled.................... 2. Didymospore, p. 585.
Conidia three or more-celled............ 3. Phragmosporea, p. 588.
Conidia muriform. .................... 4. Dictyospore, p. 592.
Conidia cylindric, spiral or convolute,
usually septate. ................200. 5. Helicospore.

Conidia of several stellately grouped cells.. 6. Staurospore, p. 593.

Moniliaceze-Amerospore
Conidia continuous, globose or ovoid to short cylindric.

Key to Groups or Moniliacee-Amerospore

Hyphe very short, or obsolete, little dif-
ferent from the conidia
Conidia not in chains................ 1. Chromosporiee, p. 566.
Conidia in chains................... 2. Odsporee, p. 567.

566 THE FUNGI WHICH CAUSE PLANT DISEASE

Hyphe elongate and distinct from the
conidia
Conidiophores simple or little branched,
apically swollen
Conidia solitary..................
Conidia in heads
Conidia not in chains...........
Conidia in chains...............
Conidiophores much-branched, conidia
not in heads
Conidia borne irregularly on simple
or branched but not inflated or
verticillate conidiophores. . ....
Conidia borne on _ verticillately
branched conidiophores. .......
Conidiophores with inflated nodes upon
which clusters of conidia are borne

. Hartigiellez, p. 570.

. Cephalosporiez, p. 570.
. Aspergillez, p. 572.

. Botrytidex, p. 574.
. Verticilliz, p. 583.

. Gonatobotrytidee.

Chromosporiez (p. 565)

Hyphe short or obsolete, conidia not in chains.

Key to Genera or Chromospories

Conidia solitary, at least not capitate
Saprophytic
Hyphe almost none
Conidia separate................
Conidia joined in twos or threes,
not catenulate..............

Hyphz very short, branched, septate 3.

Entomogenous.
Phytogenous
Tn fungi
Conidia ovoid, smooth... ........
Conidia globose, verrucose

es

Tn leaves, hyphe vermiform-tortuous 7.

Conidia capitate; hyphz lacking; biophil-

. Chromosporium.

. Selenotila.
Coccospora.

. Massospora.

. Myceliophthora, p. 567.

. Coccosporella.
Ophiocladium, p. 567.

. Glomerularia.

THE FUNGI WHICH CAUSE PLANT DISEASE 567

Myceliophthora Costant (p. 566)

Sterile hyphe creeping, simple or somewhat branched, bearing
conidia at the apex; conidia solitary,
acrogenous, ovoid.

A single species M. lutea Costant.
causes disease of cultivated mush-
rooms in France.?43

Ophiocladium Cavara (p. 566) MY) aes
Fertile hyphae fasciculate, tor- @AT7 VK SK LAX

tuose; conidia acrogenous, ellip- Fc. 381.—O. hordei acervulus and
tie spores. After Cavara.

Two species of which one, O. hordei Cav., parasitizes barley.

Odsporeze (p. 565)
Hyphe short or obsolete, conidia in chains.

Key To GENERA oF Oésporee -

Conidial chains arising in the hyphe

Conidial branches simple, arcuate. ...... 1. Malbranchea.
Conidial branches dichotomous, not
arcuate..............5. sR ann aie 2. Glycophila.
Conidial chains arising at the apex of the
hyphe

Conidia globose, elliptic, or ovate
Conidia all of equal size
Sterile hyphe very short or none... 3. Odspora, p. 568.
Sterile hyphez evident, rarely none
Conidia not connected by an

isthmus
Growing within the substratum
Haustoria none. ............ 4. Monilia, p. 568.
Haustoria present........... 5. Oidiopsis.
Growing on the surface of living
plantsis 24 Sdcnswe axles ales 6. Oidium, p. 569.
Conidia connected by an isthmus. 7. Pepalopsis.
Apical conidium larger............... 8. Halobyssus.

Conidia fusoid, acute at each end....... 9. Fusidium, p. 568.

568 THE FUNGI WHICH CAUSE PLANT DISEASE

Conidia cylindric or cuboid
Hyphe nearly obsolete; conidia cylin-

OPCs. oe taeeekeu ee cath es hess 10. Cylindrium.
Hyphe distinctly present
Conidia cylindric. ............-+.- 11. Polyscytalum.
Conidia cuboid...............-.5 12. Geotrichum.

Odspora Wallroth (p. 567)

Fertile hyphz short, sparingly branched,
slender; conidia catenulate, globose to ovoid,
hyaline or dilute-colored.

Over one hundred species, chiefly saprophytes.

O. scabies Thax.?® 217 219224

Vegetative hyphe rarely 1 » thick, curved ir-
regularly, septate or falsely septate, branching;
aérial hyphe at first white, then grayish,
evanescent, breaking up into bacteria-like
spores.

Isolation and inoculation in pure culture by
Thaxter showed this to be the cause of the
a Foiety Pn sha common American form of scab of Irish potato,

beet, turnip, etc.

O. abietum Oud. causes defoliation of firs in Europe.”

Fusidium Link (p. 567)

Hyphe short, simple, not well differentiated from the conidia
which are fusoid, catenulate, acute at the ends, hyaline or dilute-
colored. In part =Nectria. See p. 201.

A poorly understood genus of over 50 species.

F. candidum Link. on various trees=Nectria ditissima. See
p. 208.

Monilia Persoon (p. 567)

Hyphe erect, branched, forming a dense mycelial felt, which
produces numerous conidiophores; conidia catenulate, hyaline or
light-colored, ovate or lemon shaped. In part=Sclerotinia. See
p. 136.

Some fifty species.

THE FUNGI WHICH CAUSE PLANT DISEASE 569

M. fructigena Pers. on stone and pome fruits=Sclerotinia
fructigena. See p. 139.

M. cinerea Bon. on stone and pome fruits=Sclerotinia cinerea.
See p. 187.

M. cinerea Bon. on Prunus padus=Sclerotinia padi. See p. 140.

M. cinerea Bon. on Vaccinium oxycoccus=Sclerotinia oxycocci.
See p. 140.

M. laxa A. & R. on apricots=Sclerotinia laxa. See p. 137.

M. linhartiana Sacc. on medlars and quinces ” =Sclerotinia
linhartiana. See p. 141.

M. crategi Diedicke on Crategus =Sclerotinia crategi. See
p. 148.

M. seaveri Reade on Prunus =Sclerotinia seaveri.* “? See
p. 140.

M. fimicola Cast. & Matr. is a parasite of mushrooms, Clitocybe
and Pleurotus.

Oidium Link (p. 567)

On the surface of living leaves; hyphe branched, white, bearing
erect, simple conidiophores with catenulate, ovoid conidia.

About fifty species.

These conidial fungi in the main belong to the Erysiphales
though some forms are placed in Oidium which clearly do not
belong to that ascigerous order. Salmon states that there are
some forty-four apparently Erysiphaceous Oidiums listed; but
that twenty-five of these grow on plants known to be the hosts
of ascus bearing Erysiphacee.

O. fragarie Harz.=S. humuli. See p. 175.

O. leucoconium Desm.=S. pannosa. See p. 176.

O. balsamii Mont.=E. polygoni. See p. 177.

O. ambrosie Thiim.=E. cichoracearum. See p. 178.

O. monilioides Link.=E. graminis. See p. 179.

O. tuckeri Berk.=U. necator. See p. 181.

O. crategi Grogn.=P. oxyacanthx. See p. 183.

O. farinosum Cke.=P. leucotricha. See p. 184.

The following may also be mentioned:

O. erysiphoides Fr. on hop, clover, cucumber, etc.;

O. chrysanthemi Rab. on chrysanthemums,;

570 THE FUNGI WHICH CAUSE PLANT DISEASE

O. mespilinum Thiim on Mespilus;

O. tabaci Thiim on tobacco;

O. verbenz T. & B. on Verbenas.

O. quercinum Thiim has becn reported as the cause of much
injury to oaks in Europe since 1907. The identity of the Oidium
causing the epidemic is, however, much questioned. By some it is
regarded as a stage of Microsphera alni, by others it is set up
under a separate name as O. alphitoides G. & M.??> 2%

Hartigiellez (p. 566)

One genus, Hartigiella Sydow. The species H. laricis (Hart.)
Syd. causes fall of needles of larch.**®

Cephalosporiez (p. 566)
Hyphe elongate; conidia in heads.

Key To Genera OF Cephalosporier

Conidia globose or oblong
Conidia sessile on the head or nearly so
Fertile hyphe inflated at apex
Apical vesicle globose-inflated
Conidia sessile, not mucus-covered
Vesicle verrucose or muriculaté

Fertile hyphe simple. ....... 1. G@docephalum.
Fertile hyphe sigmoid, much -
branched. ............. 2. Sigmoideomyces.
Vesicle hexagonally areolate.... 3. Rhopalomyces.

Conidia on stalks, mucus-covered. 4. Gliocephalus.
Apical vesicle clavate or lobed
Vesicle disk-shaped, _ stellate-
lobed ses5si en eaavewe ene 5. Coronella.
Vesicle clavate or subpalmate.... 6. Buseella.
Fertile hyph not inflated at apex
Conidial head covered with mucus

Fertile hyphe simple. ........... 7. Hyalopus.
Fertile hyphe with verticillate
branches at tip............. 8. Gliobotrys.
Conidial head without mucus
Fertile hyphe with one head

Conidia not separating. ........... 9. Papulospora.

THE FUNGI WHICH CAUSE PLANT DISEASE 571

Conidia separating

Head elongate. ............... 10. Doratomyces.
Head globose or slightly clavate
Sterile hyphe scanty. ....... 11. Haplotrichum.
Sterile hyphe long, decum-
Dente iene ee ee ee 12. Cephalosporium, p. 571.

Fertile hyphz with 2 to several heads
' Conidia upright on verticillate
conidiophores. ............. 13. Coemansiella.
Conidia in more definite heads
Fertile hyphz simple, with 3 to
several heads of conidia on

SPINES): cesoncahaiadwauez ea ws 14. Botryosporium, p. 571.
Fertile hyphe several times 2 to
BD: ss wd apkierds dichern abe’ 4,2 be We 15. Trichoderma.
Conidia borne on little stalks or sterig-
mata
Fertile hyphe simple.............. 16. Corethropsis.
Fertile hyphe verticillate branched... 17. Spicularia.
Conidia short cylindric

Conidia without mucus. ............. 18. Cylindrocephalum.
Conidia covered with mucus. ........ 19. Acontium,

Cephalosporium Corda

Hyphe creeping, conidiophores short, erect, not apically swollen.
Conidia spherical or ovate, hyaline or slightly colored.

The small spored condial forms often associated with Fusarium
(microconidia) belong to this form-genus.

Botryosporium Corda

Hyphe assurgent, simple or forked, elongate, irregularly later-
ally branched; fertile branches simple, with three or more short
apical branches which end in heads of conidia; conidia globose to
ovate.

A genus of only about ten species.

B. diffusum (Grev.) Cda. has been reported as parasitic on Cas-
uarina;

B. pulchrum Cda. on wheat and radish.

B. longibrachiatum (Oud.) Maire on various green-house plants.

572 THE FUNGI WHICH CAUSE PLANT DISEASE

Aspergillez (p. 566)
Hyphe well developed; conidia in heads, catenulate.

Key to Genera oF Aspergiller

Fertile hyphz inflated at apex
Fertile hyphz simple or nearly so
Sterigmata of apical vesicle none or

simple
Conidia terminal on sterigmata. .... 1. Aspergillus, p. 572.
Conidia lateral and terminal on ster-
WpM ate . ose eee ee ees 2. Dimargaris.

Sterigmata verticillately branched.../ 3. Sterigmatocystis, p. 573.
Fertile hyphz dichotomous, branches
CUIVEIS 6 nctitcc dace ech hee Pak cee 4. Dispira.
Fertile hyphz little or not at all inflated
Fertile hyphe verticillately branched at
tip
Tips equally verticillate; conidia doli-
LOF His xs eivicioti a BE oneal wea 5. Amblyosporium.
Tips unequally verticillate; conidia
globoid
Conidia without mucus
Conidiophores slender............. 6. Penicillium, p. 573.
Conidiophores swollen, conidia en-
closed in mucus................ 7. Gliodcladium, p. 574.
Fertile hyphz not verticillate at tip. .... 8. Briarea.

Aspergillus (Micheli) Link

Hyphe effused, creeping; conidiophores erect, simple, capitate;
conidia catenulate; sterigmata none or indistinguishable from the
conidia.

The conidia are often found, the asci but rarely.

‘A. fumigatus Brizi, is held responsible by Brizi2’ for pathological
changes in wheat seed which rendered them incapable of germina-
tion.

. A. ficuum (Hen.) Weh. and A. pheenicis (Cda.) Lind. occur on
gs.

THE FUNGI WHICH CAUSE PLANT DISEASE 573

Sterigmatocystis Cramer (p. 572)

As in Aspergillus but with the sterigmata branched in whorls
at the apex.

S. niger Van Tiegh.

Hyphz slender, conidiophores erect, 800-1000 x 11-16 y, thick-
walled, hyaline or dark above, the apical globose swelling black;
basidia 40 y» long, radiately arranged, sterigmata obclavate, 8-

Fic. 384.—Aspergil-
lus. From Strass-
burger et al., Text

Corda. Book of Botany.

10 » long; conidia globose, 3.4—4.5 », minutely verrucose, violet-
brown, catenulate. On tobacco.
S. ficuum (Reich.) Hen.
Conidia globose, 3.8 wu, dark violet, thick-walled, smooth.
In the fruits of figs in Asia Minor and United States.
S. luteo-nigra Lutz. is injurious to cacao in the tropics.

Penicillium Link (p. 572)

Hyphe creeping; conidiophores erect, apically irregularly ver-
ticillate-penicillately branched; conidia catenulate, spherical, or

574 THE FUNGI WHICH CAUSE PLANT DISEASE

elliptical, hyaline or variously colored. For the ascigerous stage
see page 167.

The conidial stages of many Penicilliums have been given
searching investigation and comparative study by Thom.?%

P. glaucum Lk.

Hyphe effused, creeping, septate, interwoven, white, conidio-
phores penicillate, branches single or in pairs, erect, forked; conidia
globose to broadly elliptic, smooth, hyaline,
with a tinge of green, 4 u.

It is the cause of rot of ripe oranges, lemons,
apples, ete.

P. italicum Weh. is described as a wound
parasite on oranges by Massee.™ It is very
similar in appearance to P. glaucum but a
Fic. 385.—Penicillium. little greener; conidia elliptic-oblong, 7-9 x 4 un.

sili vic P. digitatum (Fr.) Sace.

‘Similar to the preceding species in habit but the conidia are
white in mass, 4-6 4. Often associated with, and similar in effects
to P. glaucum.

P. olivaceum Weh. is found on citrous fruits;

P. luteum Zuk. on apple.

An undetermined species is reported as the cause of a white dry
rot of sweet potatoes.3°

Various other species of the genus occur on fruits and vegetables
causing their decay.

Gliocladium Corda (p. 572)

Hyphe effused, spreading; conidiophores and conidia as in
Penicillium but the conidia surrounded by a mass of mucus.
A genus of only about ten species.

-G agaricinum C. &. M. arrests growth and breaks the pilei of
mushrooms.

Botrytidee (p. 566)

Conidiophores elongate, simple or branched but not inflated,
and the branches not verticillate; conidia borne variously, globose
or ovate to elliptic. ;

THE FUNGI WHICH CAUSE PLANT DISEASE 575

Key To GENERA OF Botrytide

Conidia smooth or scarcely roughened
Saprophytic or apparently so, often real
parasites
Conidia typically pleurogynous
Fertile hyphe 2 to several-furcate.. .
Fertile hyphz simple or nearly so
Conidia globose or ellipsoid. .....
Conidia short cylindric. .........
Conidia acrogenous or pleurogynous
Some intermediate joints of the hy-
phe swollen and denticulate,
conidia-bearing. ..............
Intermediate joints equal
Conidia-bearing hyphe of two sorts,
the upright alone denticulate
Conidia-bearing hyphe of one sort
Fertile hyphe simple or nearly so
Hyphe not denticulate;
conidia solitary
Hyphe forming a crust-like
stratum. ............
Hyphz loose, cobwebby. . .
Hyphz denticulate; conidia
usually grouped
Hyphe everywhere denti-
culate, bearing conidia
only at tip. ..........
Hyphz denticulate or pro-
liferous at tip alone
Apex denticulate, many-

Apex _inflated-ampulli-
form, 1-spored......
Fertile hyphz branched
Conidia globose to ovoid
Both sterile and fertile
hyphe procumbent
Sterile hyphz intracellu-

1.

2.
3.

10.

Haplaria.

Acladium.
Cylindrotrichum.

. Physospora.

. Blastomyces.

. Hyphoderma.
. Acremonium, p. 577.

. Xenopus.

. Rhinotrichum.

Olpitrichum

. Hartigiella.

576 THE FUNGI WHICH CAUSE PLANT DISEASE

Sterile hyphz superficial

Fertile hyphz vaguely
branched

Conidia acro-pleuro-

Conidia on a one-
sided sympo-

Fertile hyphe dichoto-
mous; conidia ac-
rogenous on spine-
like branches... ..

Fertile hyphe erect or as-
cending
Conidia solitary acrogen-
ous

Fertile hyphe spiny-
branched at apex.

Fertile hyphe not
spiny-branched. . .

Conidia loosely grouped
about the apex

Conidia not involved
in mucus

Conidia on inflated
muriculate apices
Apices not muricu-
late or inflated.

Conidia involved in
MUCUS. ........-.

Conidia fusoid to cylindric
Fertile hyphe mostly pro-

Fertile hyphe erect or as-
cending
Conidia fusoid on the
upper side of curved
branches...........
Conida acrogenous
Conidia-bearing
branches terete. . .

12.

13.

14,

15.

16.

17.

18.

19.

20.

Sporotrichum, p. 577.

Monopodium.

Langloisula.

Plectothrix.

Monosporium.

Phymatotrichum.
Botrytis, p. 578.

Tolypomyria.

Sporotrichella.

21. Martensella.

22.

. Cylindrophora.

THE FUNGI WHICH CAUSE PLANT DISEASE 577

Conidia-bearing
branches ellipsoid 23. Cylindrodendrum.

Biogenous
Conidia smooth
Catenulate. ..............0000004. 24. Ovularia, p. 582.
Bolitaty. . ccc ceccccccisweveavaes 25. Ovulariopsis, p. 582.
Conidia densely spiny............... 26. Ramulaspera.

Conidia muricate or tuberculose-stellate
Conidia globose
‘Conidia merely muricate

Hyphe loose, cobwebby. .......... 27. Sepedonium.
Hyphez woven into a subgelatinous
pellicle. .................000. 28. Pellicularia, p. 382.
Conidia setose at apex as well as muri-
COLE 5hi 5 scene wind node maer neh Sead 29. Cheetoconidium.
Conidia tuberculose-stellate............ 30. Asterophora.

Acremonium Link (p. 575)

Hyphe subsimple, procumbent; conidiophores simple, short;
conidia solitary, hyaline or light colored,
oval to ellipsoid.

A genus of some ten species.

An undetermined species is recorded by
Humphrey 7 "5 as causing disease of cucum-
bers in Massachusetts.

Sporotrichum Link (p. 576)

Hyphx widely spreading, much branched;
conidiophores simple, short; conidia solitary or in groups on
separate sterigmata, ovoid or subglobose.

Over one hundred twenty-five species are described, most of
which are saprophytes.

S. poz Pk.

Hyphe creeping, interwoven, branched, continuous or sparingly
septate, variable in thickness, 2.5-6 y, hyaline, forming a loose
cottony stratum; conidia of two kinds; microconidia, globose or
broadly ovate, 4-12 »; macroconidia abundant, elongate elliptic to
ovate elliptic, 1 rarely 2-septate, about three or four times as
large as the microconidia.

Fic. 386.—Acremonium.
After Saccardo.

578 THE FUNGI WHICH CAUSE PLANT DISEASE

The form is an atypical one in
that it produces two kinds of
spores; one kind which is usually

Ul (AK 52m. septate

Heald 2” also Stewart and Hodg-
kiss 2° have described it as the
cause of bud rot of carnations, while
the latter authors also mention it
in connection with a disease known
as “silver top” of June grass in
Fic. 387.—S. pox. 11,Hyphabear- which the panicles wither’ as they

ing conidiophores and macroco-
nidia. 13, Hypha bearing co- expand, though the authors express
nidiophores, end = SuroeoE ne doubt as to its actual causal relation
to the disease. A mite appears to
be the carrier of ‘the spores. Cultural studies and cross-inoculation

showed the fungus form on the two hosts to be identical.

Botrytis (Micheli) Link (p. 576)

Hyphe creeping; conidiophores simple or more or less markedly
dendritic branched, erect, branches various, thin and apically
pointed, thick and obtuse or cristate; conidia variously grouped
at the apex of the branches, never in true heads, continuous,
globose, elliptic or oblong, hyaline or light colored.

In part =Sclerotinia. See p. 136.

A genus of some two hundred or more species, several of them
of great economic importance.

This form-genus contains many parasites on various hosts.
In some instances they are known to include ascigerous stages,
(Sclerotinia), in their life cycle; in others no such relation is known,
though it has often been assumed on quite untenable grounds.
Specific limitations are but poorly understood and the relations
between the various forms and between these forms and the as-
cigerous stages are in a state of much confusion c. f. (p. 137). In
some instances the same conidial stage is claimed by different in-
vestigators as belonging to two distinct ascigerous species, a
manifest impossibility, (e. g., S. fuckeliana and S. libertiana with
B. cinerea.)

THE FUNGI WHICH CAUSE PLANT DISEASE 579

The more prominent forms as described are given below, recog-
nizing that some of them may be co-specific.

B. cinerea Pers.”**°*

Hyphe slender, constricted at septa, gregarious, simple or
sparsely branched, erect, cinereous, conidia globose, pale.

A form which occurs on the grape is usually referred to
S. fuckeliana though there is not entire agreement on this point.
On the grape the Botrytis develops its mycelium in the berries
and produces dense tufts of conidia over their surfaces. The
sclerotia forny within the fruits. Leaves and
canes are also affected. (see p. 140).

On the lily Ward? in a classic study de-
monstrated the parasitism of the fungus show-
ing its action to be dependent upon toxins and
enzymes. The type in this case deviated some-
what from the usual B. cinerea in that its
spores were a little larger than is usual, but it
nevertheless seemed to be this species. No
ascigerous stage was found.

On Cyclamen and Primula Wehmer2** re-
ports a similar case.* The fungus has also a
often been reported on the cultivated gera- Fic. i ae
nium.

On lettuce Humphrey, °°’ Jones, 7° Bailey,2"9 and many others
have reported a greyish mold on the leaves due to a Botrytis
which is often cited as B. cinerea though it appears to form no
ascigerous stage. The affected part of the leaf collapses and is
covered with a conspicuous growth of the conidiophores and coni-
dia. Small sclerotia are produced in considerable abundance
when on artificial media but they, on germination, bear clusters,
dense bushy tufts, of conidiophores. That this form on lettuce
ever produces ascophores is doubtful.

Smith describes a case in which linden stems beginning at the
ground were parasitized by B. cinerea. The bark appeared to be
first. affected and sclerotia formed in the cortical parenchyma.
Similar cases are on record regarding the rose, various conifers,
grape (Brizi) Aesculus, Prunus. In all of these cases the Botrytis
seems to be B. cinerea and without ascophores.

580 THE FUNGI WHICH CAUSE PLANT DISEASE

Numerous studies 24! of the power of B. cinerea to infect growing
tissue have been made with the conclusion that it is a weak parasite
and that to become aggressively parasitic it must first develop
@ vigorous mycelium saprophytically. Attempts to immunize
plants against its attack have been made with partial suc-
cess.?4?

Extensive studies of the condition of sclerotia and conidia forma-
tion by B. cinerea (from grape) were made by Reidemeister.”“*
He concludes that sclerotia form on all media favorable to growth
of the fungus. They are on an average 5-8 mm. in diameter,
smaller under conditions of poor nutriment, high osmotic pressure
or strong transpiration. They are often found in concentric rings
and their formation is induced by the presence of various agents
which inhibit growth. Conidia are formed under condition of
energetic transpiration and on media of high osmotic tension.
Conidia and sclerotia vary inversely jin production. Appressoria
develop on all media where sclerotia grow and are favored by
substances which inhibit growth. Conidia are suppressed by
conditions favoring the formation of appressoria.

B. depredens Cke. is a pest of the sycamore.

B. fascicularis (Cda.) Sacc.® :

Cespitose, minute, brownish; hyphe erect, fasciculate, flexuose,
brown, or semi-pellucid, branches hyaline; conidia in subglobose,
white heads, oblong, large.

' A mold of egg-plants is attributed to this fungus by: Hal-
sted.

An undetermined Botrytis is reported on carnation by Atkinson
and another on Ribes.?44

B. parasitica Cav.

Hyphe cinereous, sparse, erect, inflated at base; conidia ovate,
large, short-pedicillate, on short branches, heads umbellate, hya-
line or dilute, cinereous, 16-20 x 10-13 p.

This is said by Halsted #1 to be the form found on lilies, parti-
cularly the bulbs, in New Jersey. It was first reported by Cavara
in Italy and is widespread and destructive.

B. powonize Oud. 23+ 245) 246

Mycelium in the parenchyma of the host, hyphe erect, 0.25-
1 mm. high, protruding through the stomata, branches spirally:

THE FUNGI WHICH CAUSE PLANT DISEASE 581

arranged, simple, or branched; conidia, numerous, in heads 12-15
» across, oblong or ovate-oblong, 16-18 x 7-7.5 un, hyaline or di-
lute colored.

It is reported as the cause of considerable injury to peonies in
different parts of the United States. The greenish-black flat
sclerotia are found inside the stems.

It is mentioned by Bos ** as parasitic on young peony stems and
on lily-of-the-valley and lilac.

B. longibrachiata Oud.?2” 24

White, sparse, cespitose, 1.5-2 mm. high; mycelium creeping,
branched; fertile hyphz, verticillate, hyaline, much branched
and apically inflated; conidia numerous, hyaline, oval, 4.5-5.5 x
2.5 wb.

It was reported by Thaxter 7? as the cause of stem rot of to-
bacco in the curing house. The affected stems are covered with
white velvety patches of mycelium which soon spread to the
veins.

The same fungus is reported by Aderhold on ferns.”

This is perhaps a form of B. cinerea.

B. douglassi Tub. on fir may be B. cinerea and =Sclerotinia
fuckeliana. See p. 140.

B. citricola Brizi, closely related to B. cinerea, attacks oranges
and citrus fruits resulting in mummies.

B. diospiri Brizi attacks the persimmon fruit near time of ripen-
ing and prevents maturity.

B. patula S. & Ber.?°

Cespitose, minute, greyish-white, spots cottony, suborbicular;
fertile hyphe assurgent, continuous, filiform, branching, panicu-
late; conidia large, globose or globose-elliptic. 30 u in diameter,
light yellow. On raspberries.

B. infestans (Hazsl.) Sacc. is common on hemp in Europe. It
sometimes is associated with Sclerotinia libertiana which has led
some to assume its connection with that fungus; but no such
genetic relation is probable.

B. galanthina Lud. occurs on snowdrops. It is said to belong to
Sclerotinia galanthina, see p. 141, but the asci have not been seen.

Undetermined species are reported on carnations, Ribes and

-mangold.?5!

582 THE FUNGI WHICH CAUSE PLANT DISEASE

Ovularia Saccardo (p. 577)

Hyphe, simple, or sparingly branched, erect, apically simple
or dendritically branched; conidia globose or
ovoid, solitary, rarely in short chains.
Over seventy-five species, all parasites.

O. necans (Pass.) Sacc. produces spots on
quince leaves in Italy and France;
é ._ QO. canegricola Hen. on economic species of
Fic. 389.—Ovularia, Rumex;

After Sorakin. O. armoraciz Fcl. on horseradish;

O. interstitialis B. & Br. and O. grimulana Thiim. on grimrose
leaves;

O. viciz (Frank.) Sacc. on Vicia;

O. corcellensis Sacc. on Primula;

O. alnicola Cke. on Alnus;

O. rosea Fel. on willow;

O. villiana Mag. on lemons;

O. syringe Berk. on lilac.

O. citri B. & F. causes the white rust of lemons in Sieily. ee

A lemon disease in Australia has been credited by McAlpine 25%
to O. citri McAlpine.

O. medicaginis Br. & Cav. is on alfalfa;

O. exigua (W. Sm.) Sacc. on clover.

Ovulariopsis Patouillard & Hariot (p. 577)
Similar to Ovularia, except in the solitary, acrogenous, sub-
clavate conidia.
Sterile hyphx creeping, conidiophores erect, simple, septate, -at
apex with a single 1-celled hyaline, subclavate conidium.

A small genus of leaf parasites, in part conidia of the Erysi-
phacee (Phyllactinia). See p. 187.

O. ulmorica Del. causes a mildew of mulberries.2°4
Pellicularia Cooke (p. 577)

Hyphe creeping, branched, septate, in a subgelatinous pellicle,
conidia sessile.

THE FUNGI WHICH CAUSE PLANT DISEASE 583

A single species. P. koleroga Cke. causes a coffee leaf rot in
India and has been reported by Fawcett ?*° as causing serious leaf
blight of the same host in the West Indies.

Verticilliez (p. 566)

Conidia acrogenous, on verticillate branches of the conidiophore.

Key To GENERA oF Verticillies

Conidia solitary or loosely grouped, not in
chains
Conidia-bearing branches very short, am-
PUNlOFM ones panies sa cng cree 1. Pachybasium.
Conidia-bearing branches terete or longer
Conidia globose to ovoid
Tips of branches clavate, in twos
rectangularly. ................ 2. Verticilliopsis, p. 584.
Tips of branches not as above
Conidia conglutinate into a stra-
TUN Saige eeeeaoste alee hess 3. Corymbomyces, p. 584.
Conidia not conglutinate
Conidia separating readily from

the tipsicsces ve es Ses aes ae 4, Verticillium, p. 584.
Conidia separating with dif-
ficulty from the tips....... 5. Cladobotyrum.

Conidia cylindric or elongate
Conidia-bearing branches or sporo-
phores 1-spored
Sporophores straight. ........... 6. Acrocylindrium.
Sporophores uncinate.. ......... 7. Uncigera.
Sporophores several-spored
Sporophore inflated verrucose at
APEX: ve cei ceaaene wea acids 8. Calcarisporium.
Sporophore incurved, with seriate
conidia below.............- 9. Coémansia.
Conidia capitate or densely spicate, not in
chains
Conidia sessile
Conidia capitate, involved in mucus
Fertile hyphz smooth............. 10. Acrostalagmus, p. 584.
Fertile hyphe asperate. ........... 11. Gleosphera.

584 THE FUNGI WHICH CAUSE PLANT DISEASE

Conidia densely spirally spicate at

BDICES is id nae ciao os ew 12. Clonostachys.
Conidia on small stalks. ............... 13. Sceptromyces.
Conidia in chains.............-....0200- 14. Spicaria, p. 585.

Verticillium Nees (p. 583)

Hyphe creeping; conidiophores erect, verticellately branched ;
conidia borne singly at the apex of the branchlets, globose-ovoid,
hyaline or light colored.

A genus of some seventy-five species, which are in the main
conidia of various species of Hypocreales. See p. 196.

V. albo-atrum McA. is a weak wound parasite of the potato.

Verticilliopsis Cast (p. 583)

Fertile hyphz with verticillate branches, 2 or 3 at each node;
fertile branches clavate; conidia in heads, surrounded by a slime.
A monotypic genus.

V. infestans Cast. infects mushrooms in culture.

Corymbomyces Appel & Strunk (p. 583)

Sterile hyphz creeping; fertile hyphe erect, septate, dichoto-
mous corymbose; conidia ellipsoid, clustered in gelatinous masses
at the apex of the branches.

A single species, C. albus Appel & Strunk. on cacao in Africa.

Acrostalagmus Corda (p. 583)

Hyphe creeping; conidio-
phores erect, septate, richly
verticillately branched; conidia
borne in slimy heads on the
enlarged end of the secondary
branches.

About fifteen species.

Fic. 390.—Cross-section of a vascular A. albus Preu.
ae arene pai inthe Hyphe cespitose, effuse, slen-
der, subangular, continuous or
septate, conidiophores, 200-220 x 1.7-2 u, erect; fertile branches
continuous, straight or curved; conidia in spherical heads, 9-10 u

THE FUNGI WHICH CAUSE PLANT DISEASE 585

in diameter, numerous, minute, elliptic oblong, 3.3-3.4 x 1-1.5 y,
hyaline.

It causes a wilt of ginseng. The vascular bundles are yellowed
and the ducts plugged by the
mycelium. Entrance is apparently
through the leaf scars. The fungus
was isolated by Van Hook 2 and
cultural studies made. In a later
article Rankin 7” has discussed what
appears to be this fungus under the
name A. panax.

A. vilmorinii Gue.?* 2° causes a
disease of China asters and a species
closely related, one of cacao fruits.

Spicaria Harz (p. 584)

Hyphz creeping; conidiophores 7 #8
erect, much branched; conidia apical, Fre. S21 ppereate ig eae of
H Acrostalagmus albus. e
catenulate, ovate or elongate, hyaline Bron barns Inicio coders
or dilute colored. held together at first by a coat
a of slime. After Van Hook.
About ten species.
S. solani Hart. is said to produce effects on the potato much
like those of Fusarium solani.*6
S. colorans v. Hall, the cause of cacao cankers is probably a

conidial stage of Calonectria cremea. See p. 205.

Moniliacee-Didymosporee (p. 565)

Conidia hyaline, or bright colored, 1-septate, ovoid oblong or
short fusoid.

Key to GENERA oF Moniliacee-Didymosporee.

Conidia not in chains
Saprophytic or on fungi
Conidia smooth
Fertile hyphe simple or nearly so
Hyphe inflated at apex or joints
Hyphe denticulate, inflated at
apex; conidia fusoid. ...... 1. Diplorhinotrichum.

586 THE FUNGI WHICH CAUSE PLANT DISEASE

Hyphe inflated at both apex
and joints.. .........-- 2. Arthrobotrys.
Hyphe not inflated
Conidia spirally pleurogynous 3. Haplariopsis.
Conidia solitary, acrogenous
or capitate

Conidia capitate at apex... 4. Cephalothecium, p. 586.
Conidia solitary at apex
Fertile hyphe long. ..... 5. Trichothecium.

Fertile hyphe very short 6. Didymopsis.
Fertile hyphe branched

Branching irregular........... 7. Diplosporium.
Branching verticillate......... 8. Diplocladium.
Branching dichotomous; sterig-
mata subternate.......... 9. Cylindrocladium.
Conidia echinulate; conidial cells un-
OqUAl. cuties steele aeeueas 10. Mycogone, p. 587.
Biophilous
Conidia obliquely beaked.......... 11. Rhynchosporium, p. 587.
Conidia not beaked
Hyphz mostly simple, not spirally
twisted: Ss:0sesseede neaess 12. Didymaria, p. 587.

Hyphe simple, spirally twisted... 13. Bostrichonema.
Conidia catenulate
Fertile hyphe simple, short. ......... 14. Hormiactis.
Fertile hyphe verticillately branched... 15. Didymocladium.

Cephalothecium Corda

Hyphez prostrate; conidiophores erect,
simple, septate, conidia apical, subcapi-
tate, oblong to pyriform, hyaline.

Five species, chiefly saprophytes.

C. roseum Cda,60- 263

Cespitose in subrotund, rose colored
spots, fading with age, byssoid; hyphe
Fic. 302—Spores of Cepha- creeping, branched ; conidiophores erect,

Rastaee. ; simple, continuous, hyaline; conidia
oblong-ovate, constricted at the septum,

capitate, light rose.
It is often found following apple scab gaining entrance through

THE FUNGI WHICH CAUSE PLANT DISEASE 587

the injured cuticle and causing rot. A ring of pink conidiophores
and conidia is formed around the margin of the scab. Inoculation
tests showed the fungus unable to penetrate through sound cuticle
though it readily made entrance through wounds. It has been
occasionally reported on living twigs and leaves and as a common
saprophyte has long been known. The first account of it in America
was from New York *° in 1902 though it was described in 1899 as
injuring pears in Germany.”

Mycogone Link (p. 586)

Hyphe intricately branched; conidiophores
short, lateral; conidia unequally 2-celled, the
upper larger, echinulate.

There are about fifteen species of mycogenous
fungi which are probably conidial stages of Hy-
pomyces. Seep. 200.

M. perniciosa Mag.?5* 2

White throughout, byssoid, deforming the
host; conidiophores short; conidia solitary,
more or less pyriform, almost colorless, 17- ; =
22 x 9-12 yp. Fic. 393.—Mycogone,

It is reported by Mrs. Patterson as the couidiophores and
cause of a mushroom disease in America. cardo.

A verticillium conidial stage was present but
no ascigerous form.

M. rosea Link. also occurs on mushrooms.

Rhynchosporium Heinsen (p. 586)

On leaf spots; hyphz filiform, hyaline, creeping, septate; conid-
iophores erect, with incurved branches, hyaline, apically denticu-
late; conidia short-cylindric, with a short oblique beak, medially
septate, hyaline. A monotypic genus.

R. graminicola Hein. occurs on rye, wheat, and barley in Europe.

Didymaria Corda (p. 586)

Conidiophores simple, conidia borne apically, ovate, hyaline.
About twenty species of leaf parasites.
D. prunicola Cav. produces spots on plum leaves.

-

588 THE FUNGI WHICH CAUSE PLANT DISEASE

Moniliacee-Phragmospore (p. 565)

Conidia hyaline or bright colored, 2 to several-septate, oblong,

fusoid or elongate.

Key To GENERA OF Moniliaceew-Phragmospore -

Fertile hyphe very short and little dif-
ferent from the conidia
Conidia in chains, cylindric or oblong. .
Conidia not in chains
Sporophore 3-celled, upper cell much
Inflated pix io2vse 3 Had de Wakes
Sporophore not inflated, sometimes
obsolete
Conidia ciliate at apex and upper
BOPPUTAS vo siscva- cer arene dics aiene
Conidia not ciliate
Hyphe lacking; conidia not ag-
BIOBATE. «3502 hea anew as
Hyphe distinct; conidia ag-
gregate
Conidia in mucose glomerules.
Conidia in fascicles, not mu-

Fertile hyphe manifest and distinct from
the conidia
Saprophytic
Conidia solitary or at least not capi-
tate
Fertile hyphz simple
Sterile hyphe lacking.........
Sterile hyphe abundant. ......
Fertile hyphe branched
Hyphe verticillately branched. .
Hyphe irregularly branched. . .
Conidia capitate
Fertile hyphe vesiculose at tip...
Fertile hyphe not swollen
Hyphe simple, sterile lacking . .

. Septocylindrium, p. 589.

. Milowia.

. Mastigosporiun, p. 590.

. Fusoma, p. 590.

. Rotaea.

. Paraspora.

. Dactylella.
. Monacrosporium.

. Dactylium.
. Blastotrichum.

. Cephaliophora.

. Dactylaria.

THE FUNGI WHICH CAUSE PLANT DISEASE 589

Hyphe verticillate; sterile hy-

phe present. ............. 13. Mucrosporium.
Parasitic
Conidia mucose-conglobate, allan-
toid, often continuous......... 14, Allantospora.

Conidia not mucose-conglobate
Conidia ovate-cylindric or elon-
gate, often catenulate. ...... 15. Ramularia, p. 590.
Conidia obclavate-pyriform....... 16. Piricularia, p. 591.

Septocylindrium Bonardin (p. 588)

Conidiophores very short, scarcely distinct from the conidia,
or in parasitic species distinct but short and inflated or dentic-
ulately sublobate at the apex; conidia oblong or cylindrical, one
to many-septate, catenulate, the chains often branched.

About thirty species, a few of them of economic impor-
tance.

S. areola (Atk.) P. & C.766 267

Spots amphigenous, pale, becoming darker in age, 1 to 10 mm.,
angular, limited by the veins of the leaf, conidiophores amphig-
enous, fasciculate, sub-
nodose, branched or not,
several times septate,
hyaline, 25-75 x 4-7 yp;
conidia oblong, usually
abruptly pointed at the
ends, catenulate or not,
14-30 x 4-5 yu, hyaline.

Leaf spots are pro-
duced on cotton. The Fic. 394.—S. areola. After Atkinson.
conidia and stalks are so abundant on the undersides of spots as
to give them a frosted appearance.

S. rufomaculans (Pk.) P. & C.

Spots numerous or confluent and even covering the entire leaf,
reddish; conidiophores very short, hypophyllous, cespitose; conidia
catenulate, variable, ellipsoid-oblong to cylindric, hyaline, 8-16 x
3-4 py.

It is somewhat injurious on buckwheat in Americ

on 268

590 THE FUNGI WHICH CAUSE PLANT DISEASE

S. radicicolum Aderh 2“ is reported by Aderhold as the cause of
death of roots of Prunus and Pyrus.

Mastigosporium Riess (p. 588)

Conidiophores short, stipitate, continuous, hyaline, conidia fu-
soid, large, 3-septate, hyaline, with apical and subapical bristles.
A small genus in part =Dilophia.

Fusoma Corda (p. 588)

Mycelium obsolete or poorly developed; conidia innate, fusiform
separate.
F. parasiticum Percival, causes a wilt of hops.”

Ramularia Unger (p. 589)

Conidiophores fasciculate, simple or with short, scattered
branchlets, often flexuose, nodulose, or denticulate towards the
apex, hyaline or light colored; conidia acrogenous or acropleuro-
gynous on the denticulations, hyaline, sometimes subcatenulate,
oblong, cylindric, typically many-septate.

About three hundred species. In part =Mycospherella. See
p. 243.

R. tulasnei Sacc. on strawberry =Mycospherella fragarie. See
p. 244.

R. armoracie Fcl.”

Spots amphigenous, subochraceous becoming gray; conidiophores

fasciculate, continuous, subsimple, 40-50 x
2.5-3 4; conidia rod-shaped, obtuse, hyaline,
15-20 x 3-4 p.

On horseradish causing leaf spots.

R. taraxaci Karst.

Hypophyllous, spots purple-margined, hyphe
35-45 x 2-3 u, spores bacillar, simple, straight,
hyaline, 18-30 x 2-3 p.

Fig. 395.—R. armora-

ciz. After Sac- On dandelion.

cardo. R. spinacie Nip. is on spinach;

R. bete Rost. on beet;

R. necator Mas. on cacao;

THE FUNGI WHICH CAUSE PLANT DISEASE 591

Rs geranii (West.) Fcl. on cultivated geraniums

R. primule Thiim.

Spots rounded-angular, subochraceous, emarginate; conidio-
phores amphigenous, 50-60 x 5 yu, continuous, somewhat denticu-
late, rarely branched; conidia fusoid-cylindric, 20-30 x 3-6 u, con-
tinuous or l-septate. On Primula.”

. lactea (Desm.) Sacc. is on violets;

. heraclei (Oud.) Sacc. on cultivated Heracleums;

. onobrychidis P. & D. on leaves of sainfoin.

. cynare Sacc. causes loss of artichokes in France and Africa.
. coleosporii Sacc. is on sweet potato in Porto Rico.”

. modesta Sacc. is recorded for the strawberry.

. narcissi Chit. and R. vallambrosz Br. & Cav. cause disease
of leaves and stalks of Narcissus.”

R. geeldiana Sacc. kills twigs of coffee.

PrP WRWnDW

Piricularia Sacc. (p. 589)

Conidiophores simple, rarely branched,
conidia obclavate to pyriform, 2 to many-
septate, solitary acrogenous, hyaline.

A small genus of parasites.

P. grisea (Cke.) Sacc.?-?”8 produces
pallid or water-soaked, spots on culms
and leaves, with age greyish; conidio-
phores in clusters of two or five from
the stomata, simple or rarely sparingly
branched, greyish, septate; conidia sin-
gle, terminal in scorpioid cymes, ovate, . 4_—-I DS
2-septate, 24-29 x 10-12 ux.

It causes death of rice plant tissue and 5, 396:—Piricularia prisens
the disease called ‘‘blast.” If affected 4, conidiophores. b, ger-
leaves or stalks be placed in a damp at- ee PORE ce
mosphere for about a day a delicate
greyish fungus, the sporing mycelium appears. The fungus grows
well in culture and applied to the rice plants gives rise to the
typical disease spots. This species was originally described on
Digitaria sanguinalis and the form on rice has been called

592 THE FUNGI WHICH CAUSE PLANT DISEASE

P. oryze; but morphological characters and inoculation experi-
ments indicate their identity on various other grasses.

P. caudata A. & S. occurs on cacao.

To the Moniliacez-scolecospore belongs only one genus:

Cercosporella Saccardo

Hyaline throughout; conidiophores simple or branched; conidia
filiform, many-septate. Distinguished from Cercospora only in
color. The genus contains some seventy species
of parasites.

C. persicze Sacc.?”4

Conidiophores cespitose, on discolored areas,
filiform, 2 to 3-branched, continuous; conidia
40-60 x 1-5 y, torulose.

The conidia develop in abundance on the
lower sides of leaf spots of peach causing a
frosty mildew.

C. narcissi Boud. occurs on Narcissus;

C. inconspicuus (Wint. & Hohn) on lily.

C. pastinace Karst.
Fie. 397—C. per- Spots amphigenous, fuscus or whitish; conidia
sicse. After Sac- filiform, somewhat curved, slender, attenuate,
50-90 x 2 wy.

On parsnip and other Umbelliferee.

C. albo-maculans E. & E.

Spots orbicular, white, dark-margined, conidiophores amphige-
nous, cespitose, 8-12 x 2 yw, hyaline, continuous; conidia cylindric,
40-68 x 2-2.5 yp, straight or curved, 3-septate.

A common cause of pale spots on turnip leaves.

Moniliacez-Dictyosporez (p. 565)

Conidia hyaline or bright colored, muriform, globose, ovoid
or cubic.

Key To Genera or Moniliacee-Dictyosporese
Saprophytic
Hyphe much-branched; conidia elliptic
or globose, cells uniform........... 1. Stemphyliopsis.

THE FUNGI WHICH CAUSE PLANT DISEASE 593

Hyphe little-branched; conidia six-lobed
and sarcineform, central cell larger,
colored, lobes hyaline... ........... 2. Synthetospora.
Pras tiC: ccs chases eau sees ra yeraumers 3. Hyalodema, p. 593.

This group contains but one important pathogen, Hyalodema
evansii Mag., recently described by Magnus ** on Zizyphus in
Africa.

The Moniliacee-Helicospore contain no important parasites.

Moniliacez-Staurospore (p. 565)

Conidia hyaline or bright colored, stellate, radiate or forked,
septate or continuous.

Key To Genera or Moniliacee-Staurospore

Hyphz lacking; conidia trident-shaped. ... 1. Tridentaria.
Hyphe present
Conidia globose to cylindric, permanently
attached to 2 or 3 divergent sterig-
Matas sie sseines save van ccetegervn 2. Tetracladium.
Conidia themselves stellate or radiate
Conidia bilobate-forked; lobes parallel,

contiguous. ..........6....00 eee 3. Pedilospora.
Conidia narrowly digitate............ 4. Prismaria.
Conidia 3 to 4-radiate
Conidia ciliate at the apex......... 5. Titea, p. 593.
Conidia muticate
Conidia 3-radiate............... 6. Trinacrium.
Conidia 4-radiate
Fertile hyphe very short, simple 7. Tetracium.
Fertile hyphe branched....... 8. Lemonniera.

Titeze Saccardo

Conidiophores simple, continuous; conidia subradiately 4 to 5-
celled, the cells unequal in size.

A small genus of little economic importance.

T. maxilliformis Rost. has been found on the roots of clover in
Denmark.”

bud THE FUNGI WHICH CAUSE PLANT DISEASE

Dematiacee (p. 565)

Hyphe dark or black, cobwebby, loose, usually rigid, not coher-
ing in definite fascicles; conidia typically dark and concolorous,
but sometimes the hyphz are dark and conidia clear, or the conidia
dark and the hyphe clear. This family parallels the Moniliaceze
and certain intermediate forms must be sought in both.

Key to Sections or Dematiacere

Conidia globose, ovate, oblong or short

cylindric
Conidia continuous. .................. 1. Amerospore, p. 594.
Conidia 2-celled. .............200eeeee 2. Didymospore, p. 601.
Conidia 3 or more-celled. .............. 3. Phragmospore, p. 608.
Conidia muriform.................0.0- 4. Dictyospore, p. 615.
Conidia long, filiform or vermicular....... 5. Scolecospore, p. 625.
Conidia cylindric, spiral or convolute, typi-
cally septate. . 22... cece cece eee 6. Helicospore.

Conidia. of several stellately grouped cells... 7. Staurospore.

Dematiacez-Amerospore

Conidia continuous, globose to oblong.

Key To SuBraMILies or Dematiacese-Amerospore.

Conidiophores very short, scarcely distin-
guishable from the mycelium

Conidia borne singly. ................. 1. Coniosporiez, p. 595.
Conidia catenulate. ...............0005 2. Torulee, p. 595.
Conidia in heads or racemes............ 3. Echinobotryez.
Conidiophores manifest and distinct from
the mycelium and spores
Conidia dark, rarely subhyaline
Conidia not in chains
Conidia capitate. ................. 4. Periconier, p. 597.
Conidia verticillate, or at least lat-
OTA scan wae naniea tke 5. Anthriniex.

Conidia borne singly on short
lateral branches............. 6. Trichosporiee, p. 598.

THE FUNGI WHICH CAUSE PLANT DISEASE 595

Conidia solitary, acrogenous....... 7. Monotosporee, p. 600.
Conidia in chains................... 8. Haplographiee, p. 600.
Conidia hyaline

Conidia acrogenous on short heteromor-
phic conidiophores at the lower
part or bases of erect hyphz

Conidia single or catenulate. ....... 9. Sarcapodiez.

Conidia in heads.................. 10. Myxotrichellez.
Conidia on hyphz of the same kind

Conidia in heads.................. 11. Stachylidiez.

Conidia in chains................- 12. Chalariez.

Conidiosporiez (p. 594)

Conidia not catenulate, conidiophores short.

Key to Genera oF Coniosporiez

Conidia spherical, elliptic or discoid...... 1. Coniosporium, p. 595.
Conidia elongate. ............0.0 eee ee eee 2. Fusella.

Coniosporium Link
Hyphe very much reduced; conidia dark,
globose, ovoid or discoid, borne on short hya-

line conidiophores. i. B06. Beale
About eighty-five species, chiefly saprophytes. ~ sporium. After

C. onobrychidis Mag. occurs on sainfoin; Saccardo.
C. filicinum Rost. on Pteris and other ferns.
Toruleze (p. 594)
Conidia in chains.
Key to Genera oF Torulee
Conidia of two sorts, macroconidia catenul-
ate ,

Microconidia glomerate.............-+- 1. Heterobotrys.

Microconidia interral, catenulate. ...... 2. Thielaviopsis, p. 5£6.
Conidia all alike

Hyphz dark

Chains breaking up readily
Conidia globose or ovoid........... 3. Torula, p. 597.

596 THE FUNGI WHICH CAUSE PLANT DISEASE

Conidia clavate...........-0+-++4+5 4, Gongromeriza.
Chains breaking up with difficulty
Chains curved.............--+-++: 5. Gyroceras.
Chains straight or nearly so. ....... 6. Hormiscium.
Hyphe hyaline. ..........-----+5-0055 7. Monilochetes, p. 597.

Thielaviopsis Went. * (p. 595)

Hyphe creeping, subhyaline; conidiophores simple, septate;
conidia of two kinds; macroconidia catenulate, ovate, fuscous;

C i!
Fic. 399.—T. ethaceticus. es
After Wakker and Fic. 400.—Torula. After
Went. Saccardo.

microconidia cylindric, hyaline, catenulate within the conidiophore.
In part=Trichospheria.

Only two species, both of economic importance.

T. paradoxa (d. Seyn) v. Héhn (=Chalara paradoxa.)

Macroconidia 16-19 x 10-12 yw; microconidia 10-15 x 3.5-5 u.

It is the cause of a pineapple rot, in which rdéle it was first de-
scribed in 1886; and of a sugar cane disease.?”

In addition to micro and macrospores the fungus possesses a
pycnidial form. With variation of the substratum the spores vary

THE FUNGI WHICH CAUSE PLANT DISEASE 597

considerably from the typical. In disinfection tests Patterson and
Charles ** showed the macrospores to be considerably more resist-
ant than the microspores, also that fumigation kills superficial
spores and spores placed in incisions in the fruit.

T. podocarpi Pet. is known from Podocarpus roots.”

Torula Persoon (p. 595)

Hyphze decumbent; conidiophores short, scarcely different
from the conidia, which are catenulate, breaking away singly or in
groups, dark to black, oblong to fusoid, smooth or roughened.

Some one hundred fifty species, chiefly saprophytes.

T. exitiosa d. Seyn is said to cause much injury to chestnuts.

T. spherella Cke. causes a sooty mold of coffee.

Monilochetes Ellis & Halsted **° (p. 596)

Hyphe brown; conidiophores obsolete or very short, conidia
like; conidia in chains, moniliform, dark; some chains interspersed
with larger conidia.

Monotypic and poorly known. =

M. infuscans Ell. & Hals.**°

The mycelium grows subepidermally in sweet potato roots
causing discoloration and withering. The conidiophores arise
from the surface bearing their simple chains of conidia.

Periconieze (p. 594)

Conidia dark, capitate.

Key To GENERA oF Periconiez

Fertile hyphe simple, but often with short
apical branches
Hyphe with apical branches or conidio-
phores
Parasitic: signe ene Sees eadsula mae 1. Periconiella.
Saprophytic
Apex with heterogeneous conidio-
phores
Apex swollen; conidiophores 3to4 2. Haplobasidium.

598 THE FUNGI WHICH CAUSE PLANT DISEASE

Apex not swollen; conidiophores
many........ 3. Stachybotrys.
Apex short-branched, rarely simple
Apex short-branched or simple
Apex not swollen. ............ 4. Periconia, p. 598.
Apex swollen. ...........-.... 5. Stachybotryella.
Apex capitate-branched; branches
2 to 3-furcate and spine-

hearin sci we dese edeea wees 6. Cephalotrichum.
Hyphe without apical branches or co-
nidiophores
Conidia globose. .................005 7. Trichobotrys.
Conidia boat-shaped curved; hyphe
dark-ringed. ................00. 8. Camptoum.
Conidia fusoid, sometimes subhya-
MN 2.5 ahiatel sae ida, Auris aerewny 9. Acrotheca.

Fertile hyphe branched below the apex
Hyphe forked below apex; conidia ob-

MOD Bs issn eine Miles ad se ened ards 10. Synsporium.
Hyphe repeatedly dichotomous; conidia
globose or elliptic... .............. 11. Dicyma.

Periconia Bonordin 7°

Hyphe creeping, or obsolete; conidiophores simple, dark,
apically fertile; conidia globose, fuscous, solitary on short sterig-
mata. Fig. 401.

Some forty species chiefly saprophytes.

Trichosporiez (p. 594)
Conidia dark, borne singly on short lateral branches.

Key to Genera or Trichosporiee

Hyphe loose, typically saprophytic
Hyphe vesiculose-inflated here and there
Conidia-bearing vesicles pleurogynous. 1. Edemium.
Conidia-bearing vesicles acrogenous... 2. Cystophora.
Hyphe not vesiculose-inflated
Fertile hyphe erect

THE FUNGI WHICH CAUSE PLANT DISEASE 599

Branches circinate at apex; conidia

mesogenous, muricate. ........ 3. Acrospeira.
Branches spirally twisted; conidia
exogenous... ............00.. 4. Streptothrix, p. 599.
Hyphe simple or with straight
branches.............0..0.005 5. Virgaria.
All hyphe more or less creeping
Branches curved or lash-like. . . 6. Campsotrichum.
Branches not curved ~
Conidia spiny, rarely smooth..... 7. Zygodesmus, p. 599.
Conidia smooth
Conidia sessile................ 8. Trichosporium.

Conidia on stalks
Conidia on tooth-like sterig-

MAUR. bes csces eae sguns 9. Rhinocladium.
Conidia on jar-like stalks.... 10. Basisporium.
Hyphe forming a crust, parasitic.......... 11. Glenospora.

Streptothrix Corda

Conidiophores erect, monopodially branched,
the branches spirally coiled; conidia apical or
lateral, single, sessile or with short sterigmata,
dark colored.

A small genus. S. dassonvillei Broc-Ros. is
noted as the cause of mold of grain and fod-
der.337

Zygodesmus Corda

Hyphz and conidiophores creeping, the lat-
ter branched, light or dark colored, here and
there irregularly inflated, septate at the swel-
lings; conidia globose or ovate, muricate, rarely
smooth, on short sterigmata or on basidia-hke
branches of the sterigmata. Fic. 401.—Periconia.

: : is After Saccardo.

Some fifty species, chiefly non-parasitic.

Z. albidus E. & H.¥

Halsted describes a disease characterized by a floury coating
on violet leaves and ascribes it to this species.

600 THE FUNGI WHICH CAUSE PLANT DISEASE

Monotosporee (p. 595)

Conidia dark, solitary, acrogenous.

Key To Geners or Monotosporee

Sterile hyphe lacking
Fertile hyphe short and fascicled at
DASE: i yan Hey aea wee toe cabs ees 1. Hadrotrichum.
Fertile hyphe longer, separate........ 2. Monotospora.
Sterile hyphe present

Conidia with a loose hyaline membrane. 3. Nigrospora.
Conidia without a membrane
Conidia with a large shining drop... 4. Sporoglena.
Conidia without a shining drop. ...... 5. Acremoniella, p. 600.

Acremoniella Saccardo

Hyphe creeping, simple or ramose, hyaline or colored; conidio-
phores simple, short, subbulbous below;
conidia globose to ovoid, fuscous.

About a dozen species.

A. occulta Cav. forms brownish-yellow
flakes on the stems of cereals;

A. verrucosa Togn. on wheat in

LN Y 5 Italy.
= iN Fic .
Fig. 402.—Acremoniella. Haplographiee (p. 595)

After Bonorden.

Conidia dark, catenulate.

Key To GENERA oF Haplographier.

Sterile hyph all creeping or obsolete
Fertile hyph simple, not branched at tip

Chains of conidia lateral. .......... 1. Dematium.
Chains terminal
Conidia without isthmi........ 2. Catenularia.
Conidia connected by cylindric
MSEHM 5 os 2 wes Rode ences ahees 3. Prophytroma.
Fertile hyphe branched

Hyphe dendroid.................. 4. Hormodendrum, p. 601.

THE FUNGI WHICH CAUSE PLANT DISEASE 601

Hyphe capitate branched at tip.... 5. Haplographium.
Some sterile hyph erect and mixed with
the fertile... 0.2... cee cee ee ees 6. Hormiactella.

Hormodendrum Bonarden (p. 600)

Hyphe creeping; conidiophores erect, septate, brown, variously
dendritically branched; conidia catenulate on
the branches, globose, ovoid, olivaceous to
fuscous.
About a dozen species. G
H. hordei Bruhne on barley stems and
leaves often reduces the yield.
Spots brown, scattered over the entire leaf or
confluent, oblong; hyphz simple, septate; co- E
nea : dt Fia. 403.—H. hordei.
nidia various, cylindric, rounded or subatten- ~~ After Bruhne.
uate, or ellipsoid to subglobose, verrucose.

Dematiacee-Didymospore (p. 594)

Conidial 1-celled, dark, rarely hyaline, ovoid or oblong.

Key To GENERA OF Dematiacez-Didymospore

Hyphe very short or scarcely different from
the conidia
Conidia not in chains

Hyphe lacking..................... 1. Dicoccum, p. 602.
Hyphe present, circinate. ........... 2. Cycloconium, p. 602.
Conidia in chains....................- 3. Bispora.

Hyphez distinctly different from the conidia
Conidia smooth, muticate
Conidia not capitate
Conidia more or less catenulate at
first
Hyphe and conidia biform, the
latter 1-celled or continuous,
dark or hyaline. ............ 4. Epochnium.
Hyphe and conidia uniform
Hyphe here and there inflated 5. Cladotrichum.

602 THE FUNGI WHICH CAUSE PLANT DISEASE

Hyphe not inflated
Hyphe erect; conidia long-
catenulate. ............ 6. Diplococcium, p. 603.
Hyphz somewhat decumbent;
conidia short-catenulate
or finally solitary. ...... 7. Cladosporium, p. 606.
Conidia not catenulate
Hyphe beautifully flexuose-
torulose.. 6.6... 2... cee eee. 8. Polythrincium, p. 603.
Hyphe not torulose or flexuose
Hyphe inflated at tip, branched 9. Pseudobeltrania.
Hyphe not inflated, usually
short and little branched
Conidia merely acrogenous
Conidiophores short, 1 or 2-

septate.............. 10. Fusicladium, p. 606.
Conidiophores rather long,
multiseptate......... 11. Passalora, p. 607.
Conidia acro-pleurogenous... 12. Scolecotrichum, p. 607.
Conidia capitate.................005 13. Cordana.
Conidia muriculate or ciliate
Conidia muriculate................. 14. Trichocladium.
Conidia ciliate at apex; fertile and
sterile hyphz intermixed......... 15. Beltrania.

Dicoccum Corda (p. 601)

Hyphe creeping, chiefly very short, simple; conidia elongate
or short-clavate, dark.

About a dozen species.

D. rose Bon. produces spots on rose leaves.

Cycloconium Castaigne (p. 601)

Hyphe in the walls of the epidermis, dichotomous branched,
very fugacious, black; conidia ovoid, solitary.

There is one species:

C. oleaginum Cast. Mycelium circinate, fugacious, black;
conidia sessile, ovoid, yellow-green.

It forms blotches on olive leaves and on peduncles of the fruit
in Italy and France and is somewhat injurious in California.?*

THE FUNGI WHICH CAUSE PLANT DISEASE 603

Diplococcium Grove (p. 602)

Conidiophores erect, septate, branched, olivaceous; conidia
catenulate, 2-celled.

Fic. 405.— Clodosporium cu-
cumerinum, mycelium, a
hyphal knot, conidiophore

Fic. 404. — Cycloconium and spores. After Hum-

oleaginum. After Boyer. phrey.

D. conjunctum (Bon) Sace. is reported as a parasite of the
geranium. *®

Cladosporium Link (p. 602)

Hyphe decumbent, intricately-branched, olivaceous; conidia
globose to ovoid, greenish. In part=Mycospherella. See p. 243.

Some one hundred seventy-five species, many of them of
economic importance.

C. fasciculare Fr. on hyacinth=Pleospora hyacinthi. See p. 260.

C. herbarum (Pers.) Lk. on many hosts=Mycospherella tu-
lasnei. See p. 247.

604 THE FUNGI WHICH CAUSE PLANT DISEASE

C. herbarum (Pers.) Lk. var. citricolum.”» 2-2

Fawcett °° recognizes this as the cause of scaly bark of Citrus.
The fungus was grown in pure culture and inoculations were made
resulting in from forty to sixty days in typical spots. From these
the fungus was re-isolated.

C. cucumerinum E. & A.?” 785287

Effused, maculose; in mass greyish-brown, changing to dark
olivaceous, forming spots on fruits; condiophores cespitose,
sparingly septate, simple, denticulate, pale; conidia ovoid, lemon-
shaped or fusoid; olivaceous, 10-13 x 3-4 yp. It causes watery
spots on cucumber leaves, also decayed spots in fruit.

C. elegans Penz. is the cause of disease on various kinds of
oranges in Italy. This species is in the literature much confused
with the next.

C. citri Mas. 8% 288-291

Conidiophores tufted, erect, branched, septate, brown, 30-75
x 2-4 yp; conidia fusiform, dusky, continuous, or 1 to 3-septate,
8-9 x 2.54 p.

The cause of scab on lemons, sour oranges, satsumas and pom-
elos. It was grown in artificial culture by Fawcett.

C. carpophilum Thiim.* 292-*94 459

Spots orbicular, often confluent, blackish-green, forming circles;
conidiophores erect, simple, sinuous, septate; conidia
ovate, obtuse, continuous or 1-septate, 10-12 x
4-6 yp.

This is the cause of the widely distributed scab
of peach, plum, nectarine, apricot, cherry. The
deep olive-brown hyphe are found intermingled
with the hairs of the peach. The disease was first
pie aes noted in Austria in 1877. The fungus was cultured

carpophilum. 2nd inoculations were made by Chester.”

Alter'Cobb. In the twig the fungus breaks the cuticle from
the layers below and its hyphe project through cracks. Upon the
leaf it causes shot holes.

C. sicophilum Far. attacks fig fruits.

C. fulvum Cke.*?

Conidiophores densely crowded rupturing the cuticle, sparingly
branched, septate, nodulose, bearing a few conidia near the apex;

THE FUNGI WHICH CAUSE PLANT DISEASE 605

conidia elliptic-oblong, 1-septate, translucent, tawny, 10-20 x 4-
6 py.

The hyphez are abundant on the lower sides of tomato leaves,
forming a mold, varying from whitish to purplish in color.

It causes serious disease in Europe and America.

C. condylonema Pass. is found on leaves of Prunus causing leaf
spot and curl.

C. bigarardia is on Citrus.

C. macrocarpum Preu.”

Subeffuse, black; conidiophores subfasciculate, simple, some-

Fic. 407.—C. fulvum. After Southworth.

what flexuose, brown; conidia oblong, oblong-ovate, 2 to several
septate, obtuse, pale brown.

On spinach leaves in New Jersey, causing disease.

C. graminum Cda.

Clusters minute, irregular, scattered, greyish-brown; conidio-
phores distinct, erect, simple, nodulose-flexuose, brown; co-
nidia concolorous, continuous to several-celled, rounded or
oblong.

It is reported that this fungus was commonly present on sterile
wheat florets and that inoculation with it increased such sterility
slightly.

C. oryze S. & Sy. is on rice;

C. orchidis C. & M. on Oncidium;

C. pisi Cu. & Ma. on Pisum.

606 THE FUNGI WHICH CAUSE PLANT DISEASE

C. peoniz Pass.

Spots large, chestnut brown, hyphe short, simple; spores
various, long, 1 to 2-septate. On peony.

C. epiphyllum Mart. is on oak, sycamore, poplar, etc.;

C. juglandis Cke. on walnut;

C. scribnerianum Cav. on beech;

C. hypophyllum Fel. on elm;

C. tuberum Cke. on sweet potato tubers;

C. scabies Cke. on tomato and cucumber;

C. oxycocci Sh. on cranberry.

C. zew Pk.

Sterile hyphe hyaline, sub-cutaneous, erumpent; spores elliptic-
oblong, 4 x 20 yu, continuous or 1 to 3-septate. :

In immature corn grains.

C. brunneo-atrum McA. is on orange leaves and young shoots
in Australia;

C. javanicum Wak. on sugar cane in Java causing root molds.

Polythrincium Kunze & Schmidt (p. 602)

Conidiophores erect, fasciculate, regularly flexuose or toru-
lose, black, simple; conidia acrogenous, obo-
void.

Monotypic. Inpart=Phyllachara. See
p. 220.

P. trifolii Kze. on clover=Phyllachora tri-
folii. See p. 220.

Fusicladium Bonardin (p. 602)

Conidiophores short, erect, straight, spar-
Fic. 408.—P. trifolii. ingly septate, subfasciculate, olivaceous; co-
Biter Ponds, nidia ovoid or subclavate, continuous or

l-septate, acrogenous, solitary or paired.

In part=Venturia and Phyllachora.””” 7

Over forty species, several pathogenic.

F. fraxini Aderh. on Ash.=V. fraxini. See p. 255.

F. saliciperdum (All. & Pub.) Land. on Salix=V. chlorospora.
See p. 255.

F. cerasi (Rab.) Sacc. on cherry, peach,=V. cerasi. See p. 255.

THE FUNGI WHICH CAUSE PLANT DISEASE 607

F. pirinum (Lib.) Fel. on pear=V. pirinia. See p. 253.

F. dendriticum (Wal.) Fel. on pomaceous fruits=V. inaequalis.
See p. 253.

F. orbiculatum Thiim on Sorbus=V. inzqualis var. cinerascens.
See p. 255.

F. depressum (B. & Br.) Sacc. on Umbbelliferee=Phyllachora.

F. betule Aderh. on birch=V. ditricha. See p. 255.

F. tremule Fr. on aspen=V. tremule. See p. 255.

F. fagopyri Oud. is found on buckwheat;

F. lini Sor. on Linum.

F. eriobotryz Cav. attacks leaves of Eriobotrys.™”

F. destruens Pk.

Conidiophores short, 20-50 u, fasciculate, continuous or 1
to 2-septate, basally, colored, clusters slightly olive-green; conidia
acrogenous, continuous or 1-septate, subcatenulate, ellipsoid
to oblong, colored, 7-20 x 5-7 ys.

On oats.

F. effusum Wint.2%

Spots minute, rounded, rarely effused, confluent, smoky; coni-
diophores erect, simple or slightly branched, septate, torulose,
brownish, lighter above, 100-140 x 4 u; conidia oblong fusoid to
rhomboid, continuous or uniseptate, light fuscous, subtruncate,
17-24 x 5.5-7 yp.

It constitutes the pecan scab affecting the leaves, stems and nuts.

F. vanillz Zim. is on vanilla.

An undetermined species is the cause of a black canker of Hevea.

Passalora Fries & Montaigne (p. 602)

Conidiophores filiform, intricate multiseptate, olive; conidia
oblong to fusoid, acrogenous.

A small genus quite similar to Fusicladium except for the pluri-
septate conidiophores.

P. bacilligera M. & F. and P. microsperma Fcl. occur on Alnus.

Scolecotrichum Kunze & Schmidt (p. 602)

Conidiophores short, subfasciculate, olive; conidia oblong or
ovate, pleurogenous or acrogenous.
A genus of some thirty species very similar to Fusicladium.

608 THE FUNGI WHICH CAUSE PLANT DISEASE

S. graminis Fcl.

Spots foliicolous, elongate, ochraceous; conidiophores densely
‘ fasciculate, filiform, simple, sinuose, 90-100 x
6-8 py, subcontinuous; conidia fusoid-ohbclavate,
35-45 x 8-10 y, uniseptate, olive-brown.

It is common, causing leaf spots on grasses,
especially on Avena and Phleum. It is de-
scribed on the latter by Trelease.“* The my-
celium collects below the stomata and pushes
j its tuft of hyphe through them.
= S. melophthorum P. & D. parasitizes melons
enn _ and cucumbers in France;

Fig, 409.8. erami- _§. fraxini Pass. is on ash.

cardo. S. iridis F. & R. is on Iris;

S. musz on banana.

S. avene Erik. is on oats.

Dematiaceze-Phragmospore (p. 594)

Conidia 2 to many-celled, dark, rarely light or hyaline, ovoid to
cylindric or vermicular.

Key to Genrera or Dematiacee-Phragmospore

Fertile hyphz very short or little different
from the conidia
Conidia not in chains
Conidia muticate
Conidia united at base, fasciculate,
cylindric. ................. ... 1. Cryptocoryneum.
Conidia separate
Conidia straight ovoid to cylindric

Conidia solitary.............. 2. Clasterosporium, p. 609.
Conidia in bundles........... 3. Stigmina, p. 610.
Conidia fusoid-faleate. .......... 4. Fusariella.

Conidia cuspidate or setose
Hyphe dichotomous and broadened

BtOPEXS site deve Bade ee 5. Urosporium.
Hyphe not dichotomous or broad-
OHO: sway gone th Sees chee ae 6. Ceratophorun, p. 610.

Conidia in chains

THE FUNGI WHICH CAUSE PLANT DISEASE

Conidia not connected by isthmi

609

7. Septonema.

Conidia connected by isthmi. ........ 8. Polydesmus.

Fertile hyphe distinctly different from
the conidia
Conidia solitary or nearly so, acrog-
enous for the most part
Conidia muticate. ..............
Conidia echinulate
Conidia smooth
Hyphe creeping, radiate. ....
Hyphe short, ascending or
erect, conidia ovoid to
oblong................
Hyphe longer, rigid; conidia
ovoid to elongate
Conidia ovoid............
Conidia elongate..........
Hyphz flexuous, pannose....
Conidia 1 to 3-ciliate at apex.....
Conidia verticillate or capitate
Hyphe dark
Conidia acrogenous, forming a
head
Hyphz simple. .............
Hyphz branched at the apex.
Conidia pleurogenous, some-
what verticillate
Hyphe rostrate and naked at
APEXi acceded kis tenhae
Hyphe not rostrate at apex. .
Hyphe hyaline or bright colored,
apex denticulate............
Conidia catenulate as a rule
Conidia arising from the interior of
the hyphe.. ..............
Conidia arising from the apex,
sometimes solitary. .........

11.

12.

21.

Iv.

V.

. Helminthospora.
. Heterosporium, p. 610.

Ophiotrichum.

Napicladiun, p. 611.

. Brachysporium.

. Helminthosporium, p. 611.
. Drepanospora.

. Camposporium.

. Acrothecium.
. Atractina.

. Rhynchomyces.
. Spondylocladium, p. 614.

Neomichelia.

Sporoschismez.

Dendryphiee, p. 615.

Clasterosporium Schweinitz (p. 608)

Hyphz creeping, here and there swollen, erect, bearing 2 to
several-septate, solitary, apical conidia.

610 THE FUNGI WHICH, CAUSE PLANT DISEASE

A genus of some seventy-five species.

C. glomerulosum Sacc. on Juniperus leaves is often reported
as Sporodesmium glomerulosum.

C. carpophilum (Lév.) Aderh.*® °° 9 47? Aderhold by inocu-
lations, properly controlled, showed this fungus capable of causing
gummosis of prunaceous hosts though C. herbarium did not do so.

Iiffuse, hyphe simple or short-branched, densely aggregated,
septate, conidia elongate-fusoid, obtuse, 4 to 5-septate, slightly con-
stricted at the septa. It is commonly seen as
f the cause of a brown spot on peaches. Spores
do not appear in the young spots but are found
sparingly in older brown areas.

Pures culture inoculations by Stewart * on
peach twigs resulted in blackening and gum-
Fig. 410.—Stigmina. mosis.

Alter Baonardo, C. amygdalearum (Pass.) Sacc. is also de-
scribed on rosaceous hosts. It is perhaps identical with C. car-
pophilum and may be connected with Pleospora vulgaris.27!

C. putrefaciens (Fcl.) Sacc. causes spots on leaves of the sugar-
beet.

Stigmina Saccardo (p. 608)

Hyphe epiphyllous; conidiophores very short or obsolete; coni-
dia ovate or elongate, 3 or more-celled, aggregated.
S. briosiana Far. causes disease of apricots in Europe.

Ceratophorum Saccardo (p. 608)

Hyphe creeping, scant; conidiophores short, erect; conidia
fusoid or cylindric, 2 to many-septate, dark or reddish-brown.

A small genus.

C. setosum Kirch. is found on leaves and shoots of young plants
of Cytisus, etc., in greenhouses;

C. ulmicolum E. & K. on Ulmus leaves.

Heterosporium Klotzsch (p. 609)

Hyphe subcespitose, smoothish, often branched; conidia oblong,
2 to several-septate, smoothish to granular or echinulate.
A genus of forty species or more.

THE FUNGI WHICH CAUSE PLANT DISEASE 611

H. echinulatum (Berk.) Cke.21 34

Spots gregarious, on fuscous areas; conidiophores fasciculate
from a stromatic base, 150-200 x 8 u, rarely shorter, flexuose-
nodose, fuliginous; conidia at the nodes, oblong-cylindric, rounded
at the ends, 2 to 3-septate, 40-50 x 15-16 y, slightly constricted,
roughened, brownish.

It causes a destructive mold on carnation leaves and stems. The
first epidemic was noted by Sorauer in Berlin in 1883.

H. gracile (Wal.) Sacc. was determined to be the cause of dis-
ease of Iris, Narcissus and other Monocotyledons.*®

H. variable Cke.**

Conidiophores flexuose, slender, more or less nodulose at the
septa; conidia cylindric oblong, 2 to 4-septate, minutely warted,
20-25 x 7-10 y, pale olive. On spinach.

Other parasitic species are:

H. ornithogali Klotz. on Liliacex;

H. laricis C. & M. on larch leaves;

H. auriculi Mas. on cultivated Auricula;

H. syringe Oud. on lilac leaves.”

H. minutulum C. & M. causes disease of hops.

Napicladium von Thiimen (p. 609)

Conidiophores short, subfasciculate, smoothish; conidia acroge-
nous, solitary, large, oblong, 2 to many-septate, smoothish.

A small genus.

N. janseanum Rac. is on rice.

N. soraueri is a form of Venturia inequalis with somewhat
atypical napiform spores. See p. 253.

Helminthosporium Link (p. 609)

Conidiophores erect, rigid, subsimple, fuscous; conidia fusoid |
to elongate-clavate or cylindric, pluriseptate, fuscous, smooth.

In part=Pleospora. See p. 259.

About two hundred species; several are important pathogens,
others saprophytes.

The species show biologic differentiation into races similar to

612 THE FUNGI WHICH CAUSE PLANT DISEASE

that exhibited in the Erysiphacee, though morphologically they
may be inseparable.

Fic. 411.—Helminthosporium gramineum. Conidio-
phores and spores. After King.

H. gramineum (Rab.) Erik. on grasses=Peleospora gramineum.
See p. 261.
H. trichostoma=Pleospora trichostoma. See p. 260.

Fic. 412.—Helminthosporium teres. Conidiophores
and spores. After King.

H. teres Sacc.
Spots oblong, olive, amphigenous; conidiophores fasciculate,
often crooked and nodulose, septate, brown, 100-130 x 12 un;

THE FUNGI WHICH CAUSE PLANT DISEASE 613

conidia acrogenous, straight, cylindrical, ends rounded, 4 to 5-
septate, not constricted, dark olive-brown, 100-115 x 14-
18 ». On oats and barley.

H. avene Ei.

Similar to H. teres, but the conidiophores scattered, 150-200 x
9-12 y, septate, brown; conidia cylindric, brownish, 4 to 6-septate,
80-100 x 15-16 pw. On oats.

The conidia of the two last species infect grains and seedlings.
The conidia spread the disease from the early infection centers
to other parts of the plants but the mycelium remains local.

H. bromi Died. on Bromus=Pleospora bromi, see p. 261.

H. tritici-repentis Died.=Pleospora tritici-repentis, see p. 262.

H. sativum (P.) K. & B.”

Mycelium branched, septate; conidiophores fasciculate, fuscous,
brown, septate, 8-10 u wide, sometimes swollen between the
septa; conidia solitary, apical, dark brown, 6 to 11-septate, 105-
130 x 15-20 p.

The cause of a destructive late blight of barley from Iowa to
Saskatchewan. The disease manifests itself by dark colored,
elongate spots on the leaves.
It also occurs on the glumes
and spikelets, sometimes even
penetrating the grains.

H. sorokinianum Sacc. is re-
ported on wheat and rye in
Russia;

H. tritici Hen. on wheat in
Africa; H. sigmoideum Cav.
on rice in Italy; while several ;
species are recorded on bam- Fis. it Biden es torte hotae:
boo. After King.

H. turcinum Pass.

Spots, large, dry, brownish; conidiophores, gregarious to fascicu-
late, septate, 150-180 x 6-9 u, pale olive, apex ‘almost hyaline,
often nodulose; conidia spindle-shaped, acute, 5 to 8-septate,
pale olive, 80-140 x 20-26 u.

It produces spots on corn and sorghum in Europe and America.

H. inconspicuum C. & E.5% 38-310

614 THE FUNGI WHICH CAUSE PLANT DISEASE

Conidiophores elongate, septate, nodose, pale brown; conidia
lanceolate, 3 to 5-septate, 80-120 x 20 u, smooth.

It has been reported on sweet corn from Long Island by Stewart.
H. gramineum, H. turcinum and H. incon-

spicuum are closely related, possibly identical.
Johnson *° concludes that H. gramineum with
its ascosporic stage includes Piricularia grizea,
P. oryze, Helminthsporium oryz# and H. tur-

» cinum.

H. inzequalis Sh.
a Sterile hyphz effuse, much branched, dark
a brown; conidiophores erect, septate, variable

_ in length, 6-8 » in diameter; conidia both ter-

Bo Peers Piaaga minal and lateral, more or less curved, 3 to

mqualis. After 5-celled, thick-walled, brown, 23-32 x 11-14 pn.

hear.
On cranberry.

H. hevez Petch. is on Para rubber;

H. thee Bernard on tea in India;

H. iberidis Poll. on Iberis and H. lunariz Poll. on Lunaria, both

in Italy.
Spondylocladium Martius (p. 609)

Hyphez creeping, septate; conidiophores erect, simple, rigid;
conidia v2rticillate, fusoid, usually 3-celled, brownish.

A smali genus.

S. atrovirens Harz.™

Conidiophores solitary or clustered, cylindric, septate, dingy,
olive or brownish, up to 400 » high; conidia elongate, ovate, apex
narrowed, 5 to 7-septate, concolorous with the conid-
iophores, 30-50 x 6-9 uz.

On potatoes this fungus causes blackish to olive
spots soon depressed, 2-3 cm. across, which are
beset with small black sclerotia and followed by dry
rot. According to Appel & Laubert 31! the sclerotia
develop whorls of conidiophores. The species is Ms ue
said to occur in the British Isles, the Continent After Masse.

and in America.*!? Its sterile mycelium has been described under
the name Phellomyces.?%

THE FUNGI WHICH CAUSE PLANT DISEASE 615

Dendryphium Wallroth (p. 609)

Hyphe creeping or obsolete; conidiophores erect, with short
apical branches; conidia cylindric, 2 to many-septate, catenulate,
brown.

Some thirty or more speciés.

D. comosum Wal. is the cause of a cucumber leaf spot in England.

Dematiacez-Dictyospore (p. 594)
Conidia dark, rarely light, muriform, globose to oblong.

Key To Genrra oF Dematiacee-Dictyospore.

Hyphe very short or scarcely different from
the conidia............. 0. cece eee eee I. Micronemee.
Conidia not in chains
Conidia not appendaged
Conidia irregularly muriform or
sarciniform
Conidia with a conic point at each
SIME e ears ranean: 1. Oncopodium.
Conidia without conic points
Conidia globose to oblong
Conidia ovoid to oblong, loose 2. Sporodesmium, p. 616.
Conidia globose to ovoid, ag-

gregated............... 3. Stigmella.
Conidia sarcineform, often co-
alescent. ............006 4. Coniothecium, p. 617.

Conidia as if camposed of parallel
chains of cells
Chains of conidia never separat-

ANG iace areierspateg gatetchnan seas 5. Dictyosporium.
Chains of conidia separating. . ... 6. Speira.
Conidia corniculate at apex. ......... 7. Tetraploa.
Conidia in chains, often asperate or with
ISHAM es wears sie Se ies aes aeacsaie ars 8. Sirodesmium.

Hyphe distinctly different from the conidia II. Macronemee.
Conidia of the same form
Conidia not in chains or capitate
Conidia bearing little conidia on their
BUMACEB iow ie eeside bea wee ee 9. Xenosporium.

616 THE FUNGI WHICH CAUSE PLANT DISEASE

Conidia single
Hyphe alike
Conidia cruciate-divided, verru-
COSO 2225 Hed eeese ais: 10. Tetracoccosporium.
Conidia muriform, typically
smooth
Hyphe decumbent.......... 11. Stemphylium, p. 617.
Hyphe erect or ascending
Conidia globose, pleuro-
_ gynous
Conidia around the apex
of the hyphe......... 12. Coccosporium.
Conidia conglobate
around the base...... 13. Trichegum.
Conidia ovoid to oblong,
mostly acrogenous
Conidiophores somewhat

lax, colored. ....... 14. Macrosporium, p. 618.
Conidiophores rigid, very
darks: iiivns evacuees ¢ 15. Mystrosporium, p. 620.
Hyphe of two kinds, longer
sterile, shorter fertile......... 16. Septosporium, p. 620.
Conidia capitate. ................0.. 17. Dactylosporium.

Conidia catenulate
Hyphz velvety, erect, subsimple;
conidia caudate............... 18. Alternaria, p. 621.
Hyphz crustose, various; conidia 2-
celled; conidia-like ganglia sar-

Cineform sc6 ives serie esenc ees 19. Fumago, p. 624.
Conidia of two forms, dark sarcineform
and subhyaline falcate............. 20. Sarcinella, p. 625.

Sporodesmium Link.*" (p. 615)

Mycelium and conidiophores poorly developed; conidia ovoid
oblong, subsessile or short-stalked, rather large, clathrate-septate,
fuligineus.

Over eighty species.

S. piriforme Cda. on oranges=Pleospora hesperidearum,
p. 260.

S. exitiosum Kiihn on crucifers=Leptospheria napi, p. 258.

THE FUNGI WHICH CAUSE PLANT DISEASE 617

S. exitiosum var. solani Schenck is reported as the cause of a
potato disease.

S. solani-varians Vanha is the cause of
potato disease in Europe, the foliage bearing
brown spots and finally dying in a manner
resembling death caused by Phytophthora.
Cladosporium and pycnidial forms are said
to exist.

S. mucosum Sacc. was reported by Ader-
holt on cucumber fruit and leaves causing
disease.

S. scorzonere Aderh. causes a salsify
stem and leaf disease.*!4

Other parasitic species are:

S. melongena Thiim. on egg plant;

S. dolichopus Pass. on potato leaves in a
Italy; Fia. 416.—Sporodesmium

antiquum. After Sac-
S. ignobile Karst. on asparagus; cardo.

S. putrefaciens Fcl. on beet;
S. brassicze Mas. on Brassica in Bengal.

Coniothecium Corda (p. 615)

Hyphez obsolete or poorly developed; conidia
gemmiform in origin, variously septate.

Over fifty species of very simple parasitic or
saprophytic fungi.

C. chomatosporum Cda. resembling apple
scab in its effect is noted as common in Tas-
mania! and Australia.‘

Stemphylium Walroth (p. 616)

Conidiophores decumbent, intricately
branched, hyaline or smoky; conidia acrogenous,
eS ovoid to subglobose, 2 to many-muriform-
sa ag septate, fuligineus.
cardo. Over thirty species.
S. ericoctonum B. & deB. is parasitic on Erica in green-houses.

618 THE FUNGI WHICH CAUSE PLANT DISEASE

S. citri Pa. & Ch.”

Vegetative mycelium long, hyaline, becoming dark, 4 » in
diameter, septate; conidiophores short; conidia dark brown, sub-
globose to oblong, apiculate, irregularly muriform, 20-30 x 12-
15 u, usually in chains of three.

This was found associated with an end-rot of oranges from
Arizona. Inoculated in pure culture in oranges the fungus de-
veloped well. It is perhaps the cause of the disease.

S. tritici Pa.

Hyphe irregularly branched; conidiophores closely septate,
4-5 » in diameter; conidia catenulate, irregular, usually clavate,
constricted slightly at the septa, 24-35 x 12-15 yu, vermiculate,
fuligineus, isthmus short, 3-4 uw in diameter. It is described as
the cause of floret sterility of wheat.?°> 2% 91% 435

Macrosporium Fries (p. 616)

Conidiophores fasciculate, erect or not, more or less branched:
colored; conidia usually apical, elongate or globose, dark-colored.

In part=Pleospora. See p. 259.

About one hundred: eighty species, many of them saprophytes
while others are important pathogens.

M. commune Rab.=M. sarcinula parasiticum Thiim. on vari-
ous grasses=Pleospora herbarium. *!” 318 See p. 260.

This is reported by Thaxter °"” as the common black mold which
follows Peronospora on the onion and which occurs often also on
onions not so diseased, being especially common on the seed stalks.
It is usually associated with injured plants and may be important
only as a wound parasite.

M. porri E.*"”

Effuse, fuligineus; hyphe short, simple, subfasciculate; conidia
elongate-clavate, basally attenuate, multiseptate, 150-180 x
12-20 pu.

It is common on seed onions, less common on market onions.
The dark mycelium penetrates the host in all directions and finally
produces stromata below the stomata and sends up short hyphe.

M. alliorum C. & M. is also on onion; 8

M. hurculeum E. & M.

Amphigenous on rounded, grey spots; conidiophores erect, ces-

THE FUNGI WHICH CAUSE PLANT DISEASE 619

pitose, flexuose, brown, few septate, 70-80 x 5 u; conidia brown,
multiseptate, clavate, 200-225 x 21-26 uy.

It causes leaf spots on turnips, horse radish and other crucifers.

M. brassice Berk.

Mycelium inconspicuous, conidia clavate, antenneform, 5 to
11-septate, 50-60 x 12-14 u.

It is a common cause of black mold on cabbage, collards and
other crucifers.

M. ramulosum Sacc. is on celery.

M. catalpe E. & M. *4

On brownish spots; conidiophores brown, curved, nodose, 8 to
12-septate, erect, amphigenous, 90-135 x 6 yu; conidia brown,
obovate to pyriform, submuriform, 27-54 x 15-27 yu.

Producing leaf spots on Catalpa in company with Phyllosticta
catalpe.

M. nobile Vize. is on Dianthus.

M. iridis C. and E. and M. aductum Mas. are on iris;

M. cheiranthi (Lib.) Fr. on Cheiranthus.

M. tabacinum E. & E.*" causes thin, white amphigenous spots,
2-3 mm. with a narrow dark border; conidiophores effused, 35-45 x
3-4 yp, septate and torulose above; conidia obovate, 15-25 x 10-
12 wu, sessile or short stipitate, usually 3-septate.

It is reported to cause white leaf spots on tobacco.

M. longipes E. & E.

On concentric, rusty brown, amphigenous spots, 3 to 5 mm. in
diameter; conidiophores effused, amphigenous, slender, 40-70 x
3-4 yw, septate, often contracted at the septa, erect and more or
less torulose above; conidia clavate, 40-50 x 15-20 yu, 3 to
7-septate, attenuate below into a distinct stipe. On tobacco.

M. sarciniforme Cav. is reported by Walkoff #24 on red clover
in Germany where it causes the leaves to dry and die.

M. nigricanthium Atk.”

Amphigenous; condiophores subfasciculate or scattered nodose,
septate, olive-brown, 50-140 x 6-7 u; conidia olive-brown, con-
stricted about the middle, rostrate at one side of the apex, 18-
22 x 36-50 uw. On cotton.

M. cucumerinum FE. & E.3?3:324

Epiphyllous on orbicular, subconfluent, brownish spots, 3-4

620 THE FUNGI WHICH CAUSE PLANT DISEASE

mm. in diameter; conidiophores fasciculate or
solitary, subgeniculate, 1 to 3-septate, 35-50 x
5-6 pw; conidia clavate, slender-stipitate, 3 to
8-septate, somewhat constricted, submuriform,
30-75 x 15-25 yu; pedicel 25-35 yu long.

On leaves, stems and fruits of cantaloupes.

M. cladosporioides Desm. is on beet, lettuce,
onion and many other hosts.

M. verrucosum Lutz. occurs on cacao;
M. gramineum Cke.** on sugar cane.
M. uvarum Thiim. is reported on Vitis;
é e M. viole Poll. on violets in Italy;
Se ene M. saponarize Pk. on Saponaria,
un oe pepe M. macalpinianum 8. &. Sy. is injurious to
Chester. Pelargonium.

Mystrosporium Corda (p. 616)

Conidiophores simple or sparingly branched, short, septate,
‘fuscous, rigid; conidia elliptic, subglobose or oblong, pluriseptate,
muriform, dark, usually solitary, acrogenous.

Some twenty species.

M. abrodens Nebr. is described as the cause of a very serious
grain disease in France.

M. aductum Mas. injures Iris bulbs;

M. alliorum Berk. forms dark spots on onion.

Septosporium Cda. (p. 616)

Conidiophores short, intermixed with longer sterile hyphe;
conidia ovoid to pyriform, fuscous.

A small genus.

S. heterosporium E. & G.

Spots scattered, confluent or not, rusty brown, 0.5-1 cm. in
diameter, conidiophores hypophyllous, fasciculate from the sto-
mata; conidia variable, oblong cylindric, constricted at the
septa, 20-40 x 5-7 u, separating into gemma.

Reported in 1888 * on the wild grape in California.

THE FUNGI WHICH CAUSE PLANT DISEASE 621

Alternaria Nees. (p. 616)

Conidiophores fasciculate, erect, sub-simple, short; conidia
clavate-lageniform, septate, muriform, catenulate.

In part=Pleospora. See p. 259.

Some thirty or more species, many of pronounced economic im-
portance.

A. sp. on Tropceolum=Pleospora tropceoli. See p. 260.

A. trichostoma Died. on barley=Pleospora trichostoma. See
p. 260.

A. forsythie Harter.

Hyphe cespitose, amphigenous; spot concentric zonate: conidia
18-60 x 10 x 16.5 yp.

It causes subcircular leaf spots on cultivated Forsythia.

A. brassice (Berk.) Sacc.

Conidiophores short, continuous, short-branched, apically
equal, conidia elongate, fusoid, clavate, 60-80 x 14-18 yu, 6 to 8-
muriform-septate, olivaceous.
On crucifers.

A. brassicae (Berk.) Sacc.
var. phaseoli Brun. occurs on
beans in Italy.

A. cucurbite Let.!2 37 may
be identical with A. brassice.

It was noted by Thax-
ter in Connecticut causing
blight of melons. The black Fis. Aig: =A: Viole corminseing spores.
mold is copious in the older
circular spots. Pure cultures were obtained and successful in-
oculations were made on normal uninjured melon leaves.

It is also reported by Selby!” as the probable cause of muskmelon
leaf spots in Ohio, and it is a common source of troubles on various
cruciferous hosts.

A. tenuis Nees.** is reported by Behrens on tobacco seedlings.

A. viole G. & D.

Conidiophores erect, pale-olive, septate, simple, 25-30 x 4 uy,
conidia in chains at or near the apex of the conidiophore, clavately

622 THE FUNGI WHICH CAUSE PLANT DISEASE

flask-shaped, strongly constricted at the septa, olive, 40-60 x
10-17 p.

Circular leaf-spots are produced on violets. Spores are found on
the spots only when conditions are most favorable, i. e., in a humid
air. The parasitism of the fungus was demonstrated by inocula-
tion with spores on living leaves in distilled water.

A. panax Whet.?*

Spots amphigenous, circular, becoming dingy white with a

Fic. 421.—A. dianthi. 3, Mycelium showing
branching and septation. 4, Showing my-
celium below stoma and hyphe emerging

Fic. 420.—Alter- through the stoma. 6, Showing catenu-
naria. Spores late spores as borne upon hyphz._ 6, Spores
and spore-bear- showing shape, septation and catenulation.
ing stalks. Af- 7, A young cluster of hyphe. 8, An older
ter van Hook. cluster of hyphe. After Stevens and Hall.

reddish-brown margin, covering half the leaflet or less; hyphe
brown, septate, 5-7 » in diameter; conidiophores erect, tufted,
somewhat irregular, especially at the tips, brown, septate, 100-
120 x 5-6 yw; conidia brown, in chains of 5 or 6, elliptic to oblong,
45-65 x 15-20 py. :

On ginseng causing leaf blight.

A. dianthi §. & H.3

Spots epiphyllous, ashen-white, definite, circular. Conidiophores
cespitose from stomata, amphigenous, dark-brown, 1 to 4-septate,
erect, 1-25 from a stoma; conidia 26-123 x 10-20 u, clavate,

THE FUNGI WHICH CAUSE PLANT DISEASE 623

tapering, obtuse, basally dark-brown, slightly constricted at the
septa, 5 to 9 times cross-septate and 0-5 times longitudinally
septate.

It causes injury on carnation leaves and stems.

A. solani (E. & M.) Jones & Grout. 5% 99% 933-387

Spots brown, circular to elliptic, concentrically zonate, amphige-
nous, irregularly scattered over the leaf surface; mycelium

Tr

Fie. 422.—A. solani, 2, spores germinating and penetrating the living
potato leaf; 5, showing catenulation of spores. After Jones.

light-brown; conidiophores erect, septate, 50-90 x 8-9 yu; conidia
obclavate, brown, 145-370 x 16-18 » with 5 to 10 transverse
septa, longitudinal septa few, conidia terminating in a very long
hyaline, septate beak 14 the length of the conidium or longer.

It causes early blight, a leaf spot disease of potatoes and toma-
toes,*3? and is widely prevalent. It was first described in 1882 in
America but is now known to be widely destructive.*** Qn potatoes
it was first recorded by Galloway in 1891. In 1891 also Ches-
ter 45° and Galloway ** proved its pathogenicity by inoculations on

624 THE FUNGI WHICH CAUSE PLANT DISEASE

tomato and potato, the spots appeared in eight or ten days after
inoculation. Jones, using pure cultures, confirmed the conclu-
sions of Chester and Galloway, the disease spots appearing as early
as the third to fifth day after inoculation on vigorous uninjured
leaves. The mycelium grows luxuriantly within the leaf but spores
do not usually form until after the death of the supporting tissues
when the conidiophores emerge through the stomata or by ruptur-
ing the epidermis. Often no spores are formed and rarely are
many present. The mycelium may live a year or more and resume
sporulation the following season.

A. fasciculata (C. & E.) Jones & Grout.1% 338 33% 341

Conidiophores light or dark-brown, becoming almost black,
darker than the vegetative hyphe but like them echinulate,
30-40 x 4-5 yu; conidia concolorous with the conidiophores, 35-66
x 16-20 yp, obclavate, 3 to 6 times cross-septate, 1 to 2 longi-
tudinai septa, apical cell hyaline.

This fungus is associated as a saprophyte with the blossom-
end-rot of tomatoes and also causes a serious decay of the ripened
fruit. The literature of the disease is rather voluminous and con-
tains a number of synonyms, among them Macrosporium tomato.
M. lycopersici, M. rugosa, M. fasciculata. Alternaria solani has
also been credited with this disease and indeed the two species
may be identical.3”

A. fici Far. is on figs;

A. tabacinum Hori on tobacco; :

A. vitis Cav. on Vitis.

An undetermined Alternaria accompanied by a Macrosporium
was constantly found in Nevadillo blanco olives which were
shrivelled, particularly at the apex.

These fungi were regarded as the cause of the disease.*42

Fumago Persoon (p. 616)

Hyphe decumbent, intricate, frequently pseudo-stromatic,
black; conidiophores, erect, branched; conidia ovoid, oblong or
sarcineform, 1 to 2-septate.

A small genus, chiefly conidial forms of Capnodium and Meliola.
See pp. 192, 193.

THE FUNGI WHICH CAUSE PLANT DISEASE 625

F. camellize Cat. on various hosts=Meliola camellix. See
p. 193.

Sarcinella Saccardo (p. 616)

Hyphx decumbent, septate, branched, dark; conidiophores
much reduced; conidia of two kinds: 1, dark packet-like; 2, sub-
hyaline falcate. Both are intermixed.

A small genus chiefly conidial forms of Dimerosporium. See
p. 190.

S. heterospora Sacc. on various hosts=Dimerosporium pul-
chrum. See p. 191.

Dematiacez-Scolecospore (p. 594)

Conidia dark or subhyaline, vermiform or filamentose, multi-
septate.
There is only one genus.

Cercospora Fries

Conidiophores variable, almost obsolete or well developed,
simple or branched; conidia vermiform or filiform, straight or
curved, multiseptate, subhyaline to dark.

In part =Mycospherella. See p. 243.

The genus is a very large one, some seven hundred species, and
contains very many aggressive, important parasites, chiefly causing
leaf spotting. The spots are often blanched and are rendered
ashen colored in the centers by the presence of the dark hyphe.
The hyphe are usually geniculate at the point of spore produc-
tion, Fig. 427, and thus old hyphz bear traces of spores previously
borne.

C. cerasella Sace. on cherries =Mycospherella cerasella. See
p. 245.

C. gossypina Cke. on cotton =Mycospherella gossypina. See
p. 248.

C. circumscissa Sacc.

Spots amphigenous, circular, pallid, dry, deciduous; conidio-
phores fasciculate, nodulose, brownish, simple; conidia acicular,
narrowed apically, attenuate, tinged brown, 50 x 3.5-4 u.

626 THE FUNGI WHICH CAUSE PLANT DISEASE

On various species of Prunus this causes leaf holes.

It is reported as especially serious on the almond.***

C. bolleana (Thiim.) Sacc.

Hypophyllous, spots subfuscous to olivaceous; conidiophores
fasciculate, filiform, 50-80 x 5-6 yu, non-septate, fuscous; conidia
terete, fusoid, 35-40 x 7-8 yu, apically obtuse, somewhat con-
stricted, 1 to 5-septate, olive-green.

On figs causing leaf spotting.**4

C. viticola (Ces.) Sace.

Spots amphigenous, subcircular to irregular, 2-10 mm. in
diameter, ochraceous, emarginate; conidiophores erect, densely
fasciculate, filiform, septate, 50-200 x 4-5 yp,
straight, somewhat denticulate, ochraceous;
conidia elongate-obclavate, somewhat at-
tenuate, 3 to 4-septate, 50-70 x 7-8 uy, olive-
brown.

It is apparently an unimportant parasite
on grape leaves.

C. rubi Sacc. is on Rubus;

C. fumosa Pass. on leaves of Citrus fruits.

C. moricola Cke. is common on mulberry;

C. muse Zimm. on banana leaves in
Java.

C. reesleri Sacc. occurs in Europe, causing

6. Hyphe emerging late injury to the grape.

through astomaced C. angulata Wint."

raat and Spots roundish, angulate, whitish to cine-

y. : hea
reous, margined, 1-3 mm. in diameter, often
confluent; conidiophores hypophyllous, fasciculate, erect, straight
or only slightly flexuose, simple, brownish, few septate, 78-105 x
5 #; conidia filiform-obclavate, long attenuate, hyaline, 7 to 16-
septate, 80-170 x 3.5 uy.

On the currant.

C. oryze Miy." is on rice in Japan.

C. concors (Casp.) Sacc,1% 345

Spots amphigenous, pale above, whitish beneath, rounded, in-
definite; conidiophores fasciculate or single from the stomata,
erect, brown, septate, simple, 40-80 yu high; conidia single,

THE FUNGI WHICH CAUSE PLANT DISEASE 627

apically variable in form, ovate to elongate, curved, 1 to 5-septate,
subhyaline, 15-90 x 4-6 yu.

In America this potato parasite was noted in Vermont in 1905
and study of herbarium material revealed two earlier collections.
In Germany it was known in 1854 and it has been seen in many
parts of Europe since, sometimes in epidemic form.*4”

Conidia are abundant on the spots on stalks emerging from
the stomata. The superior and inferior hyphe differ considerably
in length and branching. Brown bead-like chlamydospores form
within the leaf. The mycelium is strictly intercellular. The fungus

Fia. 424.—C. nicoti- Fig. 425.—C. nicotianz, spores germinating and
ang. After Jones. entering stomata. After Jones.

was studied in artificial culture by Jones & Pomeroy and inocu-
lations were made, diseased spots appearing about three weeks
after inoculation by spraying with suspensions of spores.

C. nicotiane E. & E.

Spots amphigenous, pale, becoming white, with a narrow and in-
conspicuous reddish border, 2-5 mm. in diameter, conidiophores
amphigenous, tufted, brown, septate, 2 or 3-times geniculate above,
simple or sparingly branched, septate, 75-100 x 4-5 yu; conidia
slender, slightly curved, multiseptate, 40-75 x 3-3.5 yu, hya-
line.

On tobacco it causes leaf spots.*“* The sporiferous hyphe are
abundant near the center of the disease spots.

C. raciborskii 8. & Sy. on tobacco in Java and Australia,*” is a
near relative of C. nicotiane.

628 THE FUNGI WHICH CAUSE PLANT DISEASE

C. apii Fr.

Spots amphigenous, subcircular, pale-brown, 4-6 mm. in diame-
ter, with a more or less definite elevated margin; conidiophores hy-
pophylous, light-brown, fasciculate, con-
tinuous or 1 or 2-septate, subundulate,
40-60 x 4-5 y; conidia hyaline obclavate,
or almost cylindric, 3 to 10-septate, slen-
der, 50-80 x 4 un.

A serious leaf spot is produced on celery,
parsnips, etc.°°°351

C. beticola Sacc.' 352

Spots amphigenous, brownish, purple-
bordered, becoming ashy centered; co-
nidiophores fasciculate, short, simple, erect,
flavous, 35-55 x 4-5 yw; conidia elongate,
filiform obclavate, hyaline, multiseptate,
75-200 x 3.5-4 yp.

This fungus, described in 1873, causes
a very serious disease of beet producing
spots on the leaves. It is common and de-
structive in America and Europe. The
conidiophores usually, though not always,
emerge from the sto-
mata from a few-celled
stroma and are amphig-
enous. They vary in
length and _ septation

with age. If in humid Fre. 426.—C. api, After

atmosphere the spots Dusear and Bailey.

become hoary, due to the large number of
spores present. Each cell of the spore is
capable of germination. The germ tubes
infest the host through the stomata. Pure
Fic, 427.—Fertile hy- cultures of the fungus may readily be se-

preg and spores of cured by the usual methods. Here the

Dugear. mycelium produces dense matted colonies
of deep olive color and a greenish-grey aérial growth but no
conidia. Found also on Spinach in Texas.

THE FUNGI WHICH CAUSE PLANT DISEASE 629

C. flagelliformis E. & H.

Spots amphigenous, indefinite, yellowish; conidia very long,
curved, tapering.

The cause of spinach leaf spots.

C. citrullina Cke.

Epiphyllous, spots orbicular, 2-4 mm. in diameter, white with a
purple margin; conidiophores elongate, terete, pale olivaceous,
conidia very long, attenuate above, few-septate, hyaline, 120-140
x3n.

The cause of leaf spots on watermelon.**?

C. cucurbite E. & E.!4

Spots amphigenous, rounded, subochraceous, becoming thin and
white, 1 to 4 mm. in diameter, border slightly raised; conidiophores
tufted, olive-brown, 70-80 x 4 uw, continuous, subgeniculate
above, apically obtuse; conidia linear clavate, 100-120 x 3-4 u,
hyaline, septate.

On cucumbers in America, associated with Phyllosticta cu-
curbitacearum. .

C. melonis Cke. grows on cucumbers and melons in England
and New Zealand. What is probably the same fungus has been
set up by Giissow 4 as a new genus Corynespora.

C. armoracie Sacc.

Spots amphigenous, pale; conidiophores short, simple, 30-40
x 5 pw; conidia rod-shaped, cuspidate, 100-120 x 5 u, hyaline,
multiseptate.

On horseradish.

C. bloxami B. & Br. occurs on Brassica.

C. personata (B. & C.) E.

Spots hypophyllous, small, brown, orbicular, 2-4 mm. or more
in diameter; conidiophores densely tufted, short, brown, con-
tinuous; conidia clavate, pale-brown, about 3 to 4-septate, 30-
50 x 5-6 u.

On the peanut in the Southern United States and West Indies.*®

C. cruenta Sacc. ,

Spots amphigenous, indefinite, reddish; conidiophores, subfasci-
culate, simple, subdenticulate, light olivaceous; conidia obclavate,
curved, 60-80 x 4 uy, subacute, 6 to 7-septate, hyaline or oliva-
ceous.

630 THE FUNGI WHICH CAUSE PLANT DISEASE

On cowpea and bean in America. Usually causing but slight
damage.

C. vigne Rac. (not E. & E.) is described as injurious to the
cowpea in Java.**4

C. medicaginis E. & E.

Spots amphigenous, smoky to black, 0.5-5 mm. in diameter,
orbicular, indefinite; conidiophores subhyaline, becoming brown-
ish, continuous, geniculate, 35-45 x 4-5 yu; conidia cylindric-
fusoid, 3 to 6-septate, 40-60 x 3 y.

On alfalfa and crimson clover.**®

C. ariminensis Br. & Cav. is found on sulla leaves;

C. saccharii Br. d. H. C. longipes Butler, C. acerosum D.
& H., C. vagine St and C. kopkei Krug. are on sugar-cane.

C. capparidis Sacc. is found on caper.

C. asparagi Sacc. & C. caulicola Wint. affect asparagus.

C. malkoffi Bubak causes an anise disease in Sadova.

C. thee v. Br. d. H. occurs on tea in India;

C. viole Sacc. ‘

Spots amphigenous, rounded, bleached; conidiophores short,
simple, greyish, 30-35 x 4 y; conidia long and slender, rod-
shaped, multiseptate, hyaline, 150-200 x 3.5 yu.

It produces a violet leaf spot.”

C. althzina Sace. occurs on hollyhock.

Spots amphigenous, brown, 2-4 mm. broad; conidiophores
fasciculate, slender, 40 x 5 yu, few-septate, olive brown; conidia
apical, cylindric, to obclavate or broadly fu-
soid, straight, 40-60 x 5 uy, apically obtuse,
2 to 5-septate, hyaline.

C. kellermanii Bub.

Spots amphigenous, irregular, angular, olive-
brown, up to 1 cm. across; conidiophores fas-
TARO ap ciculate, slender, few-septate, 150 u x 4-5 uy,
Fig. 428.—C. rosecola. Olive-brown; conidia filiform, 50-150 x 4-5 y,

After Southworth. 5 to 15-septate, straight or curved, hyaline.
: It also occurs on hollyhock and is nearly related to C. malvarum

ace.

C. rosicola Pass.”

Spots ochraceous, fuscous-margined, 2-3 mm. in diameter;

THE FUNGI WHICH CAUSE PLANT DISEASE 631

conidiophores cespitose, small, densely gregarious, fuliginous,
subcontinuous, 20-40 x 3-5 u, conidia cylindric, straight, short,
30-50 x 3.5-5 yu, subfuscous, 2 to 4-septate.

On roses.

C. hypophylla Cav. on roses in Europe is very like the preceding
species.

C. omphacodes E. & H. and C. phlogina Peck. are the causes of
rather unimportant leaf spots of cultivated phlox.

C. neriella Sacc. is on oleander.

C. sordida Sacc. produces leaf spots and defoliates Tecoma.

C. angreci Roum. is on orchids;

C. cheiranthi Sacc. on Cheiranthus.

C. brunkii E. & G. is reported on the geranium (Pelargonium
zonale.)

C. resede Fel.3

Spots punctiform, greyish; conidiophores fasciculate, simple,
continuous or few-septate, 50-70 x 4-5 yu, fuscous; conidia apical
to linear, obclavate, 4 to 5-septate, hyaline, 100-140 x 2.5-3 x.

Spots are caused on the mignonette and the plants are blighted.
The hyphe appear through the stomata.

C. odontoglossi P. & D. occurs on cultivated Odontoglossum;

C. unicolor S. & P. on lily.

C. richardiecola Atk.”

Spots amphigenous, black, with small white centers, subcircular,
2-6 mm. broad; conidiophores fasciculate, light-brown with a
reddish tinge, becoming reddish-brown, erect or apically flexuose,
denticulate, 30-80 x 5 uw; conidia hyaline, obclavate, 4 to 10
or more septate, 50-100 x 34 u.

On calla lily.

C. microsora Sacc.**

Spots amphigenous, minute, brown, gregarious; conidiophores
subfasciculate from a tubercular stroma, short, continuous, sub-
olivaceous, 20-30 x 3 uy; conidia filiform, 3 to 5-septate, con-
stricted at the septa, olivaceous, 35-45 x 3.5 yu.

It causes spotting and defoliation of Tilia.

C. cercidicola E.

Spots amphigenous, dull grey above, rusty-brown beneath, .
with a blackish-brown raised border; conidiophores amphigenous,

632 THE FUNGI WHICH CAUSE PLANT DISEASE

fasciculate, brown, 90-114 x 3.54 y, subgeniculate above; conidia
oblong, clavate, faintly 3-septate, 30-40 x 5-7 yu.

It seriously injures the Japanese red-bud and occurs also on the
American species.**

C. acerina Hartig is on maple seedlings.

C. sequoia E. & E.

Large compact olivaceous tufts are formed on languid leaves;
conidiophores ferruginous, brown, abruptly bent, subnodose,
toothed, sparingly septate, 50-70 x 4-5 u; conidia oblong, becom-
ing clavate, 40-70 x 6 u, concolorous with the hyphe, 3 to 5-septate,
constricted at the septa.

It is said to seriously interfere with the growth of Sequoia in
the eastern states.

C. halstedii E. & E.

Spots hypophyllous, indefinite, brownish to olivaceous, 2-4 mm.
across; conidiophores few-septate, 100-150 x 5-7 yu, undulate or
crisped; conidia obclavate, 65-80 x 5-7 y, 3-septate, somewhat
constricted.

It produces blotches on pecan leaves and causes partial de-
foliation.”

Stilbacez (p. 565)

Sterile hyphe creeping, scanty; fertile hyphe collected into a
stalk-like or stroma-like fascicle, bearing conidia at the top, more
rarely along the sides, pale, bright-colored or dark.

Key to Sections or Stilbacee

Hyphe and conidia hyaline or light

Colored sic. sessed co vesaeeeasexces I. Hyalostilbez.
Conidia globose, elliptic or oblong
Vecelled sake sasains vedo e votes ban 1. Amerospore, p. 633.
Seed: 3ogcs caer Beereda wees 2. Didymospore.
3 to several-celled................ 3. Phragmospore.
Conidia filiform, coiled............... 4. Helicospore.
Hyphe or conidia dark................ II. Pheostilbee.

Conidia globose, elliptic, or oblong,
With cross walls only

celled: sip swmaneadecemet aus 5. Amerospore, p. 635.

THE FUNGI WHICH CAUSE PLANT DISEASE 633

2-celled os esiia ties eee sewer ey 6. Didymospore.
3 or more-celled.. ............... 7. Phragmospore, 637.
Muriform ...................00005 8. Dictyospore.
Conidia of a stellately arranged group of
CAS ius un. iewinin- eee date aise ene 9. Staurospore.

Hyalostibez-Amerospore (p. 632)

Bright or light-colored, conidia globose, elliptic or oblong,
continuous.

Key To Genera or Hyalostibeex-Amerospore

Conidial part distinctly capitate or at least
terminal
Conidia not in chains
Head of conidia not gaping or split-
ting above
Head not spiny
Conidiophores of head normal
Conidia covered with mucus
Synnema monocephalous
Conidiophores dendroid-
verticillate
Without distinct sterig-
MAGA cise ig egisae spade 1. Dendrostilbella.

Matai conc cite cioree 2. Pirobasidium.
Conidiophores not dendroid-
verticillate............ 3. Stilbella, p. 635.
Synnema polycephalous
Capitula on extremely

short branches. ..... 4. Polycephalum.
Capitula on spreading

subulate branches... 5. Tilachlidium.
Capitula on erect

branches ........... 6. Corallodendron.

Conidia without mucus
Synnema monocephalous
Conidiophores spirally -
twisted............. 7. Martindalia.

634

Conidiophores more or less
straight

Conidia rhombic or

biconic. ..........

Conidia globose to fu-

soid

Synnema polycephalous

ee eee wre wwe e ae

Terrestrial, large, 1-2 cm.;.

conidia ovoid
Not terrestrial, small; co-
nidia elongate-ovate. .
Conidiophores conidium-like, sep-
tate; monocephalous......
Head spiny with radiating spic-
ules
Spicules conic, granulate
Spicules with many
branches at middle
Head of conidia persistent below,
splitting above... .............
Conidia in chains
Synnema with conidia above; conidia
without mucus
Synnema not pubescent... .......
Synnema pubescent..............
Synnema with conidia below; conidia
with mucus. ..............005
Conidial part cylindric or long-clavate
Conidia more or less equally scat-
tered
Sterigmata denticulate, branched....
Sterigmata none or simple..........
Conidia in lateral heads or racemes
Conidia in racemes; synnema lo-
Dated vs eee oem trerencaaueiakgcnma
Conidia in heads
Conidiophores with lateral nodes,
usually escaping through the
Stomata.......... cee eee
Conidiophores without nodes, usu-
ally entomophilous..........

curved

15.

16.
17.

18.

19.

20.

21,

22.

. Rhombostilbella,

THE FUNGI WHICH CAUSE PLANT DISEASE

. Ciliciopodium.

. Macrostilbum.
. Chondromyces.

. Atractiella.

. Actiniceps.

. Heterocephalum.

Pilacre.

Coremium, p. 635.
Lasioderma.

Microspatha.

Cladosterigma.
Isaria, p. 635.

Peribotryum.

Helostroma.

. Gibellula.

p- 635

THE FUNGI WHICH CAUSE PLANT DISEASE 635

Stilbella Lindau (p. 633)

Hyphe forming a coremium which is capitate above; conidio-
phores borne on the cap; conidia small, often enclosed in slime.

Over one hundred species chiefly saprophytes. (Commonly
known as Stilbum but the type of the genus being a hymenomycete
it was renamed.)

S. flavida (Cke.) Kohl. causes a serious coffee disease.

S. thee Bern. is on tea in India.

S. nanum Mas. causes the thread blight of tea.

S. populi on poplar =Mycospherella populi. See p. 250.

Rhombostilbella Zimmermann (p. 634)

Synnemata verticillate-stilbiform; conidia rhomboid to biconic,
acute, without mucus. Monotypic.

R. rose Zimm. is found on Liberian coffee.**

Coremium Link (p. 634)

Coremium cylindric, apically enlarged and
fertile; conidia very small, catenulate. A
small genus. In part =Rosellinia and Penicil-
lium. See p. 230.

Isaria Persoon (p. 634)

Stromata erect, clavate or branched, fer-
tile throughout, hairy; conidia small, globose
to ellipsoid, hyaline.

Over one hundred species, chiefly entomog-
enous.

I. fuciformis Berk. is reported from Eng-
land and Australia forming its stromata :

7 Fie. 429.—-Coremium
on the inflorescences of Festuca. glaucum. After

I. graminiperda B. & M. also causes con- Corda.
siderable injury to grasses in Australia.

Pheeostilbez-Amerospore (p. 632)

Dark conidia continuous, globose to elongate.

636 THE FUNGI WHICH CAUSE PLA

NT DISEASE

Key to Genera or Pheostilbes-Amerospore

Conidia not in chains
Synnema setose.. 20... 0. ese e eee ee eee 1.
Synnema naked

Conidia asperate, on minute basidia... 2.

Conidia smooth

Synnema carnose, racemose-branched 3.

Synnema fibrous or corneous, not
racemose
Conidiophore lageniform. ........ 4.
Conidiophore lacking, at least not
lageniform
Synnema stalked, fibrous
Conidia dark, globose to ellip-

Conidia hyaline

Conidia ovoid to oblong... 6.
Conidia elongate or falcate. 7.
Synnema sessile, corneous...... 8.

Conidia in chains

Synnema setose.. ..........cceeeeeees 9.

Synnema not setose
Stalk branched above ............00- 10.
Stalk simple or nearly so
Capitule loose
Base of synnema subequal; usually

OD GLENS ys ena se stews ees as ll
Base of synnema perithecioid;
usually on leaves. ........... 12

Capitule compact
Conidia globose

Saccardea.

Basidiella.

Stilbothamnium.

Ceratocladium.

. Sporocybe.

Graphium.
Harpographium.
Glutinium.
Trichurus.

. Stemmaria.

. Stysanus, p. 636.

. Graphiothecium.

Conidia echinulate. ........... 13. Harpocephalum.
Conidia smooth
Conidia pleurogenous....... 14. Heydenia.
Conidia acrogenous. ........ 15. Briosia.
Conidia ovoid to oblong. ........ 16. Antromycopsis.
Stysanus Corda

Stromata erect, cylindro-clavate, dark, rigid; conidia in an oblong

THE FUNGI WHICH CAUSE PLANT DISEASE 637

or subglobose panicle, ovoid, lemon-shaped or fusoid, subhya-
line.

Some twenty-five species. See Fig. 430.

S. veronice Pers. occurs on cultivated Veronicas in Italy;

S. ulmariz M’W. on Spirea in Ireland.

S. stemonitis Cda. causes a brown rot of potatoes in storage.

Pheostilbeze-Phragmospore (p. 633)

Conidia 3 to several-celled, oblong to cylindric, dark or hya-
line.

Key To Genera or Pheostilbee-Phragmospore
Conidia capitate

Synnema simple
Synnema black; conidia densely capi-
Pate ee oy. wahie a Mont bacok aeons 1. Arthrobotryum.
Synnema fuscous or pale; conidia
loosely capitate. ................ 2. Isariopsis, p. 637.
Synnema dendroid-branched. .......... 3. Xylocladium.
Conidia not capitate
Conidia catenulate. ...............0005 4, Dendrographium.
Conidia not catenulate
Stalk fibrous
Synnema simple or branched; conidia
acro-pleurogenous. ........... 5. Podosporium.
Synnema branched; conidia acro-
BONOUSs oceans ete a genase tee aie 6. Negeriella.
Stalk parenchyma-like
Conidia pleurogenous, on a disk. ... 7. Riccoa.
Conidia acrogenous. .............. 8. Podosporiella.

Isariopsis Fries

Slender, dark or subhyaline, cylindric hyphe laxly aggregated;
conidia in a lax panicle or head, cylindric or clavate. See Fig. 431.

I. griseola Sacc.

Spots hypophyllous, ochraceous; coremium stipitate, dense.
200 x 30-40 y, composed of filiform hyphs; conidia borne on
the reflexed ends of the hyphs, cylindric-fusoid, curved, 50-60
x 7-8 y, grey, 1 to 3-septate, constricted.

It causes disease of beans.

638 THE FUNGI WHICH CAUSE PLANT DISEASE

Tuberculariacez (p. 565)

Hyphe compacted into a globose, discoid, or verruciform body,

b>

Fic. 430.—Stysanus. Fia. 431.—Isariopsis.
After Saccardo. After Saccurdo.
the sporodochium; sporodochia typically sessile, waxy or subge-
latinous, white, bright-colored or dark to black.
In part=Nectria, Claviceps and Hymenoscypha, etc. See

pp. 146, 201, 211.
Key To Sections or Tuberculariaces

Hyphe and conidia hyaline or bright-colored I. Mucedinee.
Conidia globose to fusoid or falcate

Conidia continuous. ................ 1. Amerosporee, p. 639.
Conidia l-septate. ..............000. 2. Didymospore.
Conidia 2 to many-septate........... 3. Phragmospore, p. 645.
Conidia muriform. ................. 4. Dictyospore.

Conidia spirally coiled................. 5. Helicospore.

Conidia forked or cruciate. ............ 6. Staurospore.

Hyphe olive to brown or black; conidia

concolorous, rarely hyaline. ......... II. Dematiez.

Conidia globose to elongate
Conidia continuous. ................ 7. Amerospore, p. 654.

Conidia 1-septate...............0... 8. Didymospore.

THE FUNGI WHICH CAUSE PLANT DISEASE 639

Conidia 2 to many-septate........... 9. Phragmospore, p. 657.
Conidia muriform.................. 10. Dictyospore, p. 658.
Conidia filiform, hyaline............... 11. Scolecospore.
Conidia spirally twisted............... 12. Helicospore.
Conidia angulose-stellate.............. 13. Staurospore.

Tuberculariaceze-Mucedinez-Amerospore (p. 638)

Conidia hyaline, or bright-colored, continuous, globose to fusoid;
hyphe hyaline.

Key To GENERA OF Tuberculariacee#-Mucedinex-Amerosporere

Sporodochia smooth or nearly so
Conidiophores normal
Conidia muticate
Conidia not covered with mucus
Conidia not acrogenous-capitate

Sporodochium girt by a heterogenous
CUDs weg he aiads detested eau 1. Patellina.

Sporodochium without a heterogenous

cup
Conidia not catenulate or scarcely so
Conidia escaping from interior of

hyphe
Conidiophores branched. ........ 2. Endoconidium, p. 641.
Conidiophores simple............ 3. Trichotheca.

Conidia arising on outside of hyphe
Conidiophores lacking
Conidia large, pellucid

Conidia globose... ............ 4, Spherosporium.
Conidia oval. .............5-5 5. Diaphanium.
Conidia small, not pellucid...... 6. Pactilia.

Conidiophores present
Conidia pleurogenous or acro-

pleurogenous
Conidia globose. .............- 7. Beniowskia.
Conidia ovoid to oblong. ...... 8. Tubercularia, p. 642.
Conidia fusoid to cylindric..... 9. Fusicolla.

Conidia acrogenous

640 THE FUNGI WHICH CAUSE PLANT DISEASE

Conidiophores verrucose. ...... 10. Dacrymycella.
Conidiophores not verrucose
Uredinicolous............... 11. Tuberculina.
Not uredinicolous
Sporodochia globose
Conidia globose; conidio-
phores short. ......... 12. Hgerita.
Conidia ovoid; conidiophores
branched. ............ 13. Granularia.
Sporodochia pulvinate
Conidia acicular........... 14. Kmetia.
Conidia terete-oblong. ..... 15. Bactridiopsis.
Sporodochia disk-shaped. .... 16. Hymenula.
Sporodochia cupulate.. ..... 17. Hyphostereum.
Sporodochia verruciform or
effuse

Conidiophores simple
Conidiophores radiate,
united at base
Conidiophores not arising
from a cellular mass.. 18. Clinoconidium.
Conidiophores arising from

a cellular mass. ..... 19. Ustilaginoidea, p. 643.
Conidiophores not united or
radiate. ............. 20. Sphacelia, p. 643.
Conidiophores dendroid
branched. ............ 21. Dendrodochiun, p. 643.
Conidia in chains
Conidia covered with mucus. . .. 22. Collodochium.

Conidia without mucus
Conidia globose
Conidia hyaline... ........... 23. Spherocolla.
Conidia blue. ............... 24. Sporoderma.
Conidia elliptic to oblong
Sporodochium disk-shaped,

orange-red ............. 25. Necator, p. 643.
Sporodochium subglobose,
whitish. ................ 26. Patouillardia.

Conidia cylindric
Sporodochium dilated above,
stalked.................. 27. Bizzozeriella.

THE FUNGI WHICH CAUSE PLANT DISEASE

Sporodochia globose to verruci-
form

Sporodochia gelatinous, sessile
Sporodochia not gelatinous,
short-stalked...........
Conidia acrogenous-capitate; sporo-
dochia turbinate................

Conidia covered with mucus
Sporodochium globose, hardened......
Sporedochia verruciform or subeffuse. .
Sporodochia discoid. ................

Conidia ciliate
Conidia 1-ciliate at base only..........
Conidia 1-ciliate at each end. .........
Conidia 7 to 8-ciliate at each end......
Conidiophores with internal conidia-
bearing areoles. .................0..
Sporodochia setulose, ciliate or uniformly
woolly

Sporodochia woolly or setulose

Sporodochia setulose; conidia catenu-

Sporodochia woolly or velvety; conidia
capitate
Conidia globose. . ............2eeeees
Conidia oblong.................e0ee
Sporodochia ciliate at the margin
Sporophores none; conidia coacervate... .
Sporophores distinct
Conidia in chains...................-
Conidia not in chains
Conidiophores 6-ciliate above, united
below) 4/c4 ieee etoxsae ease as
Conidiophores not ciliate or united. ...

43.
44.

641

. Cylindrocolla.

. Spheridium.

. Cephalodochium.

. Thecospora.
. Iosporium, p. 643.

. Epidochiopsis.

. Stigmatella.

. Thozetia.

. Chetospermum.

. Scoriomyces.

. Periola.

. Dacryodochium.
. Lachnodochium.

. Volutellaria.

. Volutina.

Guelichia.
Volutella, p. 644.

Endoconidium Prillieux & Delacroix (p. 639)

Sporodochia pulvinate, white; conidiophores hyaline, racemose;
conidia hyaline, rounded, formed within the conidiophore and

escaping apically.
A small genus, chiefly saprophytes.

642 THE FUNGI WHICH CAUSE PLANT DISEASE

E. temulentum P. & D.=Hymenoscypha temulenta. See
p. 146.

Tubercularia Tode (p. 639)

Sporodochium tubercular or wart-like, sessile or subsessile,
smooth, rarely with bristles, usually reddish; conidiophores very

\\ \
Wide
ER

Fie. 432.—Hyphz
of Tubercularia,

bearing conidia. Fic. 433.—T. fici, sporodochium, showing setz
After Durand. and conidial formation. After Edgerton.
slender, usually branched; conidia apical, ovate to elongate. In
part =Nectria. See p. 201.
Over one hundred species, chiefly saprophytes.
T. vulgaris Tode =Nectria cinnabarina. See p. 202.
T. fici Edg.7™ 6
Sporodochia scattered or gregarious, superficial or subcuticular,
light pink, variable in size up to 3-4 x 1-1.5 mm., smooth, irregular
in outline; conidiophores crowded, hyaline, 20-27 x 1-2 up;
conidia small, clear, elliptic to oval, regular in size, 5-7 x 2.5-5 mu;

THE FUNGI WHICH CAUSE PLANT DISEASE 643

sete scattered or abundant, variously placed, straight or curved,
hyaline or subhyaline, septate, papillose, 60-90 x 4-6 p.
It is the cause of a fig canker.

Tuberculina Saccardo

Several species occur in sori of the Uredinales.

Ustilaginoidea Brefeld, a small genus of Ascomycetes, one species
of which, U. virens, on rice is known only in the conidial stage.
See p. 214.

Sphacelia Léviellé (p. 640)

Sporodochia planose, effuse, stromate or sclerotioid; conidio-
phores short, simple, filiform; conidia apical, ovate.

A small genus, chiefly conidia of Claviceps and related genera.

S. segetum Lév. =Claviceps purpurea. See p. 212.

S. typhina (Pers.) Sacc. =Epichloe typhina. See p. 210.

Dendrodochium Bonardin (p. 640)

Sporodochium pulvinate or verruciform, white or light-colored;
conidiophores verticillate, branched; conidia acrogenous, ovoid to
oblong.

A genus of about forty species.

D. lycopersici March is found on tomatoes in Belgium.*®

Necator Massee (p. 640)

Sporodochium erumpent, small, slightly convex, becoming
orange-red; conidia oblong or elliptic, catenulate, contents orange.
Monotypic.

N. decretus Mas. is a dangerous parasite of coffee, tea, etc.55* 364

Ilosporium Martius (p. 641)

Sporodochia wart-like, pulvinate or subeffuse, white or light-
colored, subgelatinous or waxy; conidiophores variable; conidia
globose, sigmoid, variable, embedded in mucous. There are some
forty species.

I. malifoliorum Shel.

Spots suborbicular or coalescing and becoming irregular, brown

644 THE FUNGI WHICH, CAUSE PLANT DISEASE

or mottled with gray and with a small gray spot near the center,
5-15 mm. in diameter; sporodochia hypophyllous, minute, gelat-
inous, yellow-amber, becoming black, spherical, becoming discoid
or irregular, 150-160 » in diameter; conidio-
phores branched; conidia oblong, 1-3.5 x 4 pz.
It is said by Sheldon * to be one of the most
common and destructive causes of leaf spots of
the apple often resulting in nearly complete de-
= foliation. In the centers of the leaf spots other
Fig. 434.—“Illospo- spots bearing other species of fungi are often
After Saccardo. found, leading to the thought that perhaps the
Illosporium in such cases results from secondary infection in the
wounds made by the earlier fungus. The sporodochia are hypo-
phyllous, often hidden by the normal pubescence of the leaf.

Volutella Tode (p. 641)

Sporodochia discoid, regular, margin ciliate, sessile or stipitate;
conidiophores usually simple; conidia ovoid to oblong.

Some seventy species.

V. leucotricha Atk.

Sporodochia convex-discoid, white to pale flesh-color; sete few,
filiform, few-septate, subhyaline; conidiophores densely fasciculate,
filiform; conidia oblong.

On cuttings in greenhouses.

V. fructi S. & H.

Spots on the fruit, circular; sporodochia, numerous in concentric
circles, subcuticular,
erumpent, elevated 200-
250 yw, 150-400 yw in
diameter; mycelium
black; sete distributed
throughout the sporodo-
chium, black, 0 to 3-

Fic. 435.—V. fructi. Sporodochia in section.
septate, acute, smooth, After Stevens and Hall.

100-400 x 5-8 yu; co-

nidiophores elongate, hyaline, simple, 25-35 x 3 u; conidia
smooth, oblong-fusoid to falcate-fusoid, hyaline or sub-olivaceous,
17-23 x 2.5-3.5 p.

THE FUNGI WHICH CAUSE PLANT DISEASE 645

It is the cause of a dry rot of apples.* 37

V. dianthi (Hal.) Atk.?!

It is the cause of anthracnose of carnation.

The acervuli are conspicuous with black sete.

V. concentrica Hals. is reported by Halsted as the cause of leaf
spots of Bletia.?!

Tuberculariacez-Mucedinea-Phragmospore (p. 638)

Hyphe hyaline; conidia 2 to several-septate, hyaline or bright-
colored, fusoid to faleate, rarely short and simple in some species
of Fusarium.

Key To Genera or Tuberculariacee-Mucedinee-Phragmospore

Conidia somewhat catenulate, cylindric.... 1. Discocolla.
Conidia rarely catenulate
Conidia cruciately 4-celled; sporodochium
gelatinous. . 0.2.2... ... eee eee eee 2. Sarcinodochium.,
Conidia not cruciate
Conidiophores short, simple
Conidia very large, terete-oblong... 3. Bactridium.
Conidia doliform.................. 4. Pithomyces.
Conidiophores more or less branched
Conidiophores dichotomous; conidia
keyshke.s 0. Hae dice weer aens 5. Heliscus.
Conidiophores usually verticillately
branched, conidia usually fal-
cate, sometimes oblong
Sporodochium gelatinous. ....... 6. Pionnotes, p. 645.
Sporodochium waxy or byssoid... 7. Fusarium, p. 646.

Pionnotes Fries

Sporodochium gelatinous, then firm, orange, pulvinate or lobed;
conidiophores fasciculate, simple or branched; conidia rather large,
fusoid to cylindric, curved.

Only twelve or fifteen species, chiefly saprophytes.

P. betz Mas. occurs on mangels and beets and according to
Massee is probably identical with P. rhizophila which attacks
stored Dahlia roots and potatoes.

646 THE FUNGI WHICH CAUSE PLANT DISEASE

Fusarium Link (p. 645)

Sporodochium pulvinate, or subeffused; conidiophores branched ;
conidia terminal, solitary, fusiform or falcate, more or less curved,
pluriseptate.

In part=Nectria, Neocosmospora, Gibberella. See pp. 201,
205, 206.

This is a large genus, (some four hundred species have been de-
scribed) though future study will undoubtedly relegate many
names to synonymy.

Many of the species are destructive parasites, invading the ducts
of plants and by stoppage of the water-supply causing the class of
diseases known as “‘wilts.’”’ Others induce rot, spotting, cankers,
etc. Taken as a whole the genus is one of the most injurious with
which plant pathology has to do.

It seems probable that some of the forms that live normally as
saprophytes in soil may encroach upon living roots of susceptible
plants when these are available.

In nature the spores typical of this form-genus are borne in
sporodochia, coremia or acervuli and are crescent-shaped or fusoid.
The same mycelium that produces these structures often, indeed
usually, produces also similar and smaller conidia scattered
on single hyphe (=Cephalosporium). These two forms are called
macroconidia and microconidia respectively. The microconidia
are regarded by Appel & Wollenweber ** as depauperate mac-
roconidia. Frequently chlamydospores form in the mycelium;
either terminal or intercalary. Sclerotia are also not uncom-
mon.

Undoubted species of Fusarium have been shown to belong to
several different Hypocrealous ascomycetes, while still more have
as yet revealed no ascomycete connection.

Biologic specialization has been found, in that forms morpho-
logically indistinguishable are frequently incapable of cross in-
oculation onto other than their usual hosts.

Fusarium grows well in culture and the species often show
marked differences in growth on various media, particularly in
the colors that are developed.

As with the anthracnoses much study is here needed to throw

=

647

THE FUNGI WHICH CAUSE PLANT DISEASE

“ra
‘ummsoulgiqni “7

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‘sarveds JUaLeyIp al ein}Beaino guraoys un

‘CUNTULAPIP “7
liweng jo salodg—'gep ‘org

648 THE FUNGI WHICH CAUSE PLANT DISEASE

light on the inter-relation of the various species and their hosts.
Apple & Wollenweber ** have made an extensive study of several
species to lay the ground for a monograph. They conclude that
in delimiting species important characters are the forms of the
conidia, especially their bases, apices, and degree of curvature and
septation (see Fig. 436); the color of the mycelium and spores;
the presence or absence of chlamydospores. They cast aside as
valueless many earlier descriptions substituting new diagnoses
and new names. According to their conception, the following
names should stand.

F. solani (Mart.) Sacc. =Fusisporium solani Mart. =Fusarium
commutatum Sacc.

F. martii A. & W. =Fusisporium solani Mart.

F. ceruleum Lib. = Fusarium solani.

F. discolor A. & W. =Fusarium solani.

F. rubiginosum A. & W. =lusarium solani.

F. discolor var. sulphureum (Schl.) A. & W.=Fusarium sul-
phureum Schlecht.

. Subulatum A. & W.

. metachroum A. & W.

. orthoceras A. & W. =F. oxysporum Sm. & Sw. not Schl.

. theobrome A. & Struk. oer

. wilkommii Lin. =F. bacilligerum B. & Br. a

. falcatum A. & W. =F. vasinfectum pisi Schk. Fae:

F. gibbosum A. & W. 2

It will be noted that several of the species mentioned below
are here involved.

F. platani Mont. =Calonectria pyrochroa. See p. 205.

F. rubi Wint.

Mycelium white, becoming pink, especially
abundant on the flowers; conidia elongate, 1
to 8-septate, variable in size and form,
aa eee straight or curved, 14-30 x 3-3.5 y, not con-

ovary showing my- stricted.

Shean sl ge Cook * *73 found this fungus in diseased

Cook. buds of dewherries and by inoculation dem-
onstrated that it is responsible for witches-broom, double-
blossom, and similar abnormal growths of this plant.

tx} rf a} a) bx} bay

THE FUNGI WHICH CAUSE PLANT DISEASE 649

F. gemmiperda Aderh. is described by Aderhold *” as fatal to
flower buds of cherry before they open, a conclusion supported by
inoculation experiments. The disease in general appearance re-
sembles sclerotiniose.

F. rhizogenum P. & C.

Sporodochia superficial, 1 to 2 mm. wide, dense, convex, white
or whitish, hyphe densely interwoven, septate, subramose; conidia
oblong, roundish, '1-septate, 70 x 4 p.

It was originally described as a parasite on apple roots in Ne-
braska *”? and is mentioned by Aderhold ® as the cause of death of
roots of apple and cherry trees in Europe. The mycelium grows
within the roots and gummosis of the wood occurs. A Cephalo-
sporium form is known, also chlamydospores.

F. putrefaciens Osterw.*’""5 is said by Osterwalder *”4 to cause
decay of pomaceous fruits.

F. cubense E. F. Sm. was isolated from bananas affected with
blight. Inoculation showed the fungus capable of growing through
the bundles for long distances.*”

F. limonis Bri.! 37% 437

Sporodochia gregarious, confluent, white; hyphz spreading,
branched, septate; conidiophores erect, with alternate or opposite
branches; conidia variable, acrogenous, continuous to 3-septate,
oblong to fusiform, curved, pointed, slightly constricted, 26-27 x
2.4-2.8 p.

This fungus is held to be contributory to, if not sasponsiile for,
the Mal-di-gomma or foot-rot of citrous
fruits which is known practically wherever
these fruits are cultivated.

F. culmorum (W. Sm.) Sacc.8 35

Reddish-yellow, gelatinous, effuse; hyphe
few-septate, tortuous; fertile, short, con- eA
tinuous; conidia fusoid-falcate, 3 to 5-sep-
tate, 28-32 x 6-8 » on wheat. Fig. 438.—F. culmorum.

The fungus affects chaff and seed, first aver Chester:
appearing as a whitening of the upper halves of the glumes fol-
lowed later by a pink color. The glumes become cemented to-
gether and the whole head may be involved. The grains are of
light weight and are often covered with the fungus. Chester

650 THE FUNGI WHICH CAUSE PLANT DISEASE

showed that the mycelium penetrates the seed and may even
consume it entirely.

F. sp. occurs on raspberry.2%

F. moniliforme Shel.

Sporodochium subeffuse, salmon-pink; conidiophores simple
or with opposite branches; microconidia continuous, oblong-ovoid,

bRded
Fic. 439.—Fusarium Fic. 440.—F. vasinfectum. A. Macro-
on corn. After conidia. B. Portion of a hypha.
Burrill and Bar- C. A germinating macroconidium.

“rett. After Reed.

moniliform, 6-10 » long; macroconidia falcate, acute, usually
3-septate, 25-40 py long.

It causes molding of corn.3”

Several other undetermined species have been isolated from
corn on which they occur as the cause of dry rot of the grain.1™

A fusarium on banana is by Essed referred to Ustilaginoidella.
See p. 214.

F. vasinfectum Atk.*8*8
Hyphe at maturity yellowish, 2-4 u in diameter; conidia borne

A= > = singly; microconidia oval, con-
0 O. te tinuous; macroconidia falcate, 2 to

= B-septate, 1-2 x 2-4 p.
aes is Atkinson *! first described this

Pies _ on cotton and okra in which
croconidia. E. Cy eee plants it was found plugging the
After Reed. ducts with its mycelium. The

mycelium here was 2-4 p» in diameter and microconidia were

seen within the ducts. Pure cultures were obtained and inocula-
tions with these on plants already injured by Pythium resulted in

THE FUNGI WHICH CAUSE PLANT DISEASE 651

infection. The ascigerous stage was said by Smith ® to be a
Neocosmospora and the many wilts caused by Fusarium have by
various authors who follow
Smith been reported as
Neocosmospora though
without real evidence that
they are such. See
page 205.

Recent studies of Hig-
gins ** and Butler 8 in-
dicate that the Fusarium
of the Neocosmospora is
a saprophyte and that the
Fusariums parasitic in the
wilt diseases are as yet
unknown in _ascigerous
form.

The Fusarium parasitic
on cotton is believed to Fic. 442.—F. vasinfectum, showing thrombosis
be identical with that on i aaa
okra but distinct biologically if not morphologically from that
of watermelon.

F. vasinfectum var. tracheiphila E. F. Sm.

This form on cowpea, which appears to be morphologically
identical with F. vasinfectum is not capable of infecting cot-
ton.

F. niveum E. F. Sm. is the cause of the watermelon
wilt. Morphologically it is like F. vasinfectum.

A fungus regarded by Reed ®* *° as identical with this was also
described as causing wilt of ginseng.

F. vasinfectum var. pisi v. Hall has been described as a variety
affecting the pea.*® 37

F. udum Butler on pigeon pea in India is closely related to
this last fungus.

F. aurantiacum (Lk.) Sacc. is recorded for cucurbs occurring
on stems, leaves and fruits.

CF. oxysporum Schl.%% 396
' Sporodochia convéx, subverrucose, rose, erumpent, confluent;

390, 392-394

652 THE FUNGI WHICH CAUSE PLANT DISEASE

conidia on short conidiophores; microconidia continuous, elliptic;
macroconidia falcate-fusoid, 3 to 4-septate, 40-60 x 7-8 u.

Smith and Swingle ** mention 11 described species of Fusarium
recorded by Saccardo for the Irish potato, viz.;

Fusarium oxysporum Schl., F. (Fusisporium) solani (Mart.)
Sace., F. (Fusisporium) solani-tuberosa Mart., F. didymum
Harting, F. solani Schl., F. (Fusisporium) roseolum (B. &. B.)
Sacc., F. violaceum Fel., F. ceruleum (Lib.) Sacc., F. diplosporum
C. & E., F. commutatum Sacc., F. pestis Sorauer, F. eruginosum
Delacroix, F. acuminatum E. & E., F. affine Fautr. & Lamb, all
of which they tentatively regard as synonyms, attributing such
differences as have been noted in descriptions to variations in the
environment under which the fungus was growing when described.
The potato disease caused is common over a considerable portion
of the United States and is variously known as “bundle blacken-
ing,” “stem rot,” “dry end rot,” and “dry rot.”

The fungus grows readily on many culture media, showing large
variation with the environment. It is aérobic and tolerates large
amounts of malic, citric and tartaric acids.

F. acuminatum E. & E. Sporodochia gregarious, minute, whitish
or flesh-colored; conidia falcate, attenate, 3 to 5 or 6-septate,
not constricted.

Described by Stewart *” as causing a girdling of potato stems in
New York.

F. roseum-lupini-alba Sacc.

Sporodochia pulvinate, minute, confluent, cinnabarine; co-
nidiophores variable, long, slender, branched, branches nodulose,
fusoid; conidia fusoid falcate, 45-55 x 4 yw, 4 to 6-septate. It
causes spots on leaves and pods of lupines and attacks the seeds,
inducing rot.

F. cucurbitariz Sacc. is on cucumbers in Queensland.

F. solani (Mart.) Sace.

Sporodochia globose, irregular, white; conidiophores branched; -
conidia fusoid-falcate, 3 to 5-septate, 40-60 x 7-8 u, subhyaline.

Clinton,®” also Wehmer ** and others, have shown this to be
the cause of “dry end rot” of stored potatoes. It may be iden-
tical with F. oxysporum.

F. pestis Sor. is given by Sorauer as the cause of “black-leg”

THE FUNGI WHICH CAUSE PLANT DISEASE 653

(see p. 46) of potatoes; it is perhaps identical with F. oxy-
sporum.

F. erubescens A. & v. Ov. produces small black sunken spots
on green and ripe toma-
toes in Germany ™ re-
sulting finally in mummi-
fication. Parasitism by
Ineans of enzymes was
demonstrated.

F. lycopersici Sace. 1°40?

Sporodochia as in F. oxy-
sporum; conidia falcate,
acute, 25-30 x 3.54 u,
hyaline to yellowish.

It is the cause of a to-
mato wilt or “sleeping
disease” resulting from in-
vasion of the ducts. Conidia of two kinds are produced, Fusa-
rium and Diplocladium. Infection is subterranean.

A nearly related disease differing chiefly in the fact that the
fungus does not reach far above ground has been described by
Smith.? The fungus in both cases is perhaps identical with
F. oxysporum.

‘F. lini Boll.“

Sporodochia erum-
pent, compact, cream
to flesh-colored; co-
nidiophores short,
much-branched; —_co-
nidia 3-septate, fusi-

form, slightly curved

Fia. 444.—F. lini, sketch, showing the mode of attack
upon a young root tip of a seedling flax plant. to falcate, 27-38 x
After Bolley. 3-3.5 Me

A serious widespread flax wilt is caused. The mycelium develops
luxuriantly from bits of diseased stem laid in sterile Petri dishes
and grows well in culture media. Normally a soil saprophyte, it
invades the roots, grows through the veins, plugs the ducts and
causes death. The sporodochia are found abundantly on the bases

Fia. 443.—F. lini. After Bolley.

654 THE FUNGI WHICH CAUSE PLANT DISEASE

of diseased plants. The spores abound on all diseased parts,
particularly on the seeds. Infection experiments have demon-
strated its pathogenicity.

F. tabacivorum Del. is said to cause a rot of tobacco in
France.

F. brassicz Thiim. is of economic importance on cabbage.*4

Inoculations of an undetermined species of Fusarium in pure
culture into soil also resulted in infection of 83% of the cabbage
plants grown therein.

F. decemcellulare Brick and F. theobrome Lutz. occur on
cacao.

F. ricini (Ber.) Bizz. is injurious to the castor oil plant.

F. incarnatum (Desm.) Sacc. is reported as the probable
cause of an aster wilt or blight in Europe. An undetermined
species is also reported on China aster by Galloway “ “” and
others.

A species of Fusarium on carnation leaves following in rust
sori was reported by Stewart “8 and a wilt disease or stem rot of
carnation was studied by Sturgis.“ He found the Fusarium in
the affected plants, it was isolated and inoculated into the soil
around the roots of carnations producing disease in several in-
stances.

F. pelargonii Crou. is described from geraniums.*”

F. dianthi P. & D.*!! on Dianthus cuttings, is a wound parasite,
following insect injury.

F. viole Wolf.

Infected areas dark, sunken; sporodochia within the host;
conidia fusiform-falcate, 28-38 x 4-6 yu, 3 to 5 times septate;
hyphe hyaline, 4~7 u in diameter, irregularly branched. It causes
a disease of roots and stems of pansy.

F. pini is believed to be the species responsible for a disease of
pine seedlings. *!?

F. blasticola Rost. causes death of conifer seedlings in Europe.

Tuberculariacez-Dematie-Amerospore (p. 638)

Hyphz olive to brown or black; conidia continuous, rarely
hyaline globose to elongate, sometimes unequal.

THE FUNGI WHICH CAUSE PLANT DISEASE 655

Key to Genera or Tuberculariacee-Dematia-Amerospore

Conidia not in chains
Sporodochia not setose
Conidiophores lacking
Lichenicolous....................
Not lichenicolous

Sporodochia gelatinous; conidia
globose, vesiculose..........

Sporodochia not gelatinous
Sporodochia hemispheric, with a
stratum of conidia........
Sporodochia disk-like, applan-

Conidiophores present
Sporodochia thick, tremelloid. . ....
Sporodochia not tremelloid
Conidiophores with a_ slender
apical appendage; conidia glo-
DOSE se ci ease eosigieel oa
Conidiophores not appendaged
Conidia globose
Sporodochia cellular, uniform
Sporodochia of three hyphal
layerse- nics ducer ees ness
Conidia ovoid to bacillar
Conidiophores bacillar; sporo-
dochia subdiscoid.......
Conidiophores branched
No brown radiate hyphe at
DASEL i dis Sut sida las ereeees
Brown radiate hyphe at

Sporodochia ciliate or with exserted hyphz

Sporodochia with loose exserted co-

nidiophores, verruciform. ........

Sporodochia margins with hairs or
setae

Sete dark... 0.0.0.0... cee eee

Seta or hairs white ..............

1. Spilomium.

2. Myriophysa.

3. Spermodermia.

4. Sclerodiscus.

5. Epidochium, p. 656.

6. Bonplandiella.

7. Epicoccum, p. 656.

8. Triplicaria.

9. Hymenopsis.

10. Strumella, p. 656.

11. Astrodochilum.

12. Trichostroma.

13. Chetostroma, p. 656.
14. Myrothecium.

656 THE FUNGI WHICH CAUSE PLANT DISEASE

Conidia in chains

Conidiophores lacking. ................ 15. Exosporina, p. 656.
Conidiophores present :
Sporodochia globose................ 16. Sphzromyces.
Sporodochia stellate. ..............-.. 17. Actinomma.

Epidochium Fries (p. 655)

Sporodochium thick, tremelloid, subglobose or wart-form, black
or pallid, erumpent; sporophores filiform, equal or apically swollen;
conidia ovoid, oblong or pyriform, solitary or catenulate.

Some fifteen species.

E. oryzez Miy. is found * on rice.

Epicoccum Link (p. 655)

Sporodochia globose or convex, cellular,
dark; conidiophores very short; conidia glo-
bose. Some fifty species.

E. hyolopes Miy. is on rice.

Strumella Saccardo (p. 655) iS

Sporodochia wart-shaped; conidiophores
Fic. 445.—Epicoccum, Pranched; conidia ovate, often somewhat bent.
After Saccardo. Some fifteen species.
S. sacchari Cke. is found on sugar cane.*!®

Chetostroma Corda (p. 655)

Sori dark or cushion-form black bordered with black hairs;
spores elliptical, fusiform or rarely almost spherical.

C. buxi Corda on Box =Nectria rousseliana. See p. 204.

C. cliviz Oud. causes blotches on Clivia.

Exosporina Oudemaus

Sporodochia erumpent; conidia catenulate, homomorphic,
continuous, greenish. Monotypic.
E. laricis Oud. is parasitic on larch leaves in Europe.

THE FUNGI WHICH CAUSE PLANT DISEASE 657

Tuberculariaciz-Dematiee-Phragmospore (p. 639)

Hyphz dark; conidia usually colored, 2 to several-septate, ob-
long to cylindric.

Key To Genera or Tuberculariacee-Dematie-Phragmospore.

Conidia in chains; sporodochium discoid. 1. Trimmatostroma, p. 657.
Conidia not in chains

Conidia 1-ciliate at each end......... 2. Ciliofusarium.
Conidia muticate
Sporodochium hairy............... 3. Excipularia.

Sporodochium smooth
Conidia laterally proliferate and

joined in bundles. .......... 4. Amallospora.
Conidia not proliferate and
united

Sporodochia convex-pulvinate.. 5. Exosporium, p. 658.
Sporodochia vertically cylindric
or clavate..............65 6. Listeromyces.

Trimmotostroma Corda

Sporodochia pulvinate, compact, bearing a layer of conidio-
phores; conidia oblong, often curved, 2 to 8-septate, catenulate
brown.

A genus of a half dozen species.

T. abietina Doh.*"4

Mycelium perennial; sporodochia foliicolus or caulicolus,
diffuse; conidiophores subhyaline, or tinged with olive-brown,
4.5 x 20-30 u, septate, sparsely branched, bearing the conidia
terminally; conidia catenulate, very variable, dark olivaceous-
brown, slightly roughened, usually oblong, spherical, straight or
inequilateral, continuous, spherical, 5 u, or 2 to 5-celled and 5-6
x 8-16 yp, not constricted, rarely muriform, 5 x 10 p.

On white and balsam firs in Canada. The perennial habit of
the mycelium makes the pest a persistent one and as no conidia
are produced till the second year after infection its presence is
the more readily overlooked.

658 THE FUNGI WHICH CAUSE PLANT DISEASE

Exposorium Link (p. 657)

Sporodochia convex, compact; conidiophores dark, simple,
densely compacted; conidia single, oblong to cylindric, plurisep-
tate.

Some twenty-five species.

In part =Coleroa and Coryneum. See pp. 227, 236.

E. juniperinum (E.) Jacz. =Coryneum juniperinum. See p. 236.

E. laricinum Mas. is found on living larch twigs.

E. tiliz Lk. grows on young shoots of Tilia.

E. palmivorum Sacc.*%

WiGKy .
LOY,

=
AUT

sy
Es

ea SIT Ha oo

eSSSALe

re Qlereye
oy,

ef eS
ATE
am
Pa ae © etek

ES Sane

Fic. 446.—E. palmivorum. 3, a sporodochium,
5, spores. After Trelease,

Spots amphigenous, minute, suborbicular, 1-3 mm. in diameter,
brown, scattered; sporodochia superficial, densely gregarious,
punctiform, black; 30 x 60-80 u; conidiophores oblong, con-
tinuous, reddish olive, 5-6 x 14-16 yu, conidia borne singly,
fusoid, straight or curved, apically obtuse or acute, basally obtuse,
8 to 10-septate, not constricted, olive-brown, ends paler, 8-9 x
80-90 py.

On palms, especially species of Phoenix in America.

E. presii Bub. on species of Phoenix in Europe is very similar
to the preceding species.

In the Tuberculariacese-Dematiex-Dictyospore Thyrococcum
sirakofi Bubak forms black tubercles under bark of mulberry
and kills the twigs.**

THE FUNGI WHICH CAUSE PLANT DISEASE 659

Mycelia-Sterilia (p. 479)

Numerous forms are known merely as sterile mycelia. They
may or may not make sclerotia. In several instances these sterile
forms are so aggressive as to warrant classing them among the
worst of plant pathogens. Until more is known of them it becomes
necessary to arrange and name them, for convenience of reference,
in a purely artificial manner.

Key To rorm Genera or Mycelia-Sterilia.

Tubercle-like
Tubercles connected with fibrils........ 1. Rhizoctonia, p. 659.
Tubercles without fibrils
Cortex discrete.............000 cece 2. Acinula.
Cortex not discrete... ............4.. 3. Sclerotium, p. 660.
Maculiform
Black stromata in leaves and stems..... 4. Ectostroma.
Pseudo stromata in cortex............. 5. Phellomyces.
Root-like
Filaments rigid, broad, terete or depressed,
dark, white within................ 6. Rhizomorpha.
Filaments rigid, capilliform, dark, closely
adhering. ........... 00: e eee eens 7. Capillaria.
Clavariform; filaments terete, vertical, sim-
ple or branched..................055 8. Anthina.
Cobwebby or byssoid
Cespitose interwoven, primary hyphe
joined in bundles. ...............: 9. Ozonium, p. 661.
Cespitose interwoven, hyphe not fascicu-
late; blacks o<.s6s-sea seta die cacnsie os 10. Rhacodium.

Cobwebby, soft, evanescent, white or pale 11. Hypha.
Adpressed, creeping, dendritic, white to

brownish, not forming a continuous

membrane. .......---+ esses eeeees 12. Himantia.

Membrane-like; densely interwoven, form-
ing a continuous suberose or coriaceous
membrane. ............0seeeeeeeees

Rhizoctonia De Candolle

Sclerotia variable in form, horny-fleshy; cortex thin, mem-

13. Xylostroma, p. 663.

660 THE FUNGI WHICH CAUSE PLANT DISEASE

branous, persistent, inseparable; formed among and connected by
the mycelial threads.

There are about a dozen so-called species, some of them very
important plant pathogens. See pp. 407, 408.

R. betz Kiihn and R. solani Kiihn =Corticium vagum solani,
as does also part of what has been referred to as R. violacez.

R. medicaginis D. C. (Tul.);” (see also %* 416417).

Hyphe subtomentose, on the cambium of the host, forming a
membrane or fasciculate strands, covering the host in time with a
violet coating; sclerotia reddish-violet.

On alfalfa in Europe and America."

Duggar who has studied this form and the form allied to Corti-
cium (pp. 407, 408) regards the two as distinct though Gtissow 4”
who has also studied both pronounces them thesame. Duggarsays,
“The fungus appears upon the root as a close weft of violet-colored
hyphz composed of cells more or less uniform in diameter. Mor-
phologically it bears no resemblance to the sterile stage of Cor-
ticlum.”” This form is found on alfalfa, asparagus, beet, and-pos-
sibly other plants. ;

Leptospheria has been reported as its ascigerous stage though
the evidence of such connection is not conclusive.

R. crocorum D. C. is a form which kills the corms of saffron.

R. strobi Scholz is the name given to a form described as seriously
injuring young pine trees in Austria.*??

R. subepigea Ber. is destructive on the roots of coffee.*?*

A Rhizoctonia of undetermined species has been found on buck-
wheat in the United States.424

Sclerotium Tode (p. 659)

Sclerotia roundish or irregular in form, cartilaginous-fleshy, not
connected by mycelial threads; cortex thin, membranous, in-
separable.

Over 200 species have been described.

S. rolfsii Sacc.?% 42 438

Sclerotia small, brown, about the size of a mustard seed.

This sterile fungus possesses a very aggressive mycelium which
under favorable conditions of moisture grows on almost anything
living or dead, producing a dense white cotton-like mass of threads.

THE FUNGI WHICH CAUSE PLANT DISEASE 661

Soon the sclerotia form as mustard-seed-like bodies. They are
produced in great abundance on all media but neither these struc-
tures nor the mycelium have yet been seen to bear spores of any
kind. The fungus was first studied by Halsted 2! and later by
many others. It was described and named by Saccardo from speci-
Mens communicated by Stevens.

S. cepivorum Berk.

Minute, spherical, gregarious, black. It is found on various
species of Allium, causing rot.

Fic. 447.—S. rolfsii, sclerotia. After Halsted.

S. rhizoides Auer.**

Subglobose, at first white-villose, then smooth, black, rugose.

On Calamagrostis and other grasses. It causes considerable
injury to the hay crop in Europe.

S. tuliparum Klebahn,*”’ S. tulipe Lib. and S. bulborum Wak.
are found on tulips, and other bulbs. A relation to Sclerotinia is
usually assumed but has not been demonstrated. See p. 136.

S. oryze Catt. is found on rice in Japan and Italy.

Ozonium Link. (p. 659)

Cobwebby or byssoid, cespitose, hyphe densely interwoven,
primary hyphe fasciculate.
Some twelve species.

662 THE FUNGI WHICH CAUSE PLANT DISEASE

O. omnivorum Sh. 48433

Mycelium dirty yellow; sometimes whitish when young, grow-
ing in the vascular bundles of the host; hyphe forming strands
and spreading from them, producing a rather dense arachnoid
layer on the surface of the host and bearing 1 to 4 branches arising

Fic. 448.—S. rolfsii, sterile mycelium growing on carrot. After Stevens and Hall.

and growing at right angles from the same point near the ends,
3 to 5 win diameter, tapering toward the ends..

It causes root rot on almost any kind of plant including among
its hosts a large variety of trees. The first description was by
Pammel in a Texas Bulletin; a later one was by Shear. The fungus
destroys the smaller rootlets, cortex of older roots and invades the
vascular system and medullary rays, resulting in wilt and death.
It may be seen as dirty yellowish strands or as a thin weft
superficially. Sclerotia-like bodies appear on the roots often at

THE FUNGI WHICH CAUSE PLANT DISEASE 663

lenticels. Inside of the host tissue the mycelium is not typically
associated to form strands and its cells are hyaline.

The fungus was in early studies difficult to isolate but Atkinson
in 1893 *” obtained pure cultures by rinsing the diseased roots in
distilled water, cutting in small pieces and placing on sterile filter
paper lying on sterile sand in a moist chamber. In a few days the
strands grew over the paper onto sterilized slides. Bits of sterilized
cotton-root were then placed in contact with the advancing hyphe.
Soon the new culture thus secured could be transferred at will.
A slight acidity retards bacterial growth and renders isolation of
the Ozonium less difficult. In culture sclerotia about 3 mm. in
diameter, whitish and woolly, later brown, appear.

Xylostroma Tode (p. 659)

This occurs, forming thick, felt-like layers, in cracks of timber.
It is regarded as the mycelium of various Hymenomycetes, es-
pecially Fomes.

Fungi of Unknown Affinity

The following imperfectly known genera do not fit readily into
the scheme of classification and are all in need of careful study.

Acrocystis Ellis & Halsted

Monotypic; though technically a nomen nudem, the illustrations
are recognizable. Examination of the original material shows
Saccardo’s reference to the Mucorales to be untenable.

A. batate E. & H.*4

Hyphe intercellular, branched, producing enlarged cysts at the
ends of branches, the nature of these unknown; enlarged, intra-
mycelial swellings contain numerous rounded conidia.

It is described as the cause of soil rot of sweet potatoes.

Graphiola Poit

Mycelium within the host; fruiting body rotund, carbonous
duplex, the outer layer of interwoven branched hyphe, firm, in-

664 THE FUNGI WHICH CAUSE PLANT DISEASE

terior softer, of fertile and sterile fasciculate hyphe; fertile hyphe
with short branches bearing the spore-mother-cells which divide
into two globose or angular spores; germination by a filiform
conidia-bearing mycelium.

A genus of seven species, chiefly on palms.

G. pheenicis (Moug.) Poit.** 4°

Sprodochium 1-1.5 x 500 yu; exoperidium horny, black, inner
peridium membranous, hyaline; spore-mass yellow; spores globose
or elliptic, 3-6 y, with a thick, smooth, hyaline wall.

On the date and other palms throughout the world.

THE FUNGI WHICH CAUSE PLANT DISEASE 665

Fig. 449.—G. phenicis. II, sporiferous organ.
III, section of the same. After Stone and Smith.

BIBLIOGRAPHY OF FUNGI IMPERFECTI*

1Stevens, F. L. and Hall, J. G., Bot. Gaz. 48: 1, 1909.

? Leininger, H., C. Bak. 29: 4, 1911.

3 Cobb, N. A., D. Agr. New So. Wales, Miss. Pub. 666: 21.
‘ Hedgcock, G., Myc. 10: 2, 1904.

5 Kirk, T. W., N. Z. R. 348, 1906.

6 Potebnia, A., Ann. Myc. 8: 58, 1910.

7Scott, W. M. and Rorer, J. B., B. P. I. B. 144: 1909.

® Scott, W. M. and Quaintance, A. C., F. B. 283: 14, 1907.
® Clinton, G. P., Ill. B. 69: 1902.

10 Stewart, F. C., N. Y. (Geneva) R. 14: 545, 1895.

11 Scott, W. M. and Rorer, J. B., B. P. I. B. 121: 1908.

12 Stevens, F. L., N. C. B. 196: 54, 1907.

13 Ann. Inst. Cent. Amp. Roy. Hong. 3: 167, 1905.
“Selby, A. D., O. B. 214: 445, 1910.

16 Briesig, Bul. Min. Ag. Ind. & Cen. Rome, 1910.

6 Miyaki, Bot. Mag. Tokyo 23: 1909.

v Stewart, F. C., N. Y. (Geneva) B. 328: 1911.

18 Halsted, B. D., N. J. R. 12: 279, 1891.

19 Idem. 19, 11: See 1890.

*” Halsted, B. D., N. J. B. 70: 9, 1890.
21 Halsted, B. D., N. J. R. 14: 355, 1803.
2 Selby, A. D., 0. B. 105: 222, 199.

23 Patterson and Charles, B. P. I. B. 171.

4 Diedicke, H., C. Bak. 19: 168, 1907.

5 Halsted, B. D., N. J. R. 13: 297, 1892; R. 12: 1891.
*N, J. R. 15: 331, 1894.

7 Humphrey, J. E., Mass. R. 10: 231, 1892.

*® Humphrey, J. E., Zeit. 3: 360, 1893.

2° Gueguin, B., 8. M. Fr. 18: 312, 1902.

8 Aderhold. R., C. Bak. 6: 620, 1900.

*t Trinchieri, R., Bul. Ort. Bot. R. Univ. Napoli 2: 409, 1909.
2U. 8. D. Agr. R. 88.

* Stewart, F. C., (Geneva) R. 15: 456, 1896.

*See footnote, page 53.
666

BIBLIOGRAPHY OF FUNGI IMPERFECTI 667

34U. 8. Dept. Agr. R. 87.

35 Chester, F. D., Del. R. 5: 75, 1892.

% Selby, A. D., O. B. 92: 233, 1898.

37 Lewis, C. E., Sc. 31: 752, 1910.

38 Lewis, C. E., Me. B. 170: 1909.

%° Halsted, B. D., N. J. B. 91: 1892.

*© McAlpine, Dept. Agric. Melbourne, 132, 1899.

“1 McAlpine: Fungi of the Vine in Australia.

4 Frank, Zeit. 3: 28, 1893.

‘3 Prillieux and Delacroix, B. S. My. Fr. 6: 178, 1890.
“4 Rostrup, E., Zeit. 4: 195, 1894.

45 Manns, T. F., Sc. 32: 726, 1910.

“6 Manns, T. F., Mycologia 1: 28, 1911.

4 Bos. Zeit. 16: 257, 1906.

* Quanjer, Zeit. 17: 259, 1907.

“ Rostrup, E., Zeit. 4: 322, 1894.

50 Rostrup, E., Tid. f. Landok. R. 5: 11, 330, 1891.

51 Kirk, T. W., New Zealand, D. Ag. R. 13: 410, 1905.
52 Klebahn, H., Zeit. 20: 1, 1910.

53 Fron, G., Bull. Trim. Soc. Myc. France 25: 66.

54 Halsted, B. D., N. J. B. 76: 25, 1890.

55 Stewart, F. C., N. Y. (Geneva) B. 179, 1900.

5s Arthur, J. C., N. Y., (Geneva) R. 3: 383, 1884.

57 Deidicke, H., Ann. Mye. 9: 8, 1911.

58 Steward, F. C., Rolfs, F. M., and Hall, F. H., N. Y. B. 191: 298, 1900.
59 Cordley, A. B., Ore. Bul. 60: 1900.

60 Paddock, W., N. Y. (Geneva) B. 163: 203, 1899.

61 Eriksson, Zeit. 1: 29, 1891.

62 Halsted, B. D. and Fairchild, D. G., J. Myc. 7: 1891.
63 Allescher, A., Zeit. 5: 276, 1895.

6 Reed, H. 8., Mo. B. 69: 1905.

6 Linhart, Zeit. 5: 92, 1895.

« Stoneman, B., Bot. Gaz. 26: 1898.

«7 Thaxter, R., Ct. R. 13: 163, 1889.

«8: Ducomet, Ann. l’ecole Nat. d’Agr. d. Rennes 24, 1909.
* Agr. Soc. 8: 292, 1894.

% Williams, T. A., S. Dak. B. 29: 1891.

™1 Miyake, I., Phytopath. Inst. Agrikult. Abt. der Univ. Tokyo, 1909.
72 Bubak, F., Zeit. Land. Ver. Oe. 18: 502, 1910.

73 Chester, F. D., Del. R. 40, 1902.

74 Edgerton, C. W. La. B. 126: 194.

668 THE FUNGI WHICH CAUSE PLANT DISEASE

75 Scott, W. M. and Rorer, J. B., B. P. I. B. 121: Dt. 5, 1908.

% Chester, F. D., B. Torr. Bot. Club, 18: 373.

7 Paddock, W., N. Y. (Geneva) B. 185: 1900.

78 Peck, C. H., R. N. Y. Mus. Nat. Hist. 1881.

7 Atwood, Proc. A. A. A. 8. 47: 413, 1898.

% Clinton, G. P., Ill. B. 69: 192, 1902.

% Paddock, W., Science 8: 596.

82 Shear, C. L., Se. 31: 748, 1910.

83 Mangin, L., Jour. d’Agric. Pratique, 1901.

#4 Griffon and Maublanc, B. 8. Mye. Fr. 26: 3.

8 Gilssow, H. T., Zeit. 20: 406; 1909 also Jour. Roy. Hort. Soc. (Lon-
don) 222, 1908.

%® B.S. My. Fr. 11: 75, 1895.

87 Stewart, F. C. and Eustace, H. J., N. Y. (Geneva) B. 226: 1902.

% Stevens, F. L. and Hall, J. G., N. C. B. 196: 1907.

® O’Gara, P. J., Phyto. 1: 100, 1911.

% Viali and Ravez, Rev. d. Vit. 197, 1895.

%1 Van Hook, J. M., O. B. 173: 1906.

° Kriiger, F., C. Bak. 1: 620, 1895.

3 Bolthauser-Aurisweil, H., Zeit. 1: 135, 1891.

4 Porto Rico, R. 397, 1904.

% Clinton, G. P., Ct. R. 326, 1903.

% Bolthauser, H., Zeit. 8: 263, 1898.

% Dudley, W. R., N. Y. (Cornell) B. 14: 182, 1889.

% Stevens, F. L., Bot. Gaz. 44: 241, 1907.

*® Stewart, F. C., French, G. T. and Wilson, J. K., N. Y. (Geneva) B.
305: 395, 1908.

10 Laubert, R., Arb. K. Gesund. Biol. Abt. 3: 441.

101 McAlpine D., Melbourne Dept. of Agric. 132, 1899.

102 Pyillieux and Delacroix, B. S. My. Fr. 9: 275, 1893.

103 Burrill, T. J. and Barrett, J. T., Ill. B. 133: 1909.

104 Barrett, J. T., Sc. 27: 212, 1908.

105 Stevens, F. L. and Hall. J. G., N. C. R. 31: 38, 1909.

106 Smith, E. F. and Hedges, F., Sc. 30: 60, 1909.

107 Howard, A., Ann. Bot. 15: 683, 1901.

18 Pole, J. B. Evans, Trans. D. Agr. Soc. B. 4: 1910.

1 Butler, E. J., Pusa Agr. Reas. B. 9: 1908.

110 Clendenin, I., Bot. Gaz. 21: 92, 1896.

111 Minch E. and Tubeuf, C., Nat. Zeit. f. For. u. Land. 8: 39, 1910.

112 Cavara, F., Zeit. 4: 109, 1894.

13 Pammel, L. H., Ia. B. 13: 67, 1891.

BIBLIOGRAPHY OF FUNGI IMPERFECTI

14 Agr, Jour. 9: 185, 1896.

116 Taft, L. R., Mich. Bul. 83: 1892.

us Cavara, F., Zeit. 3: 23, 1893.

117 Mangin, L., E. 8. R. 10: 452, 1898.

18 B. Soc. Myc. Fr. 15: 108.

u° Humphrey, J. E., Mass. R. 7: 1889.

120 Patouillard and Lagerheim, B.S. My. Fr. 136, 1892.
121 McCarthy, G., N. C. B. 98: 151, 1894.

122 Chester, F. D., Bull. Torr. Bot. Cl. 372, 1891.

123 N. Y. (Geneva) B. 61: 137, 1893.

124 Duggar, B. M., N. Y. (Cornell) B. 132: 256, 1897.
125 Humphrey, J. E., Mass. R. 281, 1891.

128 Rogers, S. 8., Cal. B. 208: 1911.

127 Halsted, B. D. N. J. R. 95, 294.

128 Selby, A. D., O. B. 73: 1896.

129 Chittenden, F. J., Jour. Hort. Soc. London 35: 216.
130 Beach, 8. A., N. Y. (Geneva) R. 11: 557, 1893.

131 Salmon, R., Econ. Myc. 1908.

132 Stewart, F. C., N. Y. (Geneva) R. 455, 1896.

133 Spaulding, P., B. P. I. Cir. 35: 1909.

134 Jaczewski, A., Zeit. 10: 340, 1900.

135 Alall, C. J. J. von, Ann. Mye. 1: 508, 1903.

136 Sturgis, W. C., Conn. State R. 21.

137 Selby, A. D., Ohio B. 79: 1897.

18 Kirk, T. W., N. Z. D. Agr. 157, 1907.

18 Stone, G. E., and Smith, R. E., Mass. R. 67, 1897.
140 Delacroix, G., B. 8. My. Fr. 19: 353, 1903.

141 Scribner, F. L., Tenn. B. 4: 1891.

142 Pierce, N. B., V. P. P. B. 2: 170, 1892.

43 Viala & Pacottet, Rev. de Vit. 1904.

44 Grossenbacher, J. G., N. Y. (Geneva) T. B. 9: 1909.
145 Brizi, U., Zeit. 6: 65, 1896.

140 Paddock, W., N. Y. (Geneva) B. 124, 1897.

‘7 Burrill, T. J., Agr. Rev. Wash. 97: 1882.

448 Lawrence, W. H., Wash. Bul. 97: 1910.
_14# Rorer, J. B., Rep. of the Mycologist, Trinidad, 1910.
160 Cardin, P. P., Cuba Rev. 8: 28.

161 Wehmer, B., Zeit. 11: 193, 1901.

152 Kirchner, O., Zeit. 12: 10, 1902.

163 Linhart, G., Zeit. 12: 281, 1902.

164 Fulton, H. R., Se. 752, 1910.

669

670 THE FUNGI WHICH CAUSE PLANT DISEASE

165 Chester, F. D., Del. R. 4:60, 1891.

iss Edgerton, C. W., Bot. Gaz. 45: 403, 1908.

157 Sorauer, Zeit. 7: 255, 1897.

168 Laubert, R., Zeit. 14: 257, 1904.

19 Stone, G. E. and Smith, R. E., Mass. R. 10: 69, 1898.

160 Stewart, F. C., N. Y. (Geneva) R. 14: 531, 1895.

161 Edgerton, C. W., Ann. Myc. 6: 1908.

162 Massee, G., Kew. Bull. 269, 1908.

163 Commes, Mit d. Kais. Welt. Inst. f. Land., Bramberg, 2: 1910.
164 Whetzel, H. H., N. Y. (Cornell) B. 239: 1906.

168 Whetzel, H. H., N. Y. (Cornell) B. 255: 1908.

16 Bull. Torr. Bot. Cl. 20: 246, 1893.

187 Harvey, F. L., Me. R. 152, 1893.

18 Bull. Soc. Myc. D. Fr. 10: 162, 1894.

19 Stevens, F. L. and Hall, J. G., Zeit. 19: 65, 1907.

10 Hume, H. H., Fla. B. 53: 171, 1900.
171 Rolfs, P. H., B. P. I. B. 52: 1904.
172 Hume, H. H., Fla. B., 74: 1904.
13 Smith, R. E., Cal. Cult. 1911.

174 Edgerton, C. W., Sc. 31: 717, 1910.
178 Lewton-Brain, L., Hawaii Sugar Planters Assn. Bul. 8: 1908.
178 Stevens, F..L., N. C. R. 83: 71, 1911.

17 Selby, A. D. and Manns, T. F., O. B. 203: 187, 1909.

178 Bain, S. M. and Essay, 8. H., Tenn. B. 75: 1906.

19 Bain, S. M. and Essay, S. H., J. Myc. 12: 192, 1906.

189 Bain, S. M. & Essay, S. H. Sc. 22: 503, 1905.

181 Barre, H. W., S. C. B. 153: 1910.

182 Southworth, E. A., J. Myc. 6: 46, 1890.

183 Hedgcock, G. G., Mo. Bot. Gard. R. 153, 1905.

184 Stone, G. E. and Smith, R. E., Mass. R. 11: 152, 1898.

185 Smith, R. E., Bot. Gaz. 27: 203, 1899.

1 Stewart, F. C., N. Y. (Geneva) B. 179: 105, 1900.

487 Noack, F., Zeit. 11: 202, 1901.

188 Halsted, B. D., N. J. R. 17: 410, 1896.

189 Noack, F., Zeit. 9: 4, 1899.

10 Atkinson, G. F., N. Y. (Cornell) B. 61: 302, 1893.

1 Southworth, E. G., J. Myc. 6: 171, 1891. *

192 Edgerton, C. W., La. B. 120: 1910.

13 Jones, L. R., and Giddings, N. J., Vt. R. 19: 235, 1907.

194 Raciborski, Zeit. 8: 66, 1899.

6 Vuillemin, P., B. Sc. M. Fr. 12: 33, 1896.

BIBLIOGRAPHY OF FUNGI IMPERFECTI 671

16 Reed and Cooley, A., Va. 115, 1909-10.

197 Shear, C. L., B. P. I. B. 110: 1907.

18 Wolf, F. A., Neb. R. 21: 69, 1908.

199 Pierce, N. B., V. P. P. B. 20: 1900.

200 Wagner, F. and Sorauer, P., Zeit. 8: 256, 1898.

201 Jaczewski A., Zeit. 11: 203, 1901.

202 Smith, ‘R. E., ef al, Cal. B. 191: 73, 1906.

23 Lewis, C. E., Se. 31: 752, 1910.

24 Butler, E. J., India D. Agr. 2: 8, 1909.

205 Stewart, F. C. and Eustace, H. J., N. Y. (Geneva) R. 20: 146, 1902.
26 Pammel, L. H., Ia. B. 13: 61, 1891.

207 Fairchild, D. G., J. Myc. 7: 249, 1893.

28 Arthur, J. C., N. Y. (Geneva) R. 6: 347, 1887.

29 Geneva R. 8: 293.

210 Pammel, L. H., Ia. B. 15: 62, 1891.

211 Brooks, C., Bull. Torr. Bot. Cl. 35: 423, 1908.

212 Brooks, C., N. H. B. 144: 116, 1909.

213 Constantin, Rev. Gen. d. Bot. 6: 289, 1894.

214 Massee, G., Gard. Chron. July 23, 1898.

2165 Qudemans, C. R. Acad. Roy. Sc. d. Pays.-Bas. Jan. 1897.
216 Sturgis, W. C., Ct. (New Haven) R. 20: 263, 1896.
217 Thaxter, R., Ct. R. 81, 1890.

218 Frank, Ber. d. Bot. Ges. 16: 280.

219 Sturgis, W. C., Ct. State. Sta R. 20: 266, 1896. °

2% Arthur, J. C., Ind. B. 65: 1897.

221 Arthur, J. C., Ind. B. 39, 1892.

222 Sturgis, W.C., R., Ct. R. 15: 153, 1891.

223 W. Va. B. 2: 1897.

224 Duggar, B. M., N. Y. Cornell B. 163: 359, 1899.

226 Griffon and Maublane, B., S. M. d. Fr. 26: 132, 1910.
228 Magnus, P., Ver. d. Gas. lux Natur freunde.

227 Brizi, U., Ric. Lab. Chem. Agr. Sc. Milano 3: 169.

228 Thom, C., B. B. Animal Industry.

229 Heald, F. D., Neb. D. 103: 1907.

230 Stewart, F. C. and Hodgkiss, H. E., N. Y. (Geneva) T. B. 7: 1908.
231 Smith, R. E., Bot. Gaz. 29: 395, 1900.

222 Brizi, U., C. Bak. 3: 141, 1897.

233 Ward, H. M., Ann. Bot. 2: 319, 1888.

234 Istvanffh, G., Ann. L’Inst. Cent. Amp. Roy. Hong. 1905.
235 Kean, A. L., Bot. Gaz. 16: 8, 1890.

238 Wehmer, C., Zeit. 4: 204, 1894.

672 THE FUNGI WHICH CAUSE PLANT DISEASE

231 Humphrey, J. E., Mass. R. 1892: 219.

238 Jones, L. R., Vt. R. 5: 141, 1892.

239 Bailey, L. H., N. Y. (Cornell) B. 96: 387, 1895.
240 Stone, G. E. and Smith, R. E., Mass. B. 69: 1900.
241 Brooks, F. T., Ann. Bot. 22: 479, 1908.

242 Kissling, Hedwegia 28: 227, 1889.

243 Reidemeister, Ann. Myc. 7: 19, 1909.

44 Wulff, T., Ark. Bot. 8: 18, 1909.

246 Bos. J. R., Zeit. 8: 263, 1898.

246 Bureau Plant Industry, B. 171.

247 Fawcett, H. S. and Burger, O. F., Mycologia 3: 151, 1911.
248 Behrens, J., Zeit. 3: 89, 1893.

20 C, Bak. 6: 625, 1900.

20 Clinton, G. P., Ct. R. 1905: 274.

‘251 Salmon, Econ. Mycol. 1909: 98.

252 Briosi, G. and Farneti, R., Atti. Inst. Bot. Univ. Pavia 8: 4.
253 McAlpine, Fungus Diseases Citrus, Austral, 77.
254 Delacroix, G., B. 8. M. Fr. 19: 128.

255 Fawcett, G. L., P. Rico R. 1909: 35, 1910.

266 Van Hook, J. M., N. Y. (Cornell) B. 219: 1904.
257 Rankin, W. H., Spec. Crops, N.S. 9: 349, 1910.
268 Gueguen, F., Bul. Tri. Soc. Myc. France, 22: 254.
259 Gueguen, F., C. R. Soc. Biol. Paris 68: 221.

20 Craig, J. and v. Hook, J. M., N. Y. (Cornell) B. 207: 199, 1902.
61 Kustace, H. J., N. Y. (Geneva) B. 227: 367, 1902.
262 Aderhold, R., C. Bak. 5: 552, 1899.

263 Twaroff, K. S., Zeit. 14: 36, 1904.

264 Patterson, F. W., Sc. 31: 756, 1910.

25 Constantine, J. A. Dufour, L., Zeit. 3: 310, 1893.
#6 Atkinson, G. F., Bot. Gaz. 15: 166, 1890.

27 Atkinson, G. F., O. E. S. B. 33: 309, 1896.

268 Thaxter, R., Ct. R. 14: 98, 1890.

© Porto Rico R. 1903: 449.

270 Chittenden, F. J., Gard. Chron. 3: 277.

211 Metcalf, H., S. C. B. 121: 1906.

272 Fulton, H. R., La. B. 106: 1908.

73 Metcalf, H., Sci. 25: 264, 1907.

74 Smith, E. F., J. Myce. 7: 91, 1892.

778 Magnus, P., Ber. d. deut. Bot. Ges. 28: 26, 1910.
26 Zeit. 5: 335.

7 Petch, T., Circ. Roy. Bot. Gard. Ceylon, Nov. 1909.

BIBLIOGRAPHY OF FUNGI IMPERFECTI 673

278 Petri, L., Mo. Gior, Bot. Ital. 582, 1803.

27? Porto Rico R. 398, 1904.

28 Cavara, F., Zeit. 3: 24, 1893. ;

81 Smith, R. E. and Butler, O., Cal. B. 200: 1908.

2 Fawcett, H.S., Fla. R. 46: 1909.

783 Swingle, W. T. and Webber, H. J., V. P. P. B. 8: 1896.
2 Cal. R. 297, 1892-3.

28 Aderhold, R., Zeit. 6: 72, 1896. '

28 Arthur, J. C., Ind. B. 19: 8, 1889.

287 Penzig, Studi Bot. Lugli Agrumi, 1887.

* Scribner, F. L., Torr. Bull. 13: 181, 1886.

2 Fawcett, Fla. R. 42, 1909.

~ Fawcett, Fla. R. 46, 1907.

21 Fawcett, Mycologia, 2: 245, 1910.

202 Chester, F. D., Del. R. 8: 60, 1895.

3 Pammel, L. H., Ia. B. 23: 919, 1898.

2 Sturgis, W. C., Ct. R. 20: 269, 1896.

28 Johnson, E. C., Sc. 31: 792, 1910.

2% Johnson, E. C., Phytopy. 1: 1911.

27 Farraris, T., Ann. Myc. 7: 283, 1909.

28 Orton, W. A., Sc. 21: 508, 1905.

29 Trelease, W., D. Agr. R. 129, 1886.

30 Prillieux and Delacroix, B. S. M. Fr. 7: 218.

#01 Butler, O., Ann. Bot. 25: 130, 1911.

302 Aderhold, R., Arb. d. biol. Abt. f. land. i for. Gesund II, 519, 1902.
303 Kirchner, O., Zeit. 2: 324, 1892.

304 Sorauer, P., Zeit. 8: 283, 1898.

306 Bos. J. R., Zeit. 13: 87, 1903.

36 Reed, H. S. and Cooley, J. S., Va. R. 78, 1911.

307 Pammel, L. H., King, C. M. and Bakke, A. L., Ia. B. 116: 1910.
38 Harvey, F. L., Me. R. 95, 1894.

a9 Thaxter, R., Ct. R. 1889.

310 Johnson, T., Econ. Proc. Roy. Dublin Soc. 1: 345, 1907.
311 Appel and Laubert, Ber. d. deut. Bot. Ges. 23: 218, 1905.
312 Clinton, G. P., Ct. State R. 357, 1907.

313 Aderhold, Zeit. 6: 72, 1896.

314 Aderhold, R., Arb. K. Ges. Biol. Ab. 3: 439.

315 Jensen, C. N. and Stewart, V. B., Phyto. 7: 120, 1911.
316 Patterson, F. W., Torrey Bull. 37: 205, 1910.

317 Thaxter, R., Ct. R. 13: 158, 1889.

318 Miyake, Ann. Bot. 3: 1889.

674 THE FUNGI WHICH CAUSE PLANT DISEASE

219 Sturgis, W. C., Ct. R. 20: 276, 1896.

32 Collinge, W. E., R. I. Econ. Biol. Birmingham.

321 Walkoff, K., Zeit. 12: 283, 1902.

322 Atkinson, G. F., Bot. Gaz. 16: 62, 1891.

323 Griffin, H. H., Col. B. 62: 1901.

34 Ga. R., 351, 1900.

328 New South Wales Dept. Agric. Rept. 1893.

326 Harter, L. L., Mycologia 3: 154.

327 Sturgis, W. C., Ct. R. 19: 186, 1895.

328 Behrens, J., Zeit. 2: 327, 1892.

32 Dorsett, P. H., V. P. P. B. 23: 1900.

390 Halsted, B. D., N. J. B. 76: 1890.

331 Stevens, F. L. and Hall, J. G., Bot. Gaz. 47: 409, 1909.
332 Rolfs, P. H., Fla. B. 47: 124, 1898.

333 Jones, L. R., Vt. B. 72: 16, 1899.

334 Jones, L. R. Vt. R. 10: 45, 1896.

335 Jones, L. R. Vt. R. 9: 79.

436 Galloway, B. T., Agric. Science 7: 377, 1893.

337 Brocq-Rousseau, D., B. Soc. Nat. Agr. France, 67: 271.
338 Jones, L. R., and Grant, Bull. Tor. Bot. Club, 24: 257, 1897.
3% Barre, H. W., S. C. B. 153: 1910.

30 Fawcett, H.S., Fla. B. 106: 1911.

341 Beach, S. A., N. Y. (Geneva) B. 125: 1897.

42 Bioletti, F. T., Cal. R. 235, 1895.

343 Pierce, N. B., Myc. 7: 66, 232, 1892.

344 Earle, F.S., Div. Pom. B. 5: 27, 1897.

345 Jones, L. R. and Morse, W. T., Vt. R. 18: 271, 1905.
346 Bubak, F., Ber. d. deut. Bot. Gez. 28: 533, 1910.

47 Lagerheim, G. and Wagner, G., Handloch Tid. 426, 1903.
+ Sturgis, W. C., Ct. R. 20: 273, 1896.

3 Tyron, H., Rept. Dept. Agric. and Stock. Queensland 89: 1907.
360 Atkinson, G. F., N. Y. (Cornell) B. 49: 314, 1892.

851 Scribner, F. L., U.S. D. Agr. R. 117, 1886.

352 Duggar, B. M., N. Y. (Cornell) B. 163: 352, 1899.

363 Selby, A. D., O. B. 105: 232, 1899.

464 Raciborski, M., Zeit. 8: 66, 1898.

465 Chester, F. D., Del. R. 95, 1889.

366 Fairchild, D. G., U.S. D. Ag. R. 429, 1889.

387 Halsted, B. D., N. J. R. 397, 1896.

358 Atkinson, G. F., Am. Flor. 8: 723, 1893.

359 Zimmermann, A., C. Bak. 8: 221, 1902.

BIBLIOGRAPHY OF FUNGI IMPERFECTI 675

#0 McAlpine, D., J. Dept. Agr. Victoria, 801, 1902.

381 Edgerton, C. W., Phytop. 1: 12, 1911.

382 Marchal, E., Bul. Agr. Brussels 17: 4.

303 Zimmerman, A., C. Bak. 7: 145, 1901.

364 Massee, G., Kew Bul. 19, 1898.

366 Sheldon, J. L., Torreya 8: 141, 1908.

36 South, F. W., W. Ind. B. 11: 83, 1911.

887 Stevens, F. L., and Hall, J. G., J. Myc. 13: 94, 1907.

388 Appel and Wallenweber, Arb. d. Kais. Biol. Ans. f. Land. u. Frst. 8:
Heft 1.

39 Cook, M. T., Se. 31: 751, 1910.

37 Aderhold, Zeit. 11: 65, 1901.

371 Aderhold, R., C. Bak. 5: 523, 1899.

372 Pound and Clements, Neb. Bot. Sur. 3: 12, 1893.

373 Cook, M. T., Del. Bull. 93: 1911.

374 Osterwalder, A., C. Bak. 13: 207, 1904.

375 Morse, W. T. and Lewis, C. E., Maine B. 185: 1910.

3 Smith, E. F., Sc. $1: 755, 1910.

377 Briosi, Att. d. R. Acad. d. Lincei Roma Ser. 2: 3.

38 Proc. W. N. Y. Hort. Soc. 43: 9, 1898.

379 Sheldon, J. L., Neb. R. 23, 1904.

30 Smith, E. F., V. P. P. B. 17: 1899.

381 Atkinson, G. F., Ala. B. 4/: 19, 1892.

382 Orton, W. A., V. P. P. B. 27: 1900.

383 Higgins, B. B., N. C. R. 32: 100, 1909.

384 Chester, F. D., Del. R. 3: 89, 1890.

388 Detmers, F., Ohio B. 44: 147, 1892.

38 von Hall, Ber. deut. Bot. Gez. 21: 2.

87 Schikorra, G., Diss. 1906.

388 Butler, Mem. Dept. Agr. India, Bot. Ser. 2: 9, 1910.

¢ Smith, E. F., Proc. A. A. A. 8. 190, 1895.

30 Smith, E. F., Proc. A. A. A. S. 43: 289, 1894.

3*1 Bubak, Fr., Ber. d. deut. Bot. Ges. 29: 73.

32 Smith, R. E., Mass. B. 79, and Mass. R. 57, 1902.

33 Reed, H.S., Sc. 23: 751, 1906.

3 Stone, G. E., and Smith, R. E., Mas. B. 69: 1900.

395 Manns, T. F., O. B. 229: 1911.

26 Smith, E. F. and Swingle, D. B., B. P. I. B. 55: 1904.

37 Stewart, F. C., N. Y. (Geneva) B. 101: 85, 1896.

28 Wehmer, C., C. Bak. 3: 727, 1897.

a Clinton, G. P., Ill. B. 40: 139, 1895.

676 THE FUNGI WHICH CAUSE PLANT DISEASE

40 Oven., Landw. Jahr. 34: 489, 1905.

401 Massee, Gard. Chron. Ser. 3: 17, 707.

42 Smith, R. E., Cal. B. 175: 8, 1906.

43 Bolley, H. L., N. D. B. 60: 1901.

4 Harter, L. L., Sc. 30: 934, 1910.

405 Osterwalder, A., Land. Jahr. Schw. 24: 247.

46 Galloway, B. T., Amer. Gard. 17: 518, 1896.

47 Smith, R. E., Mass. B. 79: 1902.

408 Stewart, F. C., N. Y. (Geneva) B. 164: 219, 1899.

«9 Sturgis, W. C., Ct. R. 21: 175, 1897.

40 Chifflat, J., Jour. Soc. Nat. Hort. France, 4: Ser. 8, 348.
«1 Pollock, J. B., Sc. 31: 638, 1910.

412 Prillieux and Delacroix, C. R. 131: 961, 1900.

41,.N. 8. R. Wales, 93.

414 Doherty, M. W., Bot. Gaz. 30: 400, 1900.

415 Rept. Mo. Bot. Gard. 9: 159, 1898.

416 Sci. 14: 899, 1901. ;

417 Duggar, B. M., N. Y. (Cornell) B. 163, 1899.

418 Stone and Smith, Mass. R. 67: 1897.

«9 Heald, F. D., Phytop. 7: 108, 1911.

420 Giissow, H. T., Zeit. 16: 135, 1906.

421 Stevens, F. L. and Wilson, W. G., Sc. 33: 943, 1911.
422 Scholz, E., Verh. K. K. Zool. Bot. Ges. Wien, 47: 541.
423 Selby, A. D., O. B. 92.

424 Bertoni, W. S., Rev. Agr. Cien. Apt. Paraguay 1: 211.
«25 Harle, F.8., Ala. B. 108: 1900.

40 Stout, A. B., Sc. 33: 156, 1911.

427 Klebahn, H., Jahr. d. Hamb. Wiss. Ans. 22.

428 Shear, C. L., Bull. Tor. Bot. Club 34: 305, 1907.

429 Atkinson, G. F., Bot. Gaz. 18: 16, 1893.

430 Pammel, L. H., Tex. R. 2: 61, 1889.

481 Pammel, L. H., B. Tex. 4: 1888.

432 Shear, C. L. and Miles, G. F., B. P. I. B. 102: 39, 1907.
433 Galloway, B. T., and Woods, A. F., Y. B. 248, 1896.
484 Stewart, F. C. and Blodgett, F. H., N. Y. (Geneva) B. 167: 283.
435 Johnston, T. H., Agr. Gaz. N. 8. Wales 21: 563.

438 Stevens, F. L. and Hall, J. G., N. C. R. 31: 72, 1909.
437 Swingle, W. T., and Webber, H. J., V. P. P. B. 8: 32, 1896.
438 Fulton, H. R., La. B. 101: 1908.

489 Porto Rico R. 449: 1903.

«© Arthur, J. C., N. Y. (Geneva) R. 4: 250, 1885.

BIBLIOGRAPHY OF FUNGI IMPERFECTI 677

441 Laubert, R., Gartenflora 59: 409, 1910.

442 Chester, F. D. Del, 6: 111, 1893.

443 Peck, N. Y. St. Mus. Nat. Hist. B. 157: 21.

444 Bot. Gaz. 54: 231.

445 Se. 37: 638.

446 Cordley, Ore. Sta. Bienn. Crop. Rept. & Hort. R. 1911-12, 187:
1913.

447 Stone, Ann. Myc. 10: 564, also Melhus, Phytop. 3: 56.

448 Stewart, F. C. N. Y. (Geneva) B. 328, 387.

449 Ann. Myc. 10: 491.

450 Gussow, Canada Exp. Farms. R. 1912, 202.

431 Ann. Myc. 6: 112.

452 Peck, N. Y. Mus. R. 32: 41.

453 Chester, F. D., Del. B. 70: 13.

454 Giissow, Zeit. 16: 10.

435 Heald, F. D., Mycol. 1: 215, 1909.

4566 Wehmer, C., C. Bak. 3: 646, 1897.

457 Percival, J., Jour. Southeast Agr. Col. Wye, 81: 1902.

458 Chiffat, J., Jour. Soc. Nat. Hort. France, Ser. 4, 8, 348.

459 Arthur, J. C., Ind. B. 19: 5, 1889.

SOME OF THE MOST USEFUL BOOKS

. Buller Researches on Fungi.
. A. De Bary: Comparative Morphology & Biology of the Fungi Myce-

tozoa & Bacteria. Clarendon Press, 1887.

. G. Delacroix and A. Maublane: Maladies des Plantes Cultivées.

J. B. Bailliere & Fils, 1909.

. Ducomet: Pathologie Végétale, Chas. Amat, 1908.
. B. M. Duggar, Fungous Diseases of Plants. Ginn & Co., 1909.
. A. Engler: Syllabus der Pflanzcnfamilien, Gebriider Borntreger,

1907.

. Engler and Prant: Natiirliche Pflanzenfamilien, Wm. Engelmann,

1897.

. W. G. Farlow: Bibliographical Index to N. American Fungi, Car-

negie Inst. of Washington, 1905.

. Farlow & Seymour: Host Index of the Fungi of the U. S., Cambridge,

1888.

. A. B. Frank: Die Pilzparasitdéren Krankheiten der Pflanzen. Ed.

Trewendt, 1896.

. E. M. Freeman: Minnesota Plant Diseases, Pioneer Press, 1905.
. K. Goebel: Outlines of Classification & Special Morphology of Plants,

Clarendon Press, 1887.

. R. Hartig: The Diseases of Trees.

. R. Hartig: Lehrbuch d. Pflanzenkrankheiten, Julius Springer, 1900.
. Ideta: Text-book of Plant Diseases, Japanese.

. O. Kirchner: Die Krankheiten und Beschddigungen unserer land-

wirtschaftlichen Kulturpflanzen. Eugen Ulmer, 1906.

. Ernst Kiister: Pathologische Pflanzenanatomie, Gustav Fischer,

1903.

. Franz Lafar: Handbuch d. Technischen Mykologie, Gustav Fischer,

1904-1907.

. Lindau in P. Sorauer: Handbuch d. Pflanzenkrankheiten. Paul

Parey, 1908.

. Lindau and Sydow, Thesaurus Literature Mycologice.
. Lotsy: Vortrige tiber botanische Stammesgeschichte; Gustav Fischer,

1907.
678

22.

23.
24.
26.

26.
27.

29.
30.
31.

32.

33.
34,
35.
36.

37.
38.

39.

40.
41.
42.
43.
44,

45.
46.
47.
48.
49.
50.
61.
62.

SOME OF THE MOST USEFUL BOOKS 679

Geo. Massee: Diseases of Cultivated Plants and Trees. Duckworth &
Co., 1910.

Geo. Masses: Text-book of Fungi, Duckworth & Co., 1906.

E. Prillieux: Maladies des plantes agricoles.

P. A. Saccardo: Sylloge Fungorum, Pavia; R. Friedlander & Sohn _
1882.

Stevens and Hall: Diseases of Economic Plants, Macmillan Co., 1910.

Tubeuf and Smith: Diseases of Plants Induced by Cryptogamic
Parasites, Longmans, Green & Co., 1897.

L. M. Underwood: Moulds, Mildews and Mushrooms. Henry Holt &
Co., 1899.

-H. Marshall Ward: Disease in Plants. Macmillan & Co., 1901.

Strasburger, Noll, Schenck and Karsten: Text-book of Botany, 1908.

F. D. Chester: Manual of Determinative Bacteriology. Macmillan &
Co., 1901.

H. W. Conn: Agricultural Bacteriology. P. Blakiston’s Son & Co.,
1909.

A. Fischer: Vorlesungen ueber Bakterien, Gustav Fischer, 1903.

C. Fliigge: Die Mikroorganismen. F. C. W. Vogel, 1896.

E. O. Jordan: General Bacteriology. W. B. Saunders Co., 1908.

J. G. Lipman: Bacteria in Relation to Country Life. Macmillan &
Co., 1908.

W. Migula: System der Bakterien. Gustav Fischer, 1897.

Miquel et Cambier: Traité de Bacteriologie Pure et Appliquée.
Masson et Cie, 1902.

E. F. Smith: Bacteria in Relation to Plant Diseases. Carnegie In-
stitution, Sept., 1905.

A. Lister: The Mycetozoa, 1895.

Geo. Massee: Monograph of the Myxogastres, 1892.

H. Macbride: North American Slime-Moulds. Macmillan, 1899.

Rostafinski: Sluzowce Monografia, 1875.

Torrend: Les Myxomycétes. Brotevia 7: 5, 177; pl. 1-9, also sepa-
rate, 1908.

Plowright, British Uredinee & Ustilaginee.

Salmon, Monograph of the Erysiphacez.

Clinton,°G. P., North American Flora, Ustilaginales.

Murrill, W. A., North American Flora, Polyporacee, etc.

Arthur, J. C., North American Flora, Urediniales.

Atkinson, G. F., Mushrooms.

Clements, The Genera of Fungi.

Ellis and Everhart, North American Pyrenomycetes.

680 THE FUNGI WHICH CAUSE PLANT DISEASE

53

64.

55.
56.
67.
58.
59.
60.
61.
62.
63.

64

. Rabenhorst, Kryptogamen Flora von Deutschland.

Bancroft, K., Handbook of the Fungous Diseases of West Indian
Plants, 1910.

Hartig, The Diseases of Trees, Trans. by Sommerville.

McAlpine, Rusts of Australia.

Jaczewski, A. A., Phytopathology (Russian).

Noél Deer: Sugar Cane. Norman Rodger, Manchester, 1911.

Klebahn, H., Die Wirtwechselnden Rostpilze, 1894

Sydow, Monographia Uredinearum, 1904.

Holway, E. W. D., North American Uredinee, 1905.

Seaver, North American Flora, 3: Pt 1.

Viala, R., Les Maladies de la Vigne.

. P. Hariot, Les Uredinées, Paris, 1908.

Periodicals of use to the Phytopathologist

Phytopathology.

Annales Mycologici.

Centralblatt fiir Bakteriologie U. Paristenkunde IT. Abt.
Hollrung’s Jahresbericht u. d. Gebeit der Pflanzenkrankheiten.
Experiment Station Record.

Zeitschrift fiir Pflanzenkrankheiten.

Rivista di Patologia vegetale.

Hedwigia.

Mycologia, formerly Journal of Mycology.

Pr:
Ju

actische Blatter fiir Pflanzenschutz.
st’s Botanischer Jahresbericht.

Bulletin Trimestriel de la Sociétié Mycologique de France.

For Bibliographies of special articles, see pages 53, 109, 288, 466, 666.

GLOSSARY

A

A, privative. Signifying without.

Acervulus (i). A small cluster, tuft of mycelium bearing spores.

Acicular. Slender or needle-shaped.

Acrogenous. Growing at the apex.

Acropetal. Produced in a succession towards the apex.

Adnate. Attached the whole length.

Eciospore. icidiospore. A spore formed in an ecium.

Ecium (a). AEcidum (a). A special form of sorus in the Uridinales.

Aérial. Living above the surface of the ground or water.

Aérobic. Aérobiotic. Requiring oxygen.

thalioid. Like an ethalium.

thalium (a). A compound sporiferous body formed from a large
combination of plasmodia.

Agglutinated. Agglutinate. Glued together.

Aggregated. Aggregate. Collected together.

Allantoid. Sausage-shaped, crescent-shaped with rounded ends.
Alveola (z). Cavities or pits on the surface. Alveolate. Pitted like
a honeycomb. Alveolar. Pertaining to or resembling Alveole.
Ameboid. Like an amceba, exhibiting creeping movement by pseudo-

podia.
Amorphous. Shapeless. .
Amphigenous. Growing all round an object, not restricted to any par-
ticular surface.
Ampulliform. Swollen out. Flask-shape.
Anastomosing. Uniting and forming a network.
Angiocarpous. Invested by some covering.
Annulate.. Ring-shaped or with a ring.
Annulus. A ring-like portion of the ruptured marginal veil, after the
expansion of the pileus.
Anoderm. Without a skin.
Antheridium (a). In fungi the male sexual organ.
Apical. At the point of any structure.
Apicula. A sharp and short, but not stiff point.
681

682 GLOSSARY

Apogamous. Showing apogamy.

Apothecium (a). An ascocarp in which the hymenium lies exposed
while the asci are maturing. _

Appendages. Processes of any kind.

Appendiculate. Furnished with appendages.

Appiculate. Furnished with an appicula.

Appressed. Lying flat for the whole length.

Appresoria. Organs of attachment of germinating parasites.

Approximate. Close together, but not united.

Arachnoid. Like a cobweb.

Arcuate. Curved.

Areola (@). A space marked out on a surface.

Aristate. Awned.

Armilla, A bracelet-like frill.

Armilla-form. Armilla-like.

Ascigerous. Bearing asci.

Ascocarp. A sporocarp producing asci.

Ascogenous. Producing asci.

Ascogonium. In ascomycetous fungi, the cell or group of cells fer-
tilized by a sexual act.

Ascoma. Receptacle and hymenium of the larger fungi.

Ascoplasm. Protoplasm of the ascus.

Ascus (i). A large cell in the ascocarp in which spores are developed,
usually eight.

Aseptate. Without cross-divisions.

Asexual. _Destitute of male and female organs.

Asperate. Rough with hairs or points

Attenuate. Tapered.

Auriform. Ear-shaped.

Auteecious. A parasite which runs its whole course on a single host.

Avellaneous. Drab, hazel, hazel-nut-brown.

B

Bacillar. Bacilliform. Rod- or club-shaped.

Basal. At the base of..

Basidiospore. A spore acrogenously abjointed upon a basidium.

Basidium. The mother-cell from which spores are acrogenously
abjointed.

Basipetal. Growth in the direction of the base.

Bay. Reddish brown or chestnut color.

Biogenous. Growing on living organisms.

GLOSSARY 683

Botryose. Racemose.
Bullate. Blistered or puckered.
Byssoid. Flax-like or cottony.

Cc

Calcareous. Chalk-white, chalky.

Campanulate. Bell-shaped.

Cancellate. Latticed, as in Clathrus.

Capillitium. Sterile thread-like tubes or fibers, mixed with the spores
within a sporangium.

Capitate. Having a head.

Carbonous. Carbonaceous. Dark colored. Consisting chiefly of sub-
stances in which carbon predominates.

Carpogonium (a). Part of a procarp resulting in a sporocarp after
fertilization.

Cartilagenous. Hard and tough.

Castaneous. Chestnut-colored.

Catenulate. Concatenate. Formed of parts united or linked as in
a chain.

Caulicolous. Living on stems.

Cespitose. Growing in tufts.

Chlamydospore. A spore having a very thick membrance.

Chromogenesis. Color production.

Chromogenic. Chromogenous. Color-producing.

Ciliate. Fringed with hairs.

Cilium (a). Vibratile whip-like processes of protoplasm by which
zodspores and similar bodies move.

Cinereous. Cineraceous. Ashy.

Circinate. Circinnate. Coiled into a ring or partially so.

Circumscissile. Dehiscing as if cut circularly around.

Cirrhose. Cirrose. Cirrhous. Having a cirrhus or tendril.

Clathrate. Latticed.

Clavate. Club-shaped, thickened towards the apex.

Clypeate. Buckler or shield-shaped, having a clypeus.

Clypeus. A buckler or shield-shaped tissue around the mouth of a
perithecium.

Cenocyte. A multinucleate cell.

Collabent. Collapsing.

Colliculose. With little round elevations.

Columella. Sterile axile body within a sporangium.

684 GLOSSARY

Columnar. Having the form of a column.

Compound. Similar parts aggregated into a common whole.

Con or Com. In Latin compounds signifying with.

Conchate. Shell-shaped.

Concolorous. Of one color.

Confluent. Blended into one.

Conglobate. Collected into a ball.

Conidiophore. A sporophore bearing a conidium.

Conidiospore. Same as conidium.

Conidium (a). Dust-like spores usually produced directly from the
hyphe.

Conjugation. Union of two like gametes to form a zygote.

Connate. United.

Constricted. Drawn together; contracted.

Context. The flesh of a mushroom and the corresponding substance in
other pileate fungi.

Continuous. The reverse of interrupted.

Convoluted. Convolute. Rolled round.

Coremium. The name of a genus of fungi, derived from a Greek word
meaning broom.

Coriaceous. Leathery.

Corneous. Of horny texture.

Cortex. The bark or rind. The peridium of Fungi.

Cortical. Relating to the cortex.

Costate. Ribbed.

Crateriform. Globet or cup-shaped.

Cristate. Crested.

Cruciate. Cross-shaped.

Crustose. Crust-like.

Cuboid. Resembling a cube.

Cupulate. With a cupule.

Cupuliform. Shaped like a small cup.

Cuticle. The outermost skin.

Cuticulate. Having a cuticle.

Cylindric. Cylindrical. Elongated, with a circular cross-section.

Cyme. Cluster of determinate or centrifugal type, especially a broad
and flattened one.

Cyst. A sac or cavity.

Cystidium (a). Large, one-celled, sometimes inflated bodies, projecting
beyond the basidia and paraphyses of the hymenium of Agarics.

Cytolitic. A ferment which dissolves the cell-wall.

GLOSSARY 685

D

Deciduous. Falling in season.

Decumbent. Reclining with the summit ascending.

Decurrent. Running down.

Definite. Precise; of a certain number.

Dehiscence. The mode of opening.

Deliquescent. Dissolving or melting away.

Dendritic. Having a branched appearance.

Dendroid. Tree-like in form, or branching.

Denticulate. Minutely toothed.

Depressed. Sunk down, flattened.

Determinate. Definite.

Di. Two or double.

Dichotomous. Forked.

Dichotomy. Forking in pairs.

Difform. Of double form, irregular.

Diffuse. Widely or loosely spreading.

Digitate. Fingered: compound. As in the Horse Chestnut leaf.

Dimidiate. Halved, as when half an organ is so much smaller than the
other as to seem wanting.

Disciform. Flat and circular.

Discoid. Resembling a disk.

Disculate. Having a disk.

Disjunctors. Spindle-shaped cellulose connections between conidia.

Dissepiment. A partition.

Doliform. Barrel-shaped.

E

E, Ex. Privative in Latin compounds.
Echinulate. Having small prickles.
Effuse. Expanded.

Ellipsoid. Ellipsoidal. Elliptic. Like an ellipse.
Embedded. Surrounded in.

Endogenous. Produced within.
Endophyte. Growing inside another plant.
Endophytic. As an endophyte.
Endospores. Spores formed endogenously.
Endozoic. Living inside an animal.

Entire. With even margin.

686 GLOSSARY

Entomogenous. On insects.

Enzyme. An unorganized or soluble ferment.
Epi. In Greek compounds to mean “ upon ”.
Epiphy!ous. Growing on leaves.

Epispore. Outer coat of a spore.

Epithecium. The surface of the fructifying disk.
Epixylous. Growing on wood. i
Erumpent. Breaking through.

Evanescent. Soon disappearing.

Excipuliform. Wart-like.

Exospore. The outer covering of the spore.
Explanate. Spread out flat.

Exserted. Protruding beyond.

F

Facultative. Occasional, incidental as opposed to obligate.

Falcate. Sickle-shaped.

Fascicle. A little bundle.

Fasciculate. In clusters or bundles.

Favoid. Like a honeycomb.

Ferruginous. Ferrugenous. Ferrugineous. Rust-colored.

Fibrillous. Fibrillose. Furnished with fibers.

Filamentous. Of free hyphze which are at most loosely interwoven
but without forming bodies of definite shape and outline.

Filiform. Thread-shaped.

Fimbriate. With the margin bordered by long slender processes.

Fission. Splitting.

Flabelliform. Shaped as a fan.

Flaccid. Limp, flabby.

Flagellate. Provided with whip-like processes.

Flagellum (a). Whip-like process of protoplasm of a swarmspore.

Flavous. Nearly pure yellow.

Fleshy. Succulent.

Flexuose. Flexuous. Bent alternately in opposite directions, zigzag.

Flocci. Locks like soft hair or wool.

Floccose. Bearing flocci.

Flocculent. Diminutive of Floccose.

Fluorescence. The property of diminishing refrangibility.

Fluorescent. Exhibiting fluorescence.

Fetid. Fetid, stinking.

GLOSSARY 687

Foliar. Leafy or leaf-like. On a leaf.
Foliicolous. On leaves.

Free. Not adhering.

Fructicolous. Living on fruit.

Fruticolous. Living on shrubs.

Fruticose. Shrubby.

Fugacious. Soon perishing.

Fuligineus. Fuliginous. Sooty, or soot-colored.
Fulvous. Yellow, tawny.

Fumaginous. Smoky; sooty.

Furcate. Forked.

Fuscous. Dusky, too brown for a gray.
Fusiform. Thick but tapering towards each end.
Fusoid. Somewhat fusiform.

G

Gametangium (a). A differentiated cavity, which produces gametes.
Gamete. A sexual protoplasmic body.

Gemma (2). A young bud.

Gemmation. Budding.

Gemmiform. Bud-shaped.

Gill. The plates or lamelle of an Agaric.

Glabrous. Without hair.

Gleba. The gelatinous spore mass in the Phallales.

Globoid. Rounded.

Globose. Nearly spherical.

Glomerate. Agglomerate, collected into heads.

Granular. Composed of grains.

Gregarious. Growing in company. Associated but not matted.
Guttulate. Resembling drops, with drops.

Gymnocarpous. Naked fruited.

Gyrose. Curved backward and forward in turn.

H

Hamate. Hooked at the tip.

Haustorium (a). Special branch of a filamentous mycelium serving
as an organ of attachment and suction.

Heterecism. Condition of a hetercecious parasite.

Hetereecious. Passing its stages on more than one host.

Heterogamy. With gametes not uniform.

688 GLOSSARY

Heteromorphic. Heteromorphous. Variation from normal structure,
as having organs differing in length; dimorphic.

Hirtose. Hirtus. Hairy; hirsute.

Hispid. Bristly.

Hoary. Gray from fine pubescence.

Host. A plant which nourishes a parasite.

Hyaline. Colorless or translucent.

Hyaloplasm. The hyaline matrix or clear non-granular portion of pro-
toplasm.

Hymenium (a). An aggregation of spore mother-cells in a continuous
layer on a sporophore.

Hymenophore. That part which bears the hymenium.

Hypha (2). The thread-like vegetative part of a fungus.

Hyphoid. Resembling hyphe.

Hypertrophy. An abnormal enlargement of an organ.

Hypophyllous. Situated under a leaf.

Hypopodium (a). The stalk or support.

Hypothallus. The marginal outgrowth of hyphe often strand-like,
from the thallus.

Hypothecium. A layer of hyphal tissue immediately beneath the
hymenium.

Hysterioid. Elongated boat-shaped, resembling the genus Hysterium.

I

I, 11, Ill. Symbols for the stages of the rusts, see p. 324, 326.

Imbricate. Overlapping as the tiles on a roof.

Immersed. Below the surface.

Imperforate. Without an opening.

Incrassation. Thickened growth.

Indehiscent. Not opening along regular lines.

Indeterminate. Not terminated definitely.

Indurate. Hardened.

Infundibuliform. Shaped like a funnel.

Innate. ‘Born on the apex of the support. Imbedded.

Intercalary. Growth which is not apical but between the apex and the
base.

Intercellular. Between cells.

Intracellular. Inside a cell.

Intramycelial. Within the mycelium.

Involute. Enwrapped, having the edges of the leaves rolled inwards.

Irpiciform. Having teeth resembling those in Irpex.

GLOSSARY 689

Isabelline. A dirty tawny tint.
Isogamous. Used for those plants which produce like gametes.
Isogamy. Conjugation of two gametes of similar form.

K

Keeled. Carinate.

L

Labyrinthiform. Marked by sinuous lines.

Lacerate. Torn, or irregularly cleft.

Lactiferous. Latex bearing.

Lamella (2). The gills of Agaricales.

Lamellate. Made up of thin plates.

Lamelliform. In the shape of a plate or scale.

Lamelloid. Resembling lamella.

Lageniform. Shaped like a Florence flask.

Lanceolate. Narrow, tapering to each end.

Latericious. Lateritious. Brick-red.

Latticed. Cross-barred.

Lax. Loose, distant.

Lenticular. Shaped like a double convex lens.

Lichenoid. Irregularly lobed as lichens.

Lignicole. Growing on wood.

Limoniform. Lemon-shaped. .

Linear. Narrow, several times longer than wide.

Lipochrome. A yellow pigment.

Lobate. Lobed. Divided into or bearing lobes.

Locule. Loculus. A cell or cavity.

Lumen. The space which is bounded by the walls of an organ, as the
central cavity of a cell.

M

Macro. Mega. In Greek compounds to signify large.

Maculicole. On spots.

Mammiform. Breast-shaped.

Marginate. Broad-brimmed, furnished with a margin of distinct char-
acter.

Matrix. The body on which a Fungus or Lichen grows.

Melleus. Melleous. Like honey.

690 GLOSSARY

Membranous. Membranaceous. Thin and semi-transparent, like a
fine membrance.

Medullary. Relating to the pith, pithy.

Micro. To signify small, little.

Microsporangium (a). A sporangium which produces microspores.

Mon. In Greek compounds to signify one.

Monopodium (a). An axis which continues to grow at the apex in
the direction of previous growth, while lateral structures of like
kind are produced beneath it in acropetal succession.

Monosporic. Bearing one spore.

Monostichous. In asingle vertical row.

Mucose. Slimy.

Multi. A Latin element signifying many or much.

Muricate. Rough with short hard excrescences.

Muriculate. Diminutive of Muricate.

Muriform. With cells resembling bricks in a wall, with both longitudi-
nal and transverse septa.

Muticous. Muticate. Pointless, blunt.

Mycelium. Vegetative portion of thallus of fungi composed of one or
more hyphe.

Myxameeba (2). Swarm-cells with purely amceboid creeping motion.

N

Nodose. Knotty or knobby.
Nodule. A small knot or rounded body.

O

O. Asymbol for the pyenial stage of the rusts.

Ob. As a prefix meaning inversely or oppositely.

Obese. Excessively fat; fleshy.

Obligate. Necessary, essential. Comp. Facultative.

Obsolete. Wanting or rudimentary.

Ochraceous. Ocher-colored, yellow with a tinge of red.

Olivaceous. The color of a ripe olive.

Odégonium. Female sexual organ, containing one or more odspheres.

Oésphere. Naked mass of protoplasm which, after fertilization, develops
into the odspore.

Odspore. Immediate product of fertilization of odsphere.

Opalescent. Reflecting an iridescent light.

Operculate. Furnished with a lid.

GLOSSARY 691

Operculum. A lid or cover which separates by a transverse line of
division.

Opt. Abbreviation for Optimum.

Ostiolate. Bearing an ostiole.

Ostiole. An opening or mouth.

Oval. Broadly elliptic.

Ovate. Shaped like a longitudinal section of a hen’s egg.

Ovoid. Resembling an egg.

P

Pannose. Felt-like.

Papilla (z). Soft superficial protuberances.

Papillate. Having papille.

Papilliform. Shaped like a papilla.

Papilloid. Resembling a small nipple.

Paraphysate. With paraphyses.

Paraphyses. Sterile filaments occurring in the fructification of erypto-
gams.

Parasite. An organism living on or in and at the expense of another
living organism (the host).

Patellate. Shaped like a patella.

Patelliform. Like a small dish, circular and rimmed.

Pedicel. The support.

Pedicellate. Borne on a pedicel.

Pellicle. A small skin; a delicate superficial membrane.

Pellucid. Wholly or partially transparent.

Penicillate. Like a little brush. Pencil-shaped.

Perforate. Pierced through.

Peridium. The outer enveloping coat of a sporangium.

Periplasm. The protoplasm in the odgonium and the antheridium
which does not share in conjugation.

Perithecium. A rounded, oval, pyriform or beaked structure in which
asci are borne.

Peritrichiate. With hairs from all of surface.

Persistent. Remaining till the part which bears it is wholly matured.

Phycochrome. The coloring matter of brown Alge.

Phyllogenous. Growing upon leaves.

Phytogenous. Growing on plants.

Pileate. Having the form of a cap.

Pileiform. Pileus-shaped.

Pileus. Cap. The dome-shaped part of a sporophore.

692 GLOSSARY

Pilose. Pilous. Hairy, having soft and distinct hairs.

Planose. Plane.

Plasmodiocarp. An asymmetrical sporangium of the Myxogastres.

Plasmodium. Body of naked plurinucleated protoplasm exhibiting
amoeboid motion.

Pleurogenous. Growing from the sides.

Plexus. A network.

Plicate. Folded into plaits usually lengthwise.

Polar. Relating to the poles of an organ.

Polymorphic. Polymorphous. With several or various forms, variable
as to habit.

Polysporic. Many spored.

Porcelaneous. Like porcelain.

Poroid. Resembling pores.

Porose. Containing pores.

Proliferous. Bearing offshoots.

Promycelium. Short and short-lived product of tube-germination of
a spore which adjoins acrogenously a small number of spores
(sporidia) unlike the mother-spore and then dies off.

Pseudo. In prefix signifying false, counterfeit, spurious.

Pulverulent. Powdered, as if dusted over.

Pulvinate. Cushion-shaped.

Punctiform. In the form of a point or dot.

Punctulate. Marked with small points.

Pustular. Blister-like, bearing blisters.

Pustule. A pimple or blister.

Pustuliform. Having slight blister-like elevations.

Putrescent. Becoming rotten.

Pycnidium (a). A variously shaped cavity resembling a pyrenocarp
and containing conidia.

Pycniospore. Spores borne in pycnia.

Pycnium. A structure of the Uridinales; see pp. 324-326.

Pycnosclerotia. Sclerotia bearing pycnidia.

Pycnospores. Spores from pycnidia.

Pyriform. Piriform. Resembling a pear in shape.

R

Radiate. Spreading from or arranged around a common center.
Ramicole. Growing on branches.

Ramose. Branched.

Receptacle. That part which bears one or more organs.

GLOSSARY 693

Reniform. Kidney-shaped.

Resupinate. Without a pileus.

Reticulate. Netted, like network.

Revolute. Rolled back from the margin or apex.
Rhizoid. A root-like structure.

Rhizomorph. A root-like branched strand of mycelial hyphe.
Rhomboidal. Approaching a rhombic outline.
Rimose. Rimous. Cracked.

Rostrate. With a beak.

Rostrum. Any beak-like extension.

Rufous. Reddish.

Rugose. Rugous. Covered with wrinkles.

iS)

Saccate. Bag-shaped.

Saprophyte. A plant living on dead organic substance.

Sarcineform. Having the form of the genus Sarcina.

Scabrous. Rough to the touch.

Sclerotioid. Like a sclerotium.

Sclerotium. A compact mass of hyphe in dormant state.

Scopulate. Broom-like or brush-like.

Scorpioid. With the main axis coiled like the tail of a scorpion.

Scrupose. Jagged, rough. ,

Scutiform. Buckler-shaped.

Septate. Divided by a partition.

Septum (a). Any ‘kind of partition.

Seriate. In a series.

Sessile. Destitute of a stalk.

Seta(z). A bristle or bristle-shaped body.

Setaceous. Bristle-like.

Setose. Bristly, beset with bristles.

Setulose. Resembling a fine bristle.

Shield-shaped. In the form of a buckler; clypeate, peltate, or scutate.

Sigmoid. Doubly curved in opposite directions, like the Greek sigma.

Simple. Of one piece or series, opposed to compound.

Sinuous. Sinuose. Sinuate. With a deep wavy margin.

Sorus (i). Heap, or aggregation; a heap of spores.

Spatulate. Like a druggist’s spatula.

Sperm. A male reproductive cell.

Spermatum (a). Male non-motile gamete, sometimes erronously used
for various conidia.

694 GLOSSARY

Spheroidal. Somewhat spherical.

Spindleform. Spindle-shaped, fusiform.

Sporangiophore. A sporophore bearing a sporangium.

Sporangium. Sac producing spores endogenously.

Spore. A single cell which becomes free and is capable of developing
directly into a new plant.

Sporidium. Diminutive of spore, especially applied to the spores pro-
duced on promycelia.

Sporocarp. A many-celled body serving for the formation of spores.

Sporodochium. The sporiferous apparatus in fungi belonging to
the Tuberculariales.

Sporogenous. Producing spores.

Stellate. Star-shaped or radiating like the points of a star.

Sterigma (ta). A stalk-like branch of a basidium bearing a spore.

Stipe. A general term for stalk.

Stipitate. Having a stipe.

Stolon. A sucker or runner.

Stoloniferous. Bearing stolons.

Stratose. In distinct layers.

Striate. Marked with fine longitudinal parallel lines.

Strigose. With sharp-pointed appressed straight and stiff hairs or
bristles.

Stroma (ta). A cushion-like body, on or in which the perithecia are
immersed.

Stromatic. Pertaining to or resembling a stroma.

Stuffed. Solid, farctate.

Stylospore. A spore borne on a filament.

Sub. Under or below; in compounds usually implies an approach to the
condition designated; somewhat or slightly.

Subiculum. Subicle. A felted or byssoid basal stratum of hyphe.

Subulate. Awl-shaped.

Sulcate. Grooved or furrowed.

Superficial. On the surface.

Suspensor. A club-shaped or conical portion of hypha adjoining a
gamete-cell.

Sympodium. An axis made up of the bases of a number of successive
axes arising as branches in succession one from the other.

Syn. Signifies adhesion or growing together.

Synema. A column of combined filaments.

GLOSSARY 695

T

T.D.P. Abbreviation for Thermal-death-point.

Teleutospore. A resting spore of Uridinales on germination producing
a promycelium.

Teleuto-stage. Stage producing a teleutospore.

Telium. A sorus of the Uredinales; see pp. 324-326.

Terete. Circular in transverse section.

Ternate. In threes.

Thalloid. Having the nature or form of a thallus.

Thallus. A vegetative body without differentiation into stem and leaf.

Tomentose. Densely pubescent with matted wool, or short hairs.

Tortuous. Bent or twisted in different directions.

Torulose. Irregularly bending. Somewhat moniliform with swollen
portions.

Tremelliform. Gelatinous in texture.

Tremelloid. Jelly-like in substance or appearance.

Trichogyne. The receptive filament of the female organ.

Trident. Having three teeth.

Triquetrous. Three-edged, with three salient angles.

Truncate. As though cut off at the end.

Tubercular. Having tubercles, or like a tubercle.

Tuberculate. Beset with knobby projections or excrescences.

Tubular. Cylindrical and hollow.

Tumid. Inflated, swollen.

U

Umbellate. Having the inflorescence in umbels.

Umbilicate. Navel-like.

Umbo. A boss.

Umbrinaceous. Umbrinous. Umbrinus. Umbrinose. The color of
raw umber.

Uncinate. Hooked.

Ungulate. Having claws or hoofs.

Unguliform. Hoof-shaped.

Uni. In composition, one, or single.

Urceolate. Urceolar. Pitcher-like, hollow and contracted at the mouth
like an urn.

Uredinium. A sorus in the Uredinales, see pp. 324-326.

696 GLOSSARY

Vacuolate. Possessing vacuoles.
Valsoid. Resembling Valsa.
Valvate. Opening by valves.
Vegetative. Growing.
Veil. A special envelope in Agaricales within which the growth of the
sporophore takes place.
“Velutinous. Velvety, due to a coating of fine soft hairs.
Vermicular. Vermiculate. Worm-shaped, thickened and bent in places.
Verruciform. Wart-shaped.
Verrucose. Verrucous. Verruculose. Full of warts. Warty.
Verticillate. Whorled.
Vesicular. Composed of vessels.
Villi. Long weak hairs.
Villous. Bearing villi.
Vinose. Vinous. Wine colored.
Viscid. Sticky from a tenacious coating or secretion.
Volva. A covering, the sac enclosing the Agaric sporophore.

Z

Zonate. Marked circularly.

Zodglez. A colony embedded in a gelatinous substance.
Zoodsporangia. Sporangia which produce zodspores.
Zoodspore. A motile spore.

INDEX

(Boldface figures refer to headings, italic figures to illustrations)

A Actiniceps, 634
Actinida, 181
Abies, 229, 230, 347, 391, 416, 558, Actinomma, 656

560 Actinonema, 505, 508
Absidia, 104 —— Fagicola, 609
Acacia, 436, 457 —— Fraxani, 509
Acanthorhynchus, 224 —— Rose, 508, 508
Vaccinii, 224, 225 Tiliz, 609
Acanthostigma, 226, 229 Actinothecium, 528
Parasiticum, 229, 229 Actinothyrium, 532
Acer, 188, 202, 499, 507, 529 Adonis, 178
Pseudoplatanus, 152, 159 AKcidium, 324, 334, 335, 389, 390
Aciculosporium, 199 —— Abietinum, 349
Acinula, 659 —— Asperifolium, 381
Acladium, 575 —— Berberidis, 334, 378
Acolium, 153 Brassice, 378, 390
Aconitum, 93 —— Cinnamomi, 390
Acontium, 571 —— Columnare, 347
Acorus, 73, 320 — Cyparissiz, 372
Acrasiales, 5 —— Euphorbie-gerardiane, 375
Acremoniella, 600, 600 —— Grossularie, 376
—— Occulta, 600 —— Leucospermum, 336
Verrucosa, 600 —— Mespili, 371
Acremonium, 575, 677, 577 —— Otogense, 390
Acrocylindrium, 583 —— Orxalidis, 384
Acrocystis, 663 —— Pelargonii, 390
Batate, 663 —— Rhamni, 382
Acrospeira, 599 —— Rubellum, 377
Acrospermacee, 160 Strobilinum, 347
Acrostalagmus, 583, 684, 684 —— Tuberculatum, 390
—— Albus, 684, 586 AXgerita, 640 ;
Panax, 585 sculus, 182, 202, 489, 507, 579
Vilmorinii, 585 Agaric, 394
Acrotheca, 598 Agaricacer, 402, 442
Acrothecium, 609 Key to, 442
Actidium, 164 Agaricales, 395, 397

697

698

Agaricales, Key to, 402

Agaricer, 443, 448

Agaricus, 448, 455

Agave, 89, 248, 552

Agropyron, 306, 320, 389

—— Repens, 262

Agrostis, 321, 380

Agyriella, 538

Agyriellopsis, 534

Albuginacez, 78, 82

Albugo, 78, 79, 82

—— Bliti, 79, 81, 82, 102-116

~——— Candida, 81, 95

—— Ipomeee-pandurane, 81

— Occidentalis, 82

— Portulacezx, 82

—— Tragopogonis, 82

Alder, 130, 203, 248, 264, 274, 419,
428, 545 ;

Aldridgea, 405

Aleurodiscus, 404, 405

Aleyrodes, 194

Alfalfa, 29, 36, 97, 132, 148, 206, 250,
258, 315, 408, 486, 508, 514, 521,
543, 551, 556, 582, 630, 660

Alfilaria, 71, 101

Alga-like Fungi, 3, 65

Allantospora, 589

Allium, 97, 318, 344, 661

Almond, 36, 357, 498, 542, 626

Alnus, 186, 188, 278, 408, 541, 582,
607

Aloe, 493, 560

Alternaria, 260, 261, 616, 621

—— Brassice, 621

—— Cucurbite, 621

—— Dianthii, 622, 622

—— Fasciculata, 624

—— Fici, 624

—— Forsythie, 621

—— Panax, 622

—— Phaseoli, 621

—— Solani, 623, 623, 624

—— Tabacinum, 624

—— Tenuis, 621

—— Trichostoma, 262, 621

INDEX

Alternaria, Viol, 621, 621
—— Vitis, 624
Althea, 386
Alyssum, 178
Alveolaria, 341
Amallospora, 657
Amanita, 398, 450
Amantiopsis, 450
Amarantacee, 303
Amaranthus, 82
Amaryllidacez, 405
Amblyosporium, 572
Amelanchier, 183, 366, 368, 369, 370,
371
Amentacer, 127
Amerospore, 633, 635
— Key to, 636
Amerosporium, 634
—— Cconomicum, 534
Ameebochytrium, 72
Ampelopsis, 181, 238, 484
Ampbhicarpa, 71
Amphispheriacez, 222
Amphispore, 327
Anacardiacez, 127
Ancylistidiales, 66
Andromeda, 398
Anemone, 72, 143, 178, 318, 336, 357,
389
Angélinia, 160
Angiopoma, 515
Anise, 630
Anixia, 189
Annularia, 450
Antennaria, 190, 192
—— Eleophila, 192
— Footi, 192
—— Piniphilum, 192
—— Pityophila, 192
—— Setosa, 192
Anthina, 657
Anthostoma, 277
Anthostomella, 205, 276
Bohiensis, 277
-- — Coffeze, 277
—— Destruens, 277, 277

INDEX

Anthostomella, Sulls, 277

Anthracoderma, 483

Anthracophyllum, 445

Anthrinier, 594

Anthurium, 270, 489, 511, 544, 552

Anthurus, 463

Antromycopsis, 630

Aphanoascus, 167

Aphis, 194

Apiospora, 251

Apiosporium, 190, 191, 192

Brasiliense, 192

Salicinum, 191, 192

Apospheria, 481, 494

Apple, 36, 38, 52, 88, 105, 122, 123,
139, 184, 203, 220, 231, 246, 248,
249, 255, 265, 267, 268, 271, 278,
285, 329, 365, 367, 368, 371, 404,
405, 408, 412, 415, 419, 421, 428,
452, 485, 486, 490, 492, 502, 503,
504, 515, 519, 539, 540, 542, 546,
547, 561, 568, 574, 586, 617, 644,
645, 649

— Rot, 266

—— Twig Canker, 266

Appressoria, 266

Apricot, 139, 357, 486, 491, 560, 569,
604, 610

Aquilegia, 178, 544

Arachnopeziza, 135

Aralia, 168

Arbor Vite, 424, 431

Arbutus, 36

Archangelia, 251

Armillaria, 123, 450, 465

—— Fuscipes, 457

—— Mellea, 230, 410, 411, 456, 457,

458

—— Mucida, 467

Arnica, 176

Aronia, 366, 368

Arrhenatherum, 180

Arrhenia, 443

Arrowroot, 207

Arthrobotrys, 586

Arthrobotryum, 637

699

Artichoke, 41, 591
Arundinaria, 211
Aschersonia, 195, 527
Asciculosporium Take, 211
Asclepias, 188
Ascobolacezx, 133, 134
Ascochyta, 243, 409, 505, 506
ZEsculi, 507

— Aquilegie, 507
—— Armoracie, 506
Aspidistre, 507
— Beticola, 507
Boltshauseri, 506
Brassice, 506
— Caulicola, 508
—— Chrysanthemi, 5607
—— Cookei, 508
— Corticola, 508
—— Digitalis, 507
Dianthi, 507
— Ellisii, 606

—— Fragariz, 507
Graminicola, 508
—— Imperfecta, 508
Tridis, 507

—— Juglandis, 507
—— Lactuce, 507
—— Lycopersici, 508
—— Manihotes, 508
—— Medicaginis, 507
—— Melutispora, 508
—— Nicotianz, 506
Orobi, 507

—— Pallida, 507
—— Parasitica, 506
—— Piniperda, 507
Pisi, 506

—— Polemonii, 507
—— Populicola, 507
Primule, 507
—— Pruni, 507

— Rhei, 506

—— Tremulz, 508
— Vicie, 505

—— Viole, 507
Ascocorticiacese, 125

700

Ascoideacex, 118

Ascomycetes, 64, 113

— Key to, 117

Ascospora, 235, 236

—— Beijerinckii, 236, 560

—— Geographicum, 237

—— Himantia, 236

Padi, 237

Aserce, 463

Ash, 52, 164, 203, 232, 255, 284, 419,
421, 433, 509, 524, 530, 557, 564,
606, 608

Asparagus, 41, 328, 376, 553, 617,
630, 660

Aspedistra, 507, 552

Aspen, 255, 428, 446, 607

Aspergillaces, 165, 166

— Key to, 166

Aspergillales, 114, 124, 164, 167

—— Key to, 165

Aspergillez, 566, 572, 572

—— Key to, 572

Aspergillus, 166, 167, 168, 169, 572,
573

—— Ficuum, 169, 572

—— Fumigatus, 572

—— Pheenicis, 169, 572

Aster, 89, 179, 289, 328, 585, 654

Asterocystis, 68, 69

Radicis, 69

Asterodon, 413

Asteroma, 274, 482, 496

— Codizi, 496

——— Geographicum, 496

—— Padi, 275, 496

—— Punctiforme, 496

Stuhlmanni, 496

Asterophora, 577

Asterosporium, 558

Asterostomella, 481, 531

Asterostomidium, 514

Asterostroma, 406

Asterothyrium, 531

Astragalus, 187

Astrodochilum, 655

Atractiella, 634

INDEX

Atractina, 609
Atractium, 207

Atriplex, 74

Atrocarpus, 273, 541
Attachment organs, 141, 142
Auerswaldia, 216
Aulographum, 163
Aureobasidium, 403, 405
Vitis, 405

Auricula, 611
Auricularia, 393

—— Auricula judie, 393
Auriculariacee, 392

Key to, 392
Auriculariales, 323, 326, 392
Key to, 392
Auriculariex, 393
Autcecious, 329

Avena, 608

Avocado, 512

Azalea, 523

B

Bacillus, 18, 21, 37

—— Ampelopsore, 51, 37
—— Amylovorus, 38, 38
——— Anthracis, 37

—— Apii, 39

—— Araliavorus, 39
—— Aroidex, 39, 39, 42
—— Atrosepticus, 40, 47
—— Avene, 24, 40, 40
—— Betz, 41

—— Brassiceevorus, 27, 41
—— Caratovorus, 39, 40, 41, 42, 46
—— Caulivorus, 27, 43
—— Cepivorus, 43

— Coli, 43

—— Cubonianus, 31, 48
—— Cypripedii, 43

— Dahlia, 43

—— Delphini, 43

—— Elegans, 43

—— Glange, 52

Bacillus, Gossypini, 43

—— Gummis, 43

—— Haria, 44

——— Hyacinthi Septicus, 39, 44
—— Inflatus, 15

Koraiensis, 39

Lactucer, 44

——— Lycopersici, 44

—— Maculicola, 44 ;

—— Megatherium, 13, 15
—— Melangenus, 44

—— Melonis, 44, 44, 45

—— Mori, 21

—— Mycoides, 45

Nicotiana, 45

—— Olea, 45

—— Oleracex,. 39, 42, 46

—— Omnivorus, 42, 46
—— Oncidii, 46

—— Oryze, 46

—— Pestis, 37

—— Phytophthorus, 46
—— Populi, 47

—— Prodigiosus, 21
—— Pseudarabinus, 47
Rosarum, 47
Sacchari, 52
Sesami, 47
Solanacearum, 30, 45, 47, 49
—— Solanicola, 48

—— Solaniperda, 48
Solanisaprus, 47, £8, 48, 49
Sorghi, 49

—— Spongiosus, 49

—— Subtilis, 15, 49
Tabacivorus, 50

Tabificans, 50
Tracheiphilus, 50, 50, 57
—— Typhosus, 19, 37

—— Uve, 37, 61

—— Vulgatus, 51

— Zee, 61

Zinzgiberi, 52

Bacteria, 1, 3, 13, 18

Cell structure, 14

—— Classification, 17

‘

INDEX 701

Bacteria, Constancy of species, 17

—— Entrance to the host plant,
17

—— Group numbers, 20

—— Involution forms, 16

—— Migula, system of, 18

— Mode of increase, 14

—— Modes of spore germination, 16

—— Numerical system of recording,
19

—— Specific characters, 19

—— Spores, 15

—— Three type forms, 13

Bacteriacez, 18, 21

Bacterium, 18, 21

Briosianum, 21

—— Fici, 22

—— Montemartinii, 21

—— Pini, 22

—— Scabigenum, 22

— Teutlium, 22

—— Tuberculosis, 19

Bactridiopsis, 640

Bactridium, 645

Beodromus, 341

Bagnisiella, 216

Bahamia, 11

Balansia, 199, 209, 209, 537

— Claviceps, 209

—— Hypoxylon, 209

Balsam, 423, 436

Bamboo, 209, 211, 215, 310

Banana, 52, 214, 253, 448, 496, 540,
542, 608, 626, 649, 650

Barberry, 333, 380, 385, 546

Barclayella, 341

Barley, 24, 105, 180, 206, 249, 260,
261, 304, 305, 306, 307, 315, 333,
380, 383, 550, 567, 587, 601, 613,
621

Bartalinia, 513

Barya, 198

Basiascum, 553

Basidiella, 636

Basidiobolacez, 107

— Key to, 107

702

Basidiobolus, 107

Basidiomycetes, 64, 298, 475

— Key to, 299

Basidiophora, 83, 89

— Entospora, 89

Basisporium, 599

Baumanniella, 411, 412

Bean, 12, 31, 37, 86, 267, 373, 408,
487, 491, 506, 540, 548, 621, 630, 637

Beccariella, 406

Beech, 106, 134, 152, 162, 203, 249,
415, 421, 427, 429, 430, 433, 436,
440, 444, 445, 509, 544, 545, 547,
606

Beet, 8, 22, 26, 36, 37, 41, 44, 45, 50,
52, 73, 82, 100, 187, 247, 258, 321,
412, 486, 490, 507, 526, 568, 590,
610, 617, 620, 628, 645, 660

Begonia, 43, 168, 544

Belanioscypha, 136

Belonidium, 147

Beloniella, 147

Belonium, 136

Belonopsis, 147

Beltrania, 602

Beniowskia, 639

Berberis, 185, 188, 235, 256, 329, 379,
384

Berlesiella, 283

Bertia, 226

Beta, 374

Betula, 130, 157, 186, 188, 202, 220,
221, 255, 348

Betulacee, 143

Bibliography of introduction, Myxo-
mycetes and Bacteria, 53

-——— Ascomycetes, 288

—— Books, 678

—— Basidiomycetes, 466

—— Fungi Imperfecti, 667

—— Periodicals, 680

—— Phycomycetes, 109

Biologic species and specialization,
174, 260, 262, 332, 380, 611, 640

Birch, 418, 421, 426, 428, 430, 433,
436, 444, 446, 545, 607

INDEX

Bird nest fungi, 395

Bispora, 601

Bizzozeria, 234

Bizzozeriella, 640

Blackberry, 276, 360, 525
Black-leg, 652

Blastomyces, 575
Blastotrichum, 200, 588
Blennoria, 538

Bletia, 552, 645

Blossoms, 107, 108

Bloxamia, 538

Blue grass, 213, 385, 497, 550
Blue-green Alge, 3

Boletacex, 402, 440

—— Key to, 440

Boletiner, 440

Bolinia, 285

Bombardia, 226
Bombardiastrum, 227

Bonia, 406

Bonplandiella, 655

Boraginacezx, 329, 382

Borago, 178

Bornetina, 323

Bostrichonema, 586
Botryodiplodia, 510, 613
Botryospheria, 283, 283, 503
-—— Dothide, 284

Gregaria, 284

—— Ribis, 283

Botryosporium, 571

—— Diffusum, 671

—— Longibrachiatum, 671
—— Pulchrum, 571

Botrytider, 566, 674, 575

—— Key to, 575

Botrytis, 86, 91, 96, 137, 142, 576, 678
—— Cinerea, 140, 578, 678, 581
—— Citricola, 681
——— Depredens, 580
—— Diospyri, 581
—— Douglasii, 141, 581
~——— Fascicularis, 580
—— Galanthina, 141, 581
—— Infestans, ‘681

Botrytis, Longibrachiata, 681
Peoniz, 580

Parasitica, 580

—— Patula, 581

Vulgaris, 140

Boudiera, 115, 116

Bovilla, 224

Bovista, 465

Bovistella, 465

Box, Buxus, 204, 220, 221, 243, 529

656
Box elder, 545
Brachysporium, 609
Brachy-type, 328
Brassica, 69, 178, 390, 617, 629
Bread fruit, 411
Brefeldiacexz, 10
Bremia, 84, 90, 95
Lactuce, 95, 95
Briarea, 572
Briosia, 636
Bromus, 260, 261, 613
Broomella, 199
Brown alge, 3
Brunchorstia, 532
—— Destruens, 151, 532
Bubakia, 340
Buckwheat, 378, 589, 607, 660
Bulb, 141, 661
Bulgaria, 151, 162
— Polymorpha, 152
Bulgariex, 151
Bulgariella, 151
Bullaria, 556
Burillia, 315
Buseella, 570
Butomus, 323
Butternut, 275, 419, 428, 545
Byssocystis, 482

Cc

INDEX

278, 409, 411, 448, 493, 509, 512,
525, 536, 552, 553, 573, 584, 585,

590, 592, 620
Cacospheria, 281
Cactus, 36, 488, 512, 544

Coma, 334, 335, 342, 358, 361, 389,

390
—— Nitens, 360
—— Orchidis, 344
—— Pinitorquum, 344
Calamagrostis, 661
Calcarisporium, 583
Calceolaria, 52
Calendula, 176, 178, 321
Caliciacer, 134, 153
—— Key to, 153
Calicium, 153
Calistephenis, 338
Calla, 39, 488, 560, 631
Calloriexz, 147
Calocasia, 89
Calonectria, 198, 205
—— Bahiensis, 206
—— Cremea, 205, 585
—- Flavida, 205
—— Gigaspora, 206
—— Platani, 205
—— Pyrochroa, 205, 648
Calospheria, 281, 282
—— Princeps, 282, 282
Calospheriex, 281
Calospora, 280, 539
Vanille, 280, 541
Calyptromyces, 104
Camarops, 285
Camarosporium, 516, 617, 517
—— Fissum, 617
— Mori, 517
— Viticola, 517
Camellia, 497, 559, 561
Campanella, 443

Cabbage, 7, 24, 25, 26, 29, 41, 42, 46, Campanula, 101, 333, 340
52, 69, 73, 81, 95, 231, 249, 378, Camphor, 411
408, 484, 491, 492, 530, 544, 619, Camposporium, 609
505, 654 Campsotrichum, 599
Cacao, 130, 204, 205, 206, 232, 277, Camptospheria, 263

704

Camptoum, 598

Canker, 266, 349

Canna, 389

Canteloupe, 620

Cantharellez, 442, 443

Key to, 443

Cantharellus, 443

Caper, 81, 630

Capillaria, 659

Capnodiastrum, 501

Capnodium, 190, 192, 624

—— Citri, 193

—— Citricolum, 193

— Coffex, 192

—— Foedum, 192

—— Guajave, 192

—— Javanicum, 193

—— Meridionale, 193

—— Olea, 193

—— Quercinum, 192

—— Stellatum, 193

—— Taxi, 192

—— Tilie, 192

Capparis, 179

Capronia, 252

Capsule, 14

Caragana, 524, 525

Caravonica, 411

Carduacez, 303

Carex, 303, 376

Carnation, 27, 52, 375, 408, 497, 523,
544, 553, 578, 580, 581, 611, 623,
645, 654

Carpinus, 130, 188, 191, 492, 545

Carrinia, 504

Carrot, 27, 41, 42, 44, 91, 119, 141,
142, 260, 408, 491

Carya, 186, 202, 546

Caryophyllacee, 310, 405

Cassava, 493, 543

Castanea, 140, 186, 188, 558, 562

Castilloa, 411

Castor plant, 89, 654

Casuarina, 571

Catalpa, 168, 178, 186, 188, 256, 426,
489, 619

INDEX

Catastoma, 465

Catenularia, 600

Catinula, 534

Cattleya, 253, 273, 541, 544

Caudospora, 277

Cauliflower, 25, 26,
544

Caulocassia, 100

Cedar, 234

—— incense, 424

Celastrus, 188

Celery, 27, 39, 41, 42, 52, 377, 487,
492, 521, 619, 628

Celidiaceze, 134

Cenangella, 150

Cenangiacez, 134, 150

—— Key to, 150

Cenangium, 150, 161, 162

— Abietis, 151, 532

—— Vitesia, 500

Centaurea, 178, 377

Cephaliophora, 588

Cephalodochium, 641

Cephalosporiex, 566, 570

— Key to, 570

Cephalosporium, 201, 571, 646, 649

Cephalotheca, 166

Cephalothecium, 586

—— Roseum, 586, 586

Cephalotrichum, 598

Ceraplastes, 194

Ceratiomyxacee, 9

Ceratocarpia, 190

Ceratocladium, 630

28, 46, 95,

Ceratophorum, 608, 610

—— Setosum, 610

—— Ulmicolum, 610
Ceratospheria, 232
Ceratostoma, 232
Ceratostomatacer, 222, 232
—— Key to, 232
Ceratostomella, 232

— Pilifera, 233, 233
Cercis, 506, 524
Cercospora, 243, 257, 478, 625
—— Acerina, 632

INDEX 705

Cercospora, Acerosum, 630 Cercospora, Roesleri, 626

—— Althzina, 630 —— Rosicola, 630, 630

—— Angreci, 631 —— Rubi, 626

~—— Angulata, 245, 626 —— Sacchari, 630

—— Apii, 628, 628 —— Sequoiz, 632

~——— Ariminensis, 630 —— Sordida, 631

—— Armoracie, 629 —— Thee, 630
Asparagi, 630 —— Unicolor, 631

-——— Beticola, 628, 628 —— Vagine, 630

— Bloxami, 629 —— Vigne, 630

—— Bolleana, 626 —— Viole, 630
Brunkii, 631 —— Viticola, 626

——— Capparidis, 630 Cercosporella, 592

—— Cerasella, 245, 625 —— Albo-maculans, 592
Cercidicola, 631 —— Inconspicuus, 592

—— Cheiranthi, 631 — Narcissi, 592
Circumscissa, 625 —— Pastinace, 592
Citrullina, 629 —— Persice, 592

—— Concors, 626, 626 Cereal, 248, 250, 385, 491, 600

—— Cruenta, 629 Cereus, 499, 529

—— Cucurbite, 629 Cerocorticium, 405

—— Flagelliformis, 629 Cerotelium, 341

—— Fumosa, 626 Cesatiella, 198
Gossypina, 248, 625 Ceuthospora, 483, 600

—— Halstedii, 632 —— Cattleya, 500, 500

—— Hypophylla, 631 —— Coffeicola, 500

—— Kellermanii, 630 Chenotheca, 153
Kopkei, 630 Cheetocladiacex, 103

—— Longipes, 630 Cheetoconidium, 577

—- Malkoffi, 630 Chetodiplodia, 510

—— Malvarum, 630 — Vanille, 610

—— Medicaginis, 630 Chetomella, 501

—— Melonis, 629 Cheetomiacer, 222

—— Microsora, 631 Chetopeltis, 532

—— Moricola, 626 Chzetophoma, 191, 482, 495

—— Musz, 626 —— Glumarun, 495

—— Neriella, 631 Chetospermum, 641

—— Nicotianz, 627, 627 Cheetospheria, 226

—— Odontoglossi, 631 Cheetostroma, 201, 655, 656

—— Omphacodes, 631 —— Buxi, 656

—— Oryza, 626 —— Clivie, 656

—— Personata, 629 Chetozythia, 527

—— Phlogina, 631 Chalara paradoxa, 596

—— Raciborskii, 627 Chalariex, 595

—— Resede, 631 Chamecyparis, 370, 416

—— Richardiaecola, 631 Characex, 3

706

Charrinia, 262, 263
Cheiranthus, 619, 631
Chenopodiacez, 96
Chenopodium, 74
Cherry, 49, 129, 138, 184, 219, 237,
245, 255, 268, 275, 282, 357, 376,
419, 507, 512, 520, 560, 562, 604,
606, 625, 649
Cherry laurel, 410
Chess, 550
Chestnut, 36, 101, 209, 281, 321, 419,
420, 439, 442, 445, 489, 498, 499,
509, 524, 560, 597
Chicory, 490
China berry, 202
Chitonia, 448
Chitonospora, 251
Chlamydobacteriacem, 19
Chlamydospores, 60
Chlorophycez, 3
Chlorosplenium, 135, 144
—— ruginosum, 143, 144
Choanephora, 107
Americana, 107
—— Cucurbitarum, 107
—— Infundibulifera, 107
Choanephoracee, 103, 106, 107
Chondromyces, 634
Chromosporium, 566
Chrysanthemum, 36, 105, 386, 389,
mir 392, 409, 488, 492, 507, 522, 563,
569
hrysomyxa, 341, 350
—— Abietis, 350
Chrysophlyctis Endobiotica, 70, 71
Chrysopsora, 336
Chytridiales, 60, 65, 66, 101
— Key to, 67
Ciboria, 135
Cicer, 179
Cichorium, 178, 378
Cicinnobella, 501
Cicinnobolus, 174, 482, 494
Cienkowskia, 11
Ciliciopodium, 634
Ciliofusarium, 657

INDEX

Ciliospora, 527

Cineraria, 339

Cinnamon, 390, 398, 487

Cintractia, 302, 310

Cionothrix, 342

Circinella, 105

Cissis, 303

Citron, Citrus Fruits, 44, 45, 193,
194, 249, 490, 491, 504, 512, 520,
540, 541, 548, 559, 574, 581, 604,
605, 626, 649

Citysus, 100

Cladobotyrum, 583

Cladochytriacee, 67, 72

— Key to, 72

Cladochytrium, 72

—— Brassice, 73

— Cespitus, 73

—— Graminis, 73

—— Mori, 73

— Tenue, 73

—— Violx, 73

—— Viticolum, 73

Cladoderris, 406

Cladospheria, 263

Cladosporium, 217, 219, 257, 602,
603, 617

—— Bigarardia, 605

—— Brunnec-atrum, 606

—— Carpophilum, 604, 604

— Citri, 604

—— Condylonema, 605

— Cucumerinum, 603, 604

—— Elegans, 604

— Epiphyllum, 606

—— Fasciculare, 260, 603

—— Fulvum, 604, 605

Graminum, 605

—— Herbarumn, 248, 603

—— Citricolum, 604

—— Hypophyllum, 606

— Javanicum, 606

—— Juglandis, 606

—— Macrocarpum, 605

—— Orchidis, 605

—— Oryze, 605

INDEX

Cladosporium, Oxycocci, 606

—— Peonie, 606

— Pisi, 605

—— Scabies, 606

—— Scribnerianum, 606

—— Sicophilum, 604

—— Tuberum, 606

—— Zee, 606

Cladosterigma, 634

Cladotrichum, 601

Clanostachys theobrome, 206

Clasterosporium, 608, 609

—— Amygdalearum, 610

—— Carpophilum, 560, 610

— Glomerulosum, 610

—— Putrefaciens, 610

Clathracezr, 4€2, 463

— Key to, 463

Clathrus, 464

Claudopus, 449

Clautriavia, 462

Clavaria, 412

Clavariaces, 402, 412

Key to, 412

Claviceps, 199, 211, 211, 213, 215, 643

Microcephala, 213

—— Paspali, 213

— Purpurea, 212, 643

— Rolfsii, 213

Clavicipitez, 196, 197

—— Key to, 199

Cleistotheca, 190

Clematis, 43, 178, 179, 390, 492, 544,
563

Clinoconidium, 640

Clithris, 156, 157, 157

—— Aureus, 157

—— Juniperus, 157

—— Quercina, 157

Clitocybe, 450, 457, 459, 569

—— Parasitica, 458

Clitopilus, 450

Clivia, 656

Clonostachys, 584

Clostridium Butyricum, 13

Persicze tuberculosis, 63

707

Clove, 415

Clover, 71, 74, 97, 148, 187, 206, 220,
221, 258, 373, 374, 494, 548, 551,
569, 582, 593, 606, 619, 630

Clusia, 560

Clypeospheria, 276

Clypeospheriacex, 223, 276

— Key to, 276

Coccacee, 18, 21

Cocci, 13

Coccomyces, 156, 563

Cocconia, 156

Coccophacidium, 156

Coccospora, 566

Coccosporella, 566

Coccosporium, 616

Cocoa, 88

Cocoanut, 43, 191, 193, 433, 512,
513

Codiaeum, 496, 544

Coémansia, 583

Ccemansiella, 571

Coffee, 168, 170, 192, 193, 195, 205,
207, 249, 250, 277, 356, 409, 415,
486, 500, 504, 512, 515, 525, 543,
553, 583, 591, 597, 635, 643, 660

Colchicum, 375, 563

Coleosporiacer, 335

— Key to, 336

Coleosporium, 326, 333, 336, 390, 391

Campanula, 339

— Ipomee, 337

—— Pini, 339

Senecionis, 338, 338

—— Solidaginis, 337, 337

Coleroa, 226, 227, 658

—— Chetomium, 227, 227

Sacchari, 227

Collacystis, 527

Collard, 25, 95, 619

Colletotrichum, 147, 264, 267, 268,
538, 539, 540, 547

—— Agaves, 552

— Althezx, 552

—— Ampelinum, 549

—— Anthurii, 552

708

Colletotrichum, Antirrhini, 563

—— Bletie, 552

—— Brachytrichum, 553

— Camellie, 553

—— Garica, 649, 549

—— Cereale, 550, 550

—— Cincta, 269, 547

—— Coffeanum, 653

Cradwickii, 553

—— Cyclamene, 553

—— Dracene, 553

—— Elastice, 552

— Falcatum, 549

—— Gleeosporioides, 549

—— Gossypii, 267, 272, 547

—— Hedericola, 553

—— Hever, 553

—— Incarnatum, 553

—— Kentiz, 552

—— Lagenarium, 548

— Lineola, 550

—— Lindemuthianun, 267, 543, 647,
548

—— Luxificum, 552

—— Macrosporum, 653

—— Malvarum, 552

—— Nigrum, 561

—— Oligochetum, 548

—— Omnivorum, 552

—— Phomoides, 551

—— Piperitum, 551

— Pollaccii, 553

—— Primule, 552

—— Rubicolum, 270, 547

— Schizanthi, 552

—— Spinacie, 561

—— Theobrome, 553

—— Theobromicolum, 553

—— Trifolii, 551

—— Viole-tricoloris, 552

Collodochium, 640

Collonema, 517

Collybia, 450, 458

—— Velutipes, 458, 460

Columbine, 507

Colus, 464

INDEX

Colutea, 187

Completoria, 107

—— Complens, 108

Composit, 82, 92, 95, 178, 386

Comptonia, 352

Conidiobolus, 107

Conifers, 132, 145, 159, 161, 162, 203,
229, 235, 350, 390, 417, 418, 423,
431, 436, 452, 512, 547, 559, 579,
654

Coniocybe, 153

—— Pallida, 153

Coniophora, 405

Coniosporie, 594, 595

—— Key to, 595

Coniosporium, 595, 595

—— Filicinum, 595

Onobrychidis, 595

Coniothecium, 615

Chomatosporum, 617

Coniothyrium, 245, 257, 501, 503

—— Anomale, 504

—— Brevisporum, 504

—— Coffer, 504

—— Concentricum, 503

—— Diplodiella, 263, 504, 504

—— Fuckelii, 257, 258, 508

—— Hellebori, 605

—— Japonicum, 504

—— Megalospora, 228

—— Melastorum, 503

—— Pyriana, 503

— Scabrum, 604

—— Tumefaciens, 503

—— Vagabundum, 604

—— Wernsdorffie, 505

Conjugate, 3

Conjugate division, 321, 831, 332

Convallaria, 494

Convolvulacee, 82

Coprines, 442

Corallodendron, 633

Corallomyces, 199 F

Cordana, 602

Cordieritidacese, 134

Cordyceps, 199

INDEX

Coremium, 230, 634, 635, 635

Coreopsis, 176

Corethropsis, 571

Coronella, 570

Corn, 34, 52, 90, 101, 308, 310, 312,
329, 408, 511, 512, 606, 613, 614,
650

Cornularia, 517

Cornus, 188, 191, 279, 524

Coronophora, 281

Corpyha, 560

Corticium, 403, 405, 406, 409

—— Chrysanthemi, 409

—— Comedens, 409

—— Dendriticum, 409

—— Javanicum, 409

—— Latum, 408

—— Lilacino-fuscum, 409

—— Vagum-solani, 404, 406, 407,
660

Zimmermannii, 409

Cortinarius, 449

Corydalis, 344

Corylus, 188, 408, 530, 545, 557

Corymbomyces, 583, 584, 584

—— Albus, 205, 584

Coryneliacez, 222

Corynespora, 629

Corynetes, 131

Coryneum, 558, 560, 564, 658

Beijerinckii, 236, 237, 560, 561

—— Camellie, 561

—— Folliicolum, 561

—— Juniperinum, 560, 658

—— Modonia, 560

—— Mori, 561

Cosmonectria, 201

Cosmos, 493

Costinellus, 450

Cotton, 29, 36, 43, 249, 267, 272, 303,
361, 408, 411, 486, 492, 547, 589,
619, 625, 650, 651

Cotton-wood, 437

Cotoneaster, 366

Couturea, 515

Cowpea, 187, 487. 521, 535, 651

709

Cranberry, 71, 140, 225, 231, 267, 277,
397, 486, 495, 500, 520, 525, 529,
536, 543, 559, 606, 614

Crandallia, 5382

Crategus, 130, 183, 188, 255, 366,
367, 368, 569

Craterellus, 406

Craterium, 12

Creonectriex, 196

Cribrariacez, 9

Crocicreas, 481

Crocus, 121, 143

Cronartium, 341, 360, 351, 390, 391

—— Asclepiadeum, 352

— Comptonie, 352, 362

—— Quercus, 352, 390

—— Ribicola, 360

Crotalaria, 408

Crotonocarpia, 226

Crown gall, 12

Crucifer, 6, 25, 41, 43, 69, 81, 95, 616,
619, 621

Crumenula, 150

Cryptocoryneum, 608

Cryptoderis, 263

Cryptomela, 553

Cryptomyces, 156, 168

—— Maximus, 158

Cryptospora, 279

Cryptosporella, 279, 280

—— Anomala, 280

—— Viticola, 280, 282, 498

Cryptosporium, 562, 564

—— Leptostromiforme, 564

Minimum, 564

Cryptostictis, 515, 616, 516

— Caudata, 516

Cynosbati, 516

Cucumber, 44, 45, 46, 51, 52, 76, 95,
141, 247, 404, 487, 543, 548, 569,
604, 606, 608, 615,:617, 629,
652

Cucumis, 178

Cucurb, 6, 51, 94, 95, 107, 178, 179,
487, 509, 521, 539, 548, 651

Cucurbita, 178

710

Cucurbitaria, 234
—— Berberdis, 235, 235
—— Elongata, 235
—— Laburni, 235
—— Picer, 235
—— Pityophila, 235
—— Sorbi, 235
Cucurbitariacer, 222, 234
—— Key to, 234
Cudoniezx, 131
Cuphea, 187
Cupressus, 369
Currant, 92, 148, 155, 203, 207, 284,
351, 433, 499, 500, 519, 542, 626
Currya, 216
Curryella, 216
Cuttings, 644
Cyanocephalium, 198
Cyanophycer, 3
Cyanospora, 232, 233
—— Albicedre, 233, 233
Cyathicula, 136
Cycad, 248, 516
Cyclamen, 52, 168, 268, 488, 492, 522,
553, 579

Cycloconium, 601, 602, 603
—— Oleaginum, 603
Cyclomyces, 417
Cyclostomella, 163
Cydonia, 366, 368
Cylindrium, 568
Cylindrocephalum, 571
Cylindrocladium, 586
Cylindrocolla, 641
Cylindrodendrum, 577
Cylindrophora, 576
Cylindrosporium, 243, 562, 562
—— Castanicolum, 249, 562
—— Cercosporoides, 564
~——— Chrysanthemi, 563
—— Clematidis, 563

—— Jackmani, 563
—— Colchici, 563
— Humuli, 563
-— Inconspicuum, 563
— Mori, 249, 525, 562

INDEX

Cylindrosporium, Orni, 564
—— Padi, 562, 562, 563
— Pomi, 563, 563

—— Quercus, 564

—— Saccharinum, 563
—— Tubeufianum, 563
—— Viridis, 564
Cylindrotrichum, 575
Cymbridium, 547
Cynachum, 352

Cynodon, 221

Cyperacee, 303

Cyperus, 89, 303, 408
Cyphella, 406
Cystophora, 598

Cytisus, 235, 253, 375, 610
Cytodiplospora, 505
Cytoplea, 501

Cytospora, 209, 279, 483, 499, 499
—— Acerina, 499

—— Ceratophora, 499
—— Palmarum, 499

—— Rubescens, 278

—— Sacchari, 499
Cytosporella, 483, 498
Cerei, 499

— Citri, 499

— Damnosa, 499
Persicz, 499
Cytosporina, 518, 526, 526
— Ribis, 526
Cytosporium, 516
Cystothyrium, 531
Cystotricha, 505
Cyttariacee, 134

D

Dacromycetales, 395, 396
Dacryodochium, 641
Dacrymycella, 640
Dactylaria, 588
Dactylella, 588
Dactylium, 588
Dactylopias, 194
Dactylosporium, 616

Dadap, 411

Deedalea, 417, 489

—— Quercina, 439, 440
Dahlia, 43, 178, 492, 645
Daisy, 36

Daldinia, 285

Dammara, 489

Damping Off, 77
Dandelion, 71, 119, 378, 590
Daphne, 544

Darluca, 335, 505
Darwinella, 216
Dasyscypha, 135, 144, 144
—— Abietis, 145
Calyciformis, 145
—— Resinaria, 145

—— Subtilissima, 145
Willkommii, 144, 145
Date, 169, 310

Datura, 48

Daucus, 178

Deconica, 449

Delacourea, 252

Delitschia, 224
Delphinium, 178, 321
Dematiacee, 565, 594

Key to, 594

—— Amerospore, 594, 599
Key to, 599

—— Dictyospore, 594, 615
Key to, 615
Didymospore, 599, 601
— Key to, 601

—— Heliocospore, 594
—— Phragmospore, 594, 608
Key to, 608

—— Saturospore, 594
Scolecospore, 594, 625
Key to, 625
Dematium, 217, 600
Prunastri, 495
Dematophora, 230

— Glomerata, 201
Necatrix, 230, 231
Dendrodochium, 640, 643
Lycopersici, 643

INDEX 711

Dendrographium, 637

Dendrophagus Globosus, 12

Dendrophoma, 481, 494, 494

—— Convallarie, 494

—— Marconii, 494

—— Valsispora, 494

Dendrostilbella, 633

Dendryphiez, 609, 615

Dendryphium, 615

—— Cornosum, 615

Dermatea, 151, 162, 152

—— Acerina, 152

—— Carpinea, 152

—— Cinnamomea, 152

—— Prunastri, 152

Dermatezx, 150

Desmazierella, 135

Desmodium, 187, 188

Dewberry, 648

Diachnz, 11

Diachora, 216, 217

— Onobrychidis, 217

Dialonectria, 201, 205

Dianthus, 101, 312, 328, 375, 387,
488, 507, 619, 654

Diaphanium, 639

Diaporthe, 277, 278, 279, 490, 498

—— Albocarnis, 279

—— Ambigua, 279, 490

—— Parasitica, 209

—— Sarmentella, 279, 490

—— Strumella, 279, 499

—— Taleola, 279

Diatomez, 3

Diatrypacem, 223, 281

—— Key to, 281

Diatrypezx, 281

Dichenacee, 160, 162

Dichea, 162

—— Faginea, 162

— Quercina, 162, 163

Dicheirinia, 353

Dichlena, 527

Dichomera, 516

Dicoccum, 601, 602

Rose, 602

712 INDEX

Dicotyledones, 203 Diplocladium, 200, 586, 653
Dictyophora, 462, 463 Diplococcium, 602, 603
Dictyospore, 633 —— Conjunctum, 603
Dictyosporium, 615 Diplodia, 243, 510, 511, 611, 51/1,
Dictyuchus, 75 513

—— Monosporus, 75 —— Aurantii, 512
Dicyma, 598 — Cacaoicola, 512
Diderma, 10 —— Cerasorum, 512
Didymaria, 586, 587, 587 —— Citricola, 512
Didymella, 251, 255, 256 —— Coffeicola, 512
—— Citri, 256 —— Destruens, 512
Didymiacez, 10 —— Epicocos, 512

— Key to, 10 —— Gongrogena, 512
Didymium, 9, 10 —— Heteroclita, 5612
—— Dedalium, 10 —— Macrospora, 611
Didymocheta, 505 — Mori, 512
Didymocladium, 586 —— Natalensis, 512
Didymopsis, 586 —— Opuntie, 512
Didymopsora, 342 — Oryzezx, 512
Didymospheria, 251, 256, 256 —— Perseana, 512

— Catalpe, 256 —— Pinea, 512

—— Epidermidis, 266 —— Rapax, 512

— Populina, 256 —— Sapinea, 612

—— Spheroides, 256 —— Zee, 611
Didymospore, 633 Diplodiella, 510, 512, 512
Didymosporium, 556, 556 — Oryza, 512

—— Salicinum, 656 Diplodina, 247, 505, 509, 509
Dieback, 278 —— Castanezx, 509, 509
Diervilla, 178 —— Citrullina, 247, 509
Dietelia, 342 — Corticola, 509
Digitalis, 100, 488, 507 — Parasitica, 509
Digitaria, 591 —— Salicina, 509

Dill, 377 Diplodiopsis, 510
Dilophia, 251, 257, 525, 590 Diplophysa, 73

—— Graminis, 256, 257, 525 Diplorhinotrichum, 585
Dilophospora, 518, 525, 525 Diplosporium, 586

— Graminis, 257, 525 Dipsacus, 176, 178
Dimargaris, 572 Discella, 536, 536
Dimerosporium, 189, 191 —— Cacaoicola, 536
— Collinsii, 191 Discocyphella, 406

—— Mangiferum, 191 Discomycetes, 116, 117, 123, 159
—— Pulchrun, 191, 191, 625 Discomycopsella, 531
Dinemasporium, 534, 535, 536 Discomycopsis, 501

— Oryze, 535 Discosia, 531
Dinoflagellates, 3 —— Pini, 531

Diospyrus, 183 Discula, 534, 535, 635

INDEX

Discula, Platani, 274, 535
Dispira, 572°
Ditopella, 263, 264
—— Ditopa, 264
Fusispora, 264
Doassansia, 301, 315, 322, 322
Gossypii, 323
Niesslii, 322
Dogwood, 158, 203
Dolichos, 373
Doratomyces, 571
Doscocolla, 645
Dothichiza, 534, 535, 535
—— Ferruginosa, 152
—— Populea, 535
Dothidiaces, 215
—— Key to, 216
Dothichlce, 210
—— Aristide, 210
—— Atramentosa, 210
Dothidea, 216, 218, 220
— Noxia, 220
— Rosa», 220
Dothidella, 219, 221
— Betulina, 221
—— Thoracella, 221
—— Ulmi, 221
Dothidiacex, 215
—— Key to, 216
Dothidiales, 124, 195, 215
Dothiochle, 199
Dothiopsis, 483
Dothiora, 155, 156
Virgultorum, 157
Dothiorella, 284, 483, 499
Mori, 499, 499
—— Populi, 499
—— Ribis, 499
Dothiorellina, 483, 499
— Tankoffii, 499
Double Blossom, 648
Downy Mildew, 82
Dracena, 270, 487, 489, 497, 503,
553
Dracenacee, 303
Drepanospora, 609

713

Drupe, 139, 236, 237, 410, 486
Durio, 221

Dusiella, 211

Dyctilium, 200

E

Earlea spiciosum, 359

Eccilia, 450

Echinobotryesx, 594

Echinodontium, 414, 415

—— Tinctorium, 415

Echinodorus, 315

Echinodothis, 199, 211

Tuberiformis, 211

Ectostroma, 657

Ectrogella, 68

Egg plant, 37, 42, 47, 204, 268, 408,
487, 491, 508, 539, 540, 580, 617

Elaphomycetacez, 165

Elder, 185, 393

Eleutheromyces, 197

Elm, 71, 127, 130, 182, 221, 249, 260,
393, 421, 430, 437, 455, 484, 489,
503, 530, 544, 557, 606

Emericella, 167

Emmer, 206, 550

Enchnoa, 262

Endive, 377

Endobotrya, 516

Endoconidium, 146, 639, 641, 641

Temulentum, 642

Endogone, 118

Endomyces, 122

— Decipiens, 123

—— Mali, 122, 123, 123

Parasitica, 123

Endomycetacex, 120, 122, 165

Key to, 122

Endophyllum, 342, 363

—— Sempervivi, 353

Endothia, 283

Entoloma, 450

Entomogenous fungi, 194

Entomophthoracee, 107

714

Entomophthorales, 66, 102, 107

—— Key to, 107

Entomosporium, 243, 531, 532, 632

—— Maculatum, 149, 532

—— Mespili, 150, 532

— Thumenii, 532

Entyloma, 314, 320

—— Australe, 322

—— Betiphilum, 321

— Calendule, 321

—— Crastophilum, 321

—— Ellisii, 321, 321

—— Fuscum, 322

—— Irregulare, 321

—— Lephroideum, 321

—— Polysporum, 321

Enzymes, 2

Ephelis, 209, 537

Epichle, 199, 210, 210, 211

—— Typhina, 210, 643

Epicoccum, 655, 656, 656

—— Hyolopes, 656

Epidochiopsis, 641

Epidochium, 655, 656

—— Oryze, 656 ~

Epilobium, 347

Epochnium, 601

Eremascus, 122

Ergot, 213

Erica, 617

Ericacez, 143, 159, 186, 397

Erigeron, 89

Erinella, 136

Eriobotrys, 607

Eriocaulacez, 303

Eriopeziza, 135

Eriospora, 518

Eriosporangium, 355

Eriosporina, 515

Enriothyrium, 528

Erysiphacee, 117, 166, 170, 171, 176,
192

—— Key to, 174

Erysiphales, 332, 475, 494, 569

Erysiphe, 117, 143, 166, 172, 178,
175, 177

INDEX

Erysiphe, Cichoracearum, 174, 178,
178, 569
Graminis, 171, 179, 179, 569
—— Liriodendri, 178
—— Martii, 178
—— Polygoni, 177, 177, 178, 187
—— Taurica, 179
—— Umbelliferarum, 178
Erysiphee, 260
Euascomycetes, 117, 123
— Key to, 123
Eubacteriales, 18
Eubasidii, 299
Eubasidiomycetes, 394
—— Key to, 394
Eucalyptus, 310, 560
Eumyecetes, 1, 3, 59
—— Key to, 64
Eunectria, 201, 202
Euphorbia, 187, 329, 330, 372, 374,
375
Eurotiopsis, 167, 527
Eusclerotinia, 137
Eutaphrina, 127
Eutypa, 278
Eu-type, 328
Excipula, 534
Excipulacex, 479, 533
Key to, 533
—— Hyalodidyme, 533, 537
—— Key to, 536
—— Hyalophragmie, 533, 536
— Hyalospore, 533
—— Key to, 534
—— Pheophragmie, 533, 536
— Phezospore, 533
—— Scolecospore, 533, 536
Key to, 536 .
Excipularia, 657
Exoascacee, 125
—— Key to, 126
Exoascales, 396
Exoascus, 125, 127
Exobasidiales, 125, 395, 396
Key to, 396
Exobasidium, 396

INDEX

Exobasidium, Andromeda, 396, 397
Azalex, 398

—— Cinnamomi, 398

—— Japonicum, 398

—— Lauri, 398

—— Oxycocci, 397

— Peckii, 398

~— Rhododendri, 398
Vaccinii, 397

—— Vexans, 397

Vitis, 398
Exosporina, 656, 656
Laricis, 656
Exosporium, 227, 657, 668
Juniperinum, 560, 658
—— Laricinum, 658

—— Palmivorun, 658, 658
Preslii, 658

—— Rubinus, 227

Tilie, 658

Fabacez, 303

Fabreea, 147, 243

— Malculata, 149, 149, 532

Mespili, 150, 532

Fagopyrum, 178

Fagus, 188, 545

Farlowiella, 160

Favolus, 417, 439

Australis, 438

Europzus, 438, 439

Fenestrella, 278

Ferments, organic, 2

Fern, 77, 108, 126, 250, 581, 595

Festuca, 180, 310, 383, 635

Ficaria, 375

Ficus, 205, 249, 267, 278, 533, 544,
552

Fig, 22, 169, 310, 346, 408, 549, 564,
572, 573, 604, 624, 626, 643

Filbert, 280

Fimbrystylis, 303

Fir, 132, 145, 162, 192, 203, 276,
320, 347, 349, 418, 424, 431, 434,

715

438, 440, 465, 490, 492, 493, 507,
568, 581, 657
Fission, 14
Fistulina, 440, 441
Hepatica, 441, 442
Fistulines, 440
Flagella, 14
Flammula, 449, 452
—— Alnicola, 452
—— Penetrans, 452
Spumosa, 452
Flax, 69, 343, 653
Floccomutinus, 462
Fodder, 599
Fomes, 417, 418, 663
—— Annosus, 431
—— Applanatus, 433, 436
—— Australis, 437
— Carneus, 430
—— Everhartii, 430
—— Fomentarius, 426, 429, 429
—— Fraxinophilus, 433
—— Fulvus, 433
— Fulvus olezx, 433
=— Hartigii, 434
—— Igniarius, 401, 428, 428, 429, 433,
434
—— Juniperinus, 431
— Laricis, 432
—— Lucidus, 433
—— Marmoratus, 434
—— Nigricans, 433
—— Pinicola, 435, 436
—— Ribis, 432
—— Robinie, 434
Semitosus, 437
—— Sessilis, 435
—— Ulmarius, 437
Forget-me-not, 101
Form Genera, 476
Forsythia, 621
Fox Tail, 90
Fracchiza, 234
Fragaria, 176, 244
Fraxinus, 188
Fruits, 106

716

Fuckelia, 152, 155, 483, 600
—— Ribis, 600

Fuligo, 11, 12, 200
Fumago, 191, 616, 624
— Camellie, 194, 625
Fungi, 1, 3

—— Classification, 64

—— Imperfecti, 64, 475
Key to, 479

—— Slime. See Mycomycetes.

—— True, 1, 2, 59
Funkia, 489
Fusariella, 608

Fusarium, 201, 204, 205, 475, 571,

645, 646
—— Acuminatum, 652
—— “ruginosum, 652
—— Affine, 652
—— Aurantiacum, 651
—— Avenaceum, 206
—— Blasticola, 654
—— Brassice, 654
—— Ceeruleum, 647, 648, 652
— Commutatum, 648, 652
—— Cubense, 649
—— Cucurbitarie, 662
— Culmorun, 206, 649, 649
—— Decemceellulare, 654
—— Dianthi, 654
—— Didymium, 647, 652
—— Diplosporum, 652
—— Discolor, 648

—— Sulphureum, 648

—— Erubescens, 653
—— Falcatum, 648
—— Gemmiperda, 649
—— Gibbosum, 648
—— Heterosporum, 206
—— Hordei, 206
—— Incarnatum, 664
—— Limonis, 649
—— Lini, 653, 653
—— Lycopersici, 653
—— Martii, 648
—— Metachroum, 648
—— Moniliforme, 650

INDEX

Fusarium, Nivale, 205
—— Niveum, 651

—— Oxysporum, 648, 661, 652, 653

—— Pelargonii, 654

—— Pestis, 652

—— Pini, 664

—— Platani, 205, 648

—— Putrefaciens, 649

—— Rhizogenum, 649

—— Ricini, 654

—— Roseolum, 652

—— Roseum-lupini-alba, 652
—— Rubi, 648

—— Rubiginosum, 647, 648
—— Solani, 204, 585, 648, 652
—— Subulatum, 648

— Tabacivorum, 664

—— Theobrome, 648, 654
—— Udum, 661

—— Vasinfectum, 205, 650, 660, 651

—— Pisi, 648, 661
—— Tracheiphila, 651
—— Violaceum, 652
— Viole, 664
— Wilkommii, 648
Fusella, 595
Fusicladium, 253, 602, 606
—— Betule, 255, 607
—— Cerasi, 255, 606
—— Dendriticum, 253, 255, 607
Depressum, 607
— Destruens, 607
—— Effusum, 607
— Eriobotryz, 607
—— Fagopyri, 607
—— Fraxini, 255, 606
— Lini, 607
—— Orbiculatum, 255, 607
—— Pirinum, 253, 607
Saliciperdum, 606
Tremule, 255, 607
—— Vanille, 607
Fusicoccum, 274, 280, 483, 498
—— Amygdali, 498
—— Bulgarium, 498
—— Perniciosum, 281, 498

INDEX

Fusicoccum, Veronense, 275, 498
Viticolum, 498, 498
Fusicolla, 639

Fusidium, 201, 203, 567, 568
—— Candidum, 568
Fusisporium solani, 648

Fusoma, 588, 590

Parasiticum, 590

G

Galera, 449
Gallowaya, 339
Gamospora, 517
Gamosporella, 483
Gaphiothecium, 630
Garden-pea, 408
Garlic, 97
Gasteromycetes, 395
Gaylussacia, 397
Geaster, 465
Gelatinosporium, 518
Geminispora, 263
Gemme, 60
Gentiana, 352, 389
Geoglossacer, 131, 154
—— Key to, 131
Geoglosser, 131
Geoglossum, 131
Geotrichum, 568
Geranium, 52, 315, 390, 591, 603, 631,
654
Gherkin, 247
Gibbellina, 251, 266
Cerealis, 256
Gibellula, 634
Gibbera, 234
—— Vaccinii, 234, 235
Gibberella, 198, 206, 646
—— Cerealis, 207
—— Moricola, 207
—— Saubinettii, 206, 206
Gibberidea, 234
Gibelia, 283
Ginger, 77

Ginkgo, 267

Ginseng, 39, 88, 141, 496, 559, 585
622, 651

Giulia, 532

Gladiolus, 250, 318, 320, 389

Gleditschia, 267

Glenospora, 599

Gliobotrys, 570

Gliocephalus, 570

Gliocladium, 574

—— Agaricinum, 574

Gliodcladium, 572, 574

Globaria, 465

Gleeocephala, 412

Gleeoporus, 417

Gleeosphera, 583

Gleeosporium, 147, 252, 264, 266, 267
269, 274, 475, 478, 538, 539, 547

—— Affine, 544

—— Alborubrum, 644

—— Allescheri, 545

—— Alneum, 546 |

—— Ampelophagum, 541

—— Amygdalinum, 642

—— Anthuriophilum, 544

—— Apocryptum, 545

—— Aquiligie, 544

—— Atrocarpi, 273, 541

Begoniz, 644

—— Berberidis, 546

— Betularum, 546

—— Betulinum, 545

Beyrodtii, 544

— Bicolor, 541

Bidgoodii, 644

—— Bruneun, 544

—— Cactorum, 644

—— Canadense, 546

—— Carpini, 545

— Carye, 545

—— Cattleyx, 544

Caulivorum, 543

—— Cinctum, 541

—— Cingulatum, 268, 641

—— Citri, 541

— Clematidis, 544

717

718 INDEX

Glceosporium, Coffeanum, 543 Gloeosporium, Pestis, 543
—— Concentricum, 544 —— Piperatum, 269, 641
—— Coryli, 545 —— Platani, 274
—— Crotonis, 544 —— Psidii, 271, 541
—— Curvatum, 542 — Quercinum, 545
—— Cydoniz, 542 — Rhododendri, 544
—— Cylindrospermum, 641 —— Ribis, 148, 541
-—— Cytisi, 544 _ 7 — Rose, 544
—— Depressum, 541 — Rufomaculans, 265, 255, 267,
—— Dianthi, 544 639
—— Diospyri, 542 —— Saccharini, 546
—— Elastice, 267, 544 —— Salicis, 148, 541
—— Euphobiz, 644 —— Soraurianum, 544
—— Fagi, 645 —— Spegazzinii, 641
—— Fagicolum, 544 —— Stanhopeicola, 544

Fragarie, 542 —— Tamarindi, 546
——— Fructigenum, 267, 539 —— Thea, 544
—— Helicis, 544 —— Sinensis, 544
—— Hendersonii, 541 —— Tiliaceum, 545
— Inconspicuum, 544 —— Tiliz, 546
—— Intermedium, 641 —— Tremule, 646
—— Juglandis, 545 — Trifolii, 543
—— Kawakami, 545 —— Umbrinellum, 544
— Lelie, 544 —— Vanille, 280, 641
— Laticolor, 267, 539 —— Variabile, 542
—— Lagenarium, 643 —— Venetum, 542
—— Macropus, 253, 641 —— Versicolor, 267, 539
—— Malicorticis, 493, 542, 642 —— Viole, 544
—— Mangifere, 543 Gleesporiella, 555
—— Manihotis, 543 Glomerella, 263, 264, 475, 539, 547
—— Medicaginis, 543 —— Atrocarpi, 273, 541
—— Melengonea, 539 — Caetorum, 265
-—— Mezerei, 544 —— Cincta, 269, 270, 541, 547
—— Minus, 643 —— Cingulata, 268, 541
—— Morianum, 543 —— Gossypii, 267, 271, 272, 273,
—— Musarum, 542 547

—— Importatum, 542 —— Piperata, 269, 270, 271, 541
—— Mpyrtilli, 643 —— Psidii, 270, 541
—— Nanoti, 545 — Rubicolor, 270, 547
—— Nervicolum, 645 — Rufomaculans, 264, 265, 266,
—— Nervisequum, 274, 641 267, 268, 269, 270, 271, 272, 539,
—— Olivarum, 543 541, 548
—— Opuntia, 544 ——Cyclaminis, 268
—— Pallidum, 544 Glomerularia, 566
—— Paradoxicum, 157, 541 Gloniella, 161

—— Pelargonii, 544 Glonium, 163

INDEX

Clumacee, 199

Glutinium, 481, 630

Glyceria, 383

Glycophila, 567

Glycyrrhiza, 187

Gnomonia, 264, 274, 529, 539

Caryze, 545

—— Erythrostoma, 275

—— Leptostyla, 275, 555

—— Oryze, 276

Padicola, 275, 496

—— Quercus lIllicis, 275

—— Rubi, 276

Veneta, 274, 274, 275, 498,
535, 541, 546

Gnomoniacex, 223, 263

Key to, 263

Gnomoniella, 233, 273, 539

Coryli, 274

—— Fimbriata, 274

—— Tubiformis, 274,
541

Gnomoniopsis, 264, 265

Godroniella, 534

Golden Rod, 179

Gonatobotrytidiz, 566

Gongromeriza, 596

Gooseberry, 141, 148, 155, 185, 245,
351, 433, 504, 519, 526

Gordonia, 150

Gorgonicepes, 136

Gossypium, 168

Gourd, 95, 247

Grain, 257, 260, 333, 384, 451, 508,
599, 620

Grallardia, 176, 178

Graminez, 143, 179

Grandinia, 413

Granularia, 640

Grape, 36, 37, 48, 51, 52, 73, 141, 148,
153, 192, 201, 231, 242, 249, 250,
253, 258, 267, 268, 281, 345, 398,
405, 463, :484, 486, 490, 491, 494,
498, 504, 506, 517, 520, 540, 541,
549, 554, 560, 579, 580, 620,
626

274, 529,

719

Graphiola, 323, 663

Pheenicis, 664, 665

Graphiothecium, 243

Graphium, 630

Grass, 8, 11, 24, 69, 73, 209, 210,
211, 213, 220, 259, 260, 303,
310, 312, 320, 321, 329, 333, 379,
383, 385, 405, 508, 520, 612, 635,
661

Green Algzx, 3

Grossulariz, 493

Guava, 271, 541

Guelichia, 641

Guignardia, 236, 237, 484

—— Ampelicida, 238

Bacce, 242

Bidwellii, 238, 238, 239, 241,
484, 490

—— Buxi, 243

—— Thee, 243

Vaccinii, 242, 242

Gymnoascacee, 165

Gymnoascus, 164

Gymnoconia, 355, 359, 390

—— Interstitialis, 360, 360

Gymnosporangium, 330, 355, 361,
362, 391

—— Biseptatum, 370

—— Clavarieforme, 331, 363, 366,
366

—— Clavipes, 363, 368

— Cornutum, 368, 371

— Hllisii, 369

—— Germinale, 368

— Globosum, 363, 366

Japonicum, 371

—— Juniperinum, 367

—— Juniperi-virginiane, 329, 363,
364

— Nelsoni, 363, 370

—— Nidus-avis, 363, 369

—— Sabine, 369

—— Terminali-juniperinum, 371

—— Transformans, 369

Yamadez, 371

Gyroceras, 596

720
H

Hackberry, 93

Hadrotrichum, 600
Hematomyces, 151
Hematomyxa, 151

Hainesia, 538

Halobyssus, 567

Hamamelis, 188

Haplaria, 575

Haplariopsis, 586
Haplobasidium, 597
Haplographiex, 595, 600

—— Key to, 600
Haplographium, 601
Haplosporella, 501
Haplotrichum, 571

Hariotia, 163

Harknessia, 501
Harpocephalum, 630
Harpographium, 630
Hartigiella, 670, 575

— Laricis, 570

Hartigiellez, 566, 570
Hawthorn, 38, 39, 130, 502, 525
Hazel, 122, 203, 249, 274, 280, 444
Hebeloma, 449

Hedera, 249, 487, 522, 541, 553
Helianthus, 92, 178, 179, 388
Helicobasidium, 403
Heliomyces, 445

Heliscus, 645

Hellebore, 505

Helminthospora, 609
Helminthosporium, 260, 564. 609, 611
—— Avene, 613

—— Bromi, 261, 613

—— Gramineum, 261, 612, 612, 614
—— Hever, 614

—— Iberidis, 614

—— Inequalis, 614, 614

—- Inconspicuum, 613, 614
— Lunarie, 614

—— Oryze, 614

—— Sativum, 618, 613

—— Sigmoideum, 613

INDEX

Helminthosporium, Sorokinianum,
613

—— Teres, 612, 613

—— Thez, 614

—— Trichostoma, 612

—— Tritici, 613

—— Tritici Repentis, 262, 613

—— Turcicum, 613, 614

— Vaceinii, 234

Helostroma, 634

Helotiacex, 133, 134

—— Key to, 135

Helotiexz, 136

Helotium, 136

Helvellacez, 131

Helvellales, 123, 130

—— Key to, 131

Hemiascomycetes, 114, 117, 118

Hemibasidii, 298, 299

Hemiglossum, 131

Hemileia, 354, 365

Oncidii, 356

—— Vastatrix, 355, 365

— Woodii, 356 :

Hemi-parasites, 2

Hemi-saprophytes, 2

Hemi-type, 328

Hemlock, 418, 419, 423, 435, 436, 438

Hemp, 52, 101, 141, 486, 494, 521, 581

Hendersonia, 257, 264, 515, b16

—— Acicola, 515

— Coffer, 615

—— Cydonz, 616

—— Foliicola, 516

— Mali, 615

— Notha, 616

—— Oryze, 516

—— Piricola, 516

—— Togniniana, 515, 616

Hendersonula, 515, 516

—— Morbosa, 219

Henriquesia, 160

Hepatica, 93, 357

Heptameria, 252

Heracleum, 591

Hericium, 413

INDEX

Herpotrichia, 226, 229, 230

—— Nigra, 229

Heterobotrys, 595

Heterocephalum, 634

Heterocontz, 3

Hetercecism, 64, 329

Heteropatella, 534

Heterospheria, 155

Heterosporium, 609, 610

Auriculi, 611

—— Echinulatum, 611

Gracile, 611

Laricis, 611

—— Minutulum, 611

—— Ornithogali, 611

—— Syringe, 611

Variabile, 611

Heterotheca, 408

Heuchera, 188

Hevea, 207, 278, 287, 411, 418, 437,
513, 544, 553, 607

Hexagonia, 417

Heydenia, 630

Hiatula, 450

Hibiscus, 488

Hickory, 428

Hicoria, 396

Himantia, 657

Holchus, 383

Hollyhock, 328, 386, 487, 492, 523,
552, 630

Holstiella, 280

Holwaya, 151

Homostegia, 216

Honey dew, 190

Honeysuckle, 36, 191

Hop, 8, 36, 93, 175, 279, 486, 490,
563, 569, 590, 611

Hordeum, 180, 317, 379

Hormiactella, 601

Hormiactis, 586

Hormiscium, 596

Hormodendrum, 600, 601

—— Cladosporioides, 248

—— Hordei, 601, 601

Hornbeam, 152, 274

721

Horse Chestnut, 445, 460, 524

Horse Radish, 95, 96, 506, 522, 582,
590, 619, 629

Hoya, 544

Humulus, 176, 178

Hyacinth, 27, 42, 44, 75, 143, 231,
260, 603

Hyaloceras, 558

Hyalodema, 593

Hyaloderma, 1£0

Hyalodothis, 217

Hyalopus, 570.

Hyalospora, 341

Hydnacez, 402, 413

Key to, 413

Hydnochete, 414

Hydnun, 414, 414

—— Diversidens, 415

—— Erinaceus, 414, 414

—— Schiedermayeri, 415

—— Septentrionale, 414

Hydrangea, 347, 488, 493, 522

Hygrophorex, 442

Hymenium, 113

Hymenochete, 406

— Noxia, 411

Hymenogastrales, 396

Hymenomycetes, 394

Hymenopsis, 655

Hymenoscypha, 136, 146, 146

Temulenta, 146, 642

Hymenula, 640

Hypha, 657

Hyphene, 193

Hyphoderma, 575

Hypholoma, 449, 450

— Appendiculatum, 451, 451

— Fasciculare, 451

Lateritium, 451

Hyphomycete, 321, 402, 663

Hyphostereum, 640

Hypocenia, 501

Hypochnacee, 402

— Key to, 403

Hypochnus, 403, 406

— Cucumeris, 404

722 INDEX

Hypochnus, Filamintosus, 404 Hysterium, 164

— Fuciformis, 404 Hysteroglonium, 163
—— Ochroleucus, 403 Hysterographium, 164
—— Solani, 404 —— Fraxini, 164, 164
—— Thee, 404 Hysterostomella, 163

Hypochytriacez, 67
Hypocopra, 224
Hypocrea, 209, 199 I
—— Ceretiformis, 209
td Tberis, 614
— 209 p
Sacchari, 20! Tex, 188

196

Hypocreacee, Ilosporium, 641, 643

—— Key to, 196 — Maculicola, 644, 6.

Hypocreales, 124, 196, 584 aie ea
—— Malifoliorum, 643

Hypocreex, 197 i

C Impatiens, 93, 176
——Key to, 198 Inocybe, 449
19 :
Hypocrella, 199 Ipomez, 337

dendron, 527 é
sae a Iris, 27, 41, 46, 73, 389, 507, 514, 522,
608, 611, 619, 620

16
eee ea Irish Potato, 105, 106
—— Desmazieri, 161

ici Irpex, 414, 415
—— Laricis, 161 i ne
—— Pinicola, 161 Seine
—— Strobicola, 161 —— Flavus, 416, 415

Hypodermatacee, 160 sy a 415
— Key to, 1€0 aTaCOXUS,

Hypodermella, 160, 161 Isaria, 196, 634, 635

ici —— Fuciformis, 635
—— Laricis, 161 A ee ee
— Sulicigena, 161 jes cape ee a,
Hypodermium, 538, 647 ee Pe F pa
—— Orchidearum, 547 Teik es ay
Hypolyssus, 405 “i = ie
Hypomyces,, 197, 200, 200 ajahya,

—— Hyacinthi, 200 Ivy, 152, 493, 497, 544

— Solani, 200

Hypomycetezx, 196, 197 J

Hyponectria, 201

Hyponectriex, 196 Jansia, 462

Hypospila, 276 Johnson Grass, 311

Hypoxylee, 285 Juglans, 186, 275, 396, 507
Hypoxylon, 285 Juncus, 303

Hysteriacex, 160, 163, 530 Juneberry, 38

— Key to, 163 June Grass, 578

Hysteriales, 124, 159 Juniper, 52, 157, 162, 220, 230, 243,
—— Key to, 160 « 330, 560

Hysteriopsis, 161 Juniperus, 362, 365, 366, 367, 368,

—— Brasiliensis, 161 369, 370, 371, 516, 610

INDEX

K

Kalmusia, 277
Kawakamia, 83, 89
Cyperi, 89
Keithia, 156
Kellermania, 513
Klachbrennera, 464
Kmetia, 640
Kneiffiella, 413
Kuehneola, 355, 361
Gossypii, 361
Uredinis, 361

L

Laboulbeniales, 124
Labrella, 529, 530
Coryli, 529, 530
Piricola, 530
Laburnum, 544
Lachnella, 135, 145, 145
Pini, 145
Lachnellula, 135
Lachnocladium, 412
Lachnodochium, 641
Lachnum, 136
Lactariex, 423, 443
Lestadia, 238
—— Buxi, 243
Lamyella, 483
Langloisula, 576
Larch, 145, 161, 162, 249, 348, 419,
424, 432, 436, 438, 530, 570, 611,
656, 658
Larix, 230, 344
Larkspur, 43
Laschia, 417
Lasiobotrys, 189, 191
Lonicere, 191
Lasioderma, 634
Lasiodiplodia, 510, 513
Theobroma, 513
—— Tubericola, 513
Lasionectria, 201

723

Lasiosphzria, 226

Lasmenia, 531

Laternea, 463, 464

—— Columnata, 464, 464

Lathyrus, 217, 313, 372

Laurel, 492

Laurel, Cherry, 409

Laurus, 398, 489

Lecythium, 128

Legume, 28, 31, 32, 313, 373

Lemalis, 521, 534

Lembosia, 163

Lemon, 77, 494, 508, 510, 512, 518,
540, 549, 574, 582, 604

Lemonniera, 593

Lentinus, 445

Conchatus, 446

—— Lepideus, 446, 446

—— Variegata, 446

Lentomita, 232

Lenzites, 417, 439

—— Abietina, 440

—— Betulina, 440, 441

—— Corrugata, 440

Sepiaria, 440

—— Variegata, 440

Vialis, 440

Leocarpus, 11

Lepiderma, 10

Lepidonectria, 201

Lepotia, 450

Leptoglossum, 443

Leptomitacee, 75

Leptonia, 450

Leptopus, 443

Leptospheria, 252, 257, 519, 660

—— Circinans, 268

—— Coniothyrium, 257, 258, 504

Herpotrichoides, 258

—— Iwamotoi, 258

—— Napi, 258, 616

—— Phlogis, 258, 519

—— Rhododendri, 268

—— Sacchari, 258

—— Stictoides, 258

Taxicola, 259

724

Leptospheria, Tritici, 258, 520
—— Vagabunda, 259
—— Vitigena, 258
Leptospora, 226
Leptostroma, 529, 530
—— Larcinum, 249, 530
—— Piricola, 530
—— Punctiforme, 530
Leptostromatacee, 479, 528
—— Key to, 528
—— Hyalodydima, 528
—— Hyalospore, 528

—— Key to, 528
—— Hyalophragmie, 528, 531
Key to, 531
—— Phezodidyme, 528
~— Pheopharagmie, 528
—— Phezospore, 528, 531
Key to, 531
—- Scolecospore, 528, 532
Key to, 532
Leptostromella, 532, 533
—— Elastice, 533, 533
Leptothyrium, 274, 528, 529
—— Acerinum, 529
—— Alneum, 274, 529
—— Buxi, 529
—— Macrothecium, 529
— Oxycocci, 529, 529
—— Parasiticum, 629
—— Peonz, 529
—— Periclymeni, 529
—— Pomi, 529
Lepto-type, 328
Lespedeza, 187
Lettuce, 36, 37, 44, 52, 95, 141, 142,

408, 507, 522, 555, 556, 579, 620

Levieuxia, 501
Levisticum, 28
Libertella, 562, 564
—— Rubra, 208, 564
—— Ulcerata, 564
Libertiella, 527
Liceacez, 9
Lichenopsis, 515
Lichens, 134

INDEX

Lilac, 88, 404, 488,-581, 582, 611

Liliacew, 310, 318, 320

Lilium, 375

Lily, 106, 141, 250, 488, 563, 579, 580,
592, 631

Lily-of-the-valley, 523, 581

Limacinia, 190

—— Tangensis, 193

Lime, 203, 249

Limnanthemum, 315

Linaria, 168

Linden, 259, 421, 545, 560

Linospora, 276

Linum, 607

Liriodendron, 188, 258, 547

Lisea, 197

Lisiella, 197

Listeromyces, 657

Lizonia, 226

Lobelia, 492

Locellina, 449

Loculistroma, 199, 215

—— Bambuss, 215

Locust, 419, 434

Locust Black, 438

Lolium, 73, 383

Lonicera, 186, 191, 529

Lopharia, 413

Lophiostomatacee, 223

Lophium, 164

Lophodermium, 161

—— Abietis, 162

-——— Brachysporum, 162

— Gilvun, 162

—— Juniperinum, 162

—— Laricinum, 162

—— Macrosporum, 162, 162

—— Nervisequum, 162

—— Pinastri, 161, 162

Loquot, 553

Lunaria, 614

Lupine, 560, 564, 652

Lupinus, 43, 178, 313

—— Albus, 168

—— Augustifolius, 168

— Iuteus, 168

INDEX 725
Lupinus, Thermis, 168 Macrosporium, Nobile, 619
Luzula, 303 — Porri, 618
Lycoperdacer, 464 —— Ramulosum, 619
—— Key to, 464 —— Rugosa, 624

Lycoperdales, 395, 464
Lycoperdon, 465
Gemmatum, 465, 465
Lycopersicum, 178
Lysurus, 463

M

Macrodendrophoma Salicicola, 253,
494

Macrobatis, 514

Macrodiplodia, 510

Macrophoma, 284, 481, 498

Abietis, 493

—— Curvispora, 493, 493

—— Dalmatica, 493

—— Helicinia, 493

—— Hennebergii, 493

—— Ligustica, 493

—— Malorum, 493

— Manihotis, 493

—— Reniformis, 494

—— Taxi, 493

— Vestita, 493

Macrosporium, 616, 618

—— Aductum, 619

—— Alliorum, 618

—— Brassice, 619

—— Catalpx, 619

—— Cheiranthi, 619

—— Cladosporioides, 620

Commune, 260, 618

—— Cucumerinum, 619, 620

—— Fasciculata, 624

Gramineum, 620

—— Herculeum, 618

—— Iridis, 619

—— Longipes, 619

—— Lycopersici, 624

—— Macalpinianum, 620

— Nigricanthium, 619

—— Saponarie, 620
—-— Sarciniforme, 619
—— Sarcinula-parasiticum, 618
— Tabacinum, 619
—— Tomato, 624
—— Uvarum, 620
—— Verrucosum, 620
—— Viole, 620
Macrostilbum, 634
Madia, 92
Magnolia, 188, 503, 559
Magnuusia, 166
Magnusiella, 126
Maguey, 220
Mahonia, 379
Malbranchea, 567
Mal-di-gomma, 649
Malope, 386
Malus, 371
Malva, 386
Malvacez, 507
Mamiania, 263
Mandarin, 520
Mangel, 41, 645
Mango, 191, 193, 543
Mangold, 491, 581
Manihot, 557
Maple, 72, 130, 152, 159, 182, 203,
419, 421, 428, 430, 436, 455, 489,
524, 525, 545, 557, 563, 632
Marasmier, 443, 445
Key to, 445
Marasmius, 445, 446
—— Equicrinus, 448
—— Hawiiensis, 448
—— Plicatus, 447, 448
—— Sacchari, 448
—— Sarmentosus, 448
—— Semiustus, 448
Marchalia, 156
Marchaliella, 189
Marssonia, 147, 274, 555

726

Marssonia, Castagnei, 157, 655
—— Juglandis, 275, 565
—— Martini, 565

—— Medicaginis, 556
—— Panattoniana, 555
—— Perforans, 555

—— Populi, 555

—— Potentille, 655

—— Rose, 555

—— Secalis, 555

—— Viole, 556, 556
Martensella, 576
Martindalia, 633
Massalongiella, 236
Massaria, 263

—— Theicola, 268
Massariacez, 223, 262
—— Key to, 262
Massarina, 263
Massariovalsa, 263
Massospora, 566
Mastigosporium, 588, 590
Mastomyces, 155, 514
—— Friesii, 614
Matrouchotia, 403
Mattirolia, 198
Mazzantia, 216

Medicago, 178

Medick, 148

Medlar, 140, 150, 569
Megalonectria, 198
Melanconiales, 479, 527
Melampsora, 340, 342, 390
— Allii-fragilis, 344
—— Allii-populina, 344
—— Allii-salicis albz, 344
—— Bigelowii, 344

—— Klebahni, 344

—— Larici-pentandre, 344
—— Larici-populina, 344
—- Lini, 342

—— Meduse, 343

—— Pinitorqua, 344

—— Repentis, 344

— Ribesii-viminalis, 344
—— Rostrupii, 344

INDEX

Melampeora, Saxifragarum, 345
Melampsoracez, 335, 340

—— Key to, 340
Melampsorella, 341, 348, 390, 391
—— Elatina, 348

Melampsoridium, 341, 347, 347, 391

— Betulz, 348

Melampsoropsis, 341, 349, 350, 391

— Rhododendri, 349

Melanconiacez, 537

—— Key to, 537

— Hyalodidyme, 538, 555
—— Key to, 555

— Hyalophragmiz, 538, 556
—— Key to, 556

—— Hyalospore, 538
— Key to, 538

—— Pheodictye, 537, 561

—— Phzodidyme, 537, 556
— Key to, 556

—— Phzophragmie, 537, 557
— Key to, 557

—— Pheospore, 537, 553
—— Key to, 553

~— Scolecospore, 537, 561

Key to, 562

—— Staurospore, 537

Melanconiales, 265, 525, 537, 564

Mclanconidacee, 223, 279

—— Key to, 279

Melanconiella, 279

Melanconiopsis, 501

Melanconis, 279, 281

— Modonia, 281, 498, 560

Melanconium, 553, 554

— Fuligineum, 564, 554

—— Pandani, 554

—— Sacchari, 554

Melanomma, 227, 282

—— Glumarun, 282

—— Henriquesianum, 231

Melanops, 283, 284, 503

Melanopsamma, 227

Melanopsichium, 302

Melanospora, 196, 197, 200, 201

—— Damnosa, 200

INDEX 727

Melanospora, Stysanophora, 201
Melanosporez, 196, 197
Melanostroma, 538
Melanotznium, 314
Melasmia, 158, 529, 630
—— Acerina, 159, 580

—— Punctata, 530

— Salicina, 530

Melica, 497

Melilotus, 508

Meliola, 189, 190, 191, 198, 193, 624
—— Camellia, 193, 193, 625
Niessleanea, 194
Penzigi, 194
Melogramma, 283
Henriquetii, 284
Melogrammatace, 223, 282
—— Key to, 283

Melon, 10, 27, 487, 608, 621, 629
Melophia, 532

Mentha, 178

Merasmier, 443, 445

Key to, 445
Merasmiopsis, 445
Mercurialis, 344

Meruliex, 416, 418
Merulius Lacrymans, 418
Mesospore, 327, 375, 384
Mespilus, 570

Metanectria, 198
Metasphezria, 252, 257

—— Albescens, 257
Michenera, 405
Micothyriacez, 170
Microascus, 166

Microcera, 207

Micrococcus, 18, 21
Albidus, 21

—— Delacourianus, 21
—— Flavidus, 21

-—— Imperatoris, 21

—— Nuclei, 21

—— Pellucidus, 21

—— Phytophthorus, 21
—— Populi, 21

—— Tritici, 21

Microdiplodia, 610

—— Anthurii, 611

Microglossum, 131

Micropera, 518

Microspatha, 634

Microsphera, 175, 185

—— Alni, 186, 186, 570
—— Calocladophora, 186
—— Extensa, 186
— Lonicere, 186
—— Vaccinii, 186

— Berberidis, 185

—— Beta, 187

—— Diffusa, 186

— Elevata, 186

—— Euphorbie, 187

—— Ferruginea, 187

— Grossularie, 185, 185

Microstroma, 396

Album, 396

— Juglandis, 396

Microthyriacex, 170, 195

Microthyrium Coffee, 195

Micro-type, 328

Micula, 518

Mignonette, 81, 631

Mikronegeria, 336

Millet, 90

Milowia, 588

Mitrula, 131, 132

— Sclerotiorum, 132

Mohonia, 379

Molds, Slime. See Myxomycetes.

Mollisia, 146

Mollisiacez, 134, 146

—— Key to, 146

Mollisiella, 146

Monacrosporium, 588

Monascacee, 118

Monilia, 137, 138, 140, 567, 568

— Cinerea, 139, 569

— Crategi, 569

—— Fimicola, 569

—— Fructigena, 139, 569

—— Laxa, 569

—— Linhartiana, 569

728 INDEX

Monilia, Seaveri, 140, 569 Mucor, Pyriformis, 106
Moniliacexe Scolecospore, 592 —— Racemosus, 106
Moniliacesr, 565 Mucoracez, 103, 107
—— Key to, 565 —— Key to, 104
—— Amerospore, 565 Mucorales, 66, 102
— Key to, 565 — Key to, 103
—— Chromosporiex, 565 Mucorer, 104
— Key to, 566 Mucronella, 413
—— Dictyospore, 565, 592 Mucrosporium, 589
—— Key to, 592 Mulberry, 21, 31, 438, 52, 73, 393,
—— Didymospore, 565, 585 445, 454, 499, 557, 561, 582, 626,
—— Key to, 585 658
—Helicospore, 565, 593 Mullerella, 236
—— Oésoporezx, 565, 567 Munkia, 527
— Key to, 567 Munkiella, 217
—— Phragmospore, 565, 588 Muricularia, 482, 527
—— Key to, 588 Muscari, 375
—— Staurospore, 565, 593 Mushroom, 200, 398, 567, 569, 574,
— Key to, 593 584, 587
Moniliales, 464, 479, 554 Muskmelon, 44, 51, 95, 247, 487
—— Key to, 465 Mutinus, 462
Monilochetes, 596, 597 Mycelia Sterilia, 479, 659
—— Infuscans, 597 —— Key to, 659
Monoblepharidiales, 66 Myceliophthora, 566, 567
Monochetia, 558 —— Lutea, 567
—— Pachyspora, 658 Mycelophagus Castanex, 101
Monocotyledones, 611 Mycena, 450, 460, 461
Monographus, 217 —— Epipterygia, 460
Monopodium, 576 Mycenastrum, 465
Monospore, 121 Mycogala, 481
Monosporium, 576 Mycogone, 200, 586, 587, 587
Monotospora, 600 —— Perniciosa, 200, 587
Monotosporee, 595, 600 —— Rosea, 200, 587
— Key to, 600 Mycoplasm Theory, 333
Montagnella, 216 Mycospherella, 236, 248, 484, 490,
Montagnites, 442 519, 525
Moon Flower, 82 —— Abietis, 249
Morel, 114 —— Brassicecola, 249, 484
Morning Glory, 82, 337 —— Cerasella, 245, 625
Mortierellaceze, 103 —— Cinxia, 250
Morus, 182, 202, 207, 231, 249, —— Citrullina, 246, 248, 509
491, 499, 503, 512, 517, 525, —— Coffer, 249
562 —— Coffeicola, 260
Mountain Ash, 39, 367, 368, 427 -——— Comedens, 249
Mucor, 90, 101, 104, 105, 106 —— Convexula, 250

—— Mucedo, 106 —— Cydoniz, 249

INDEX 729

Mycospherella, Elastica, 249 Mystrosporium, Alliorium, 620

—— Fagi, 249 Myrothecium, 655

—— Fragarie, 244, 244, 519, 590 Mytilidium, 164

—— Fusca, 260 Myxobacteriales, 19

—— Gibelliana, 249 Myxogastrales, 5, 9

—— Gossypina, 248, 625 —— Key to, 9

—— Grossularie, 245 Myxomyeetes, 1, 3, 5

—— Hedericola, 249 — Key to, 5

—— Hondai, 250 Myxormia, 538

~-— Laricina, 249, 530 Myxosporella, 588

—— Leefgreni, 249 Myxosporium, 274, 538, 546

—— Maculiformis, 249, 485, 562 ——— Abietinum, 547

—— Mori, 557 —— Carneum, 547

—— Morifolia, 249, 562 —— Corticolum, 493, 546, 546

——- Pinifolia, 249 —— Devastans, 547
Pinodes, 260, 506 —— Lanceola, 547

—— Populi, 249, 519, 635 —— Longisporum, 547

—— Primule, 250 —— Mali, 547

—— Punctiformis, 249 —— Piri, 647

—— Rosigena, 249 —— Valsoideum, 274, 646

—— Rubina, 245 Myxotrichellez, 595

Sentina, 246, 246, 247, 249, 519
—— Shiraina, 250

Stratiformans, 248 N
—— Tabifica, 247, 485, 490
—— Tamarindi, 250 Nemosphera, 501
—— Taxi, 249 Nemospora, 122, 538, 647, 562
— Tulasnei, 247, 603 —— Ampelicida, 238
— Ulmi, 249, 484 —— Coryli, 122
Vitis, 249 —— Crocea, 547
Mycospherellacer, 223, 236 Napicladium, 609, 611
Key to, 235 Janseanum, 611
Mykosyrinx, 302 —— Soraueri, 255, 611
Myrangiella, 170 Narcissus, 389, 489, 523, 591, 592, 611
Orbicularis, 170 Nasturtium, 37, 168, 260
Myrangium, 170 Naucoria, 449
Myriangiacee, 165, 170 Necator, 640, 643
—— Key to, 170 -—— Decretus, 643
Myriogenospora, 216 Necrosis, 281
Myriostoma, 465 Nectarine, 604
Myrmeciella, 283 Nectria, 197, 201, 475, 646
Myrmecium, 283 —— Amerunensis, 204
Myroiphysa, 655 —— Bainii, 204
Mystrosporium, 616, 620 —— Bogoriensis, 205
Abrodens, 620 —— Bulbicola, 205

—— Aductum, 620 — Cinnabarina, 202, 202, 642

730

Nectria, Coffeicola, 204
—— Cucurbitula, 203
—— Ditissima, 203, 568
—— Diversispora, 204
—— Fruticola, 205
—— Gigantispora, 205
— Goroshankianna, 205
—— Graminicola, 205
— Ipomcen, 204, 204, 205
—— Jungeri, 205
—— Luteopilosa, 205
—— Pandani, 204
—— Ribis, 204
—— Rousselliana, 204, 656
—— Solani, 204
—— Striatospora, 205
—— Theobrome, 205
—— Theobromicola, 205
—— Vande, 205
— Vanille, 206
Nectriacez, 196
Nectriee, 196
—— Key to, 197
Nectriella, 197
Nectrioidacer, 479, 526
— Key to, 526
— Hyalodidymiz, 526
— Hyalophragmiz, 526
—— Hyalospore, 526
—— Key to, 526
—— Ollulez, 526
— Phzospore, 526
——- Scolecospore, 526
—— Zythier, 526
Negeriella, 637
Negundo, 260, 489
Nematospora, 121
Nematosporangium, 75
Nemophila Auriculata, 168
Neobarclaya, 556
Neocosmospora, 197, 205, 475, 646,
651
Neolecta, 131
Neomichelia, 609
Neopeckia, 226
Neottiospora, 482

INDEX

Neovossia, 314, 315
Nephlyctis, 354
Nicotinia, 101, 168, 178, 486
Nidulariales, 396
Niesslia, 225
Nigrospora, 600
Niptera, 147
Nitschkia, 234
Nolanea, 450
Nothopatella, 501
Nowakowskiella, 72
Nummularia, 286

—— Discreta, 285, 286
Nyctaginacer, 303

O

Oak, 130, 152, 157, 162, 177, 186, 192,
193, 203, 220, 231, 249, 264, 275,
279, 281, 352, 396, 409, 410, 411,
A414, 415, 419, 421, 422, 424, 428,
430, 434, 436, 439, 440, 442, 452,
489, 498, 545, 546, 547, 555, 564,
570, 606

Oat, 23, 206, 213, 260, 301, 304, 305,
306, 380, 383, 490, 520, 550, 607,
608

Oat Grass, 307

Ochropsora, 336

— Sorbi, 336

Odontia, 413

Odontoglossum, 631

C&demansiella, 444

Cdemium, 598

(C£docephalum, 570

Cnothera, 71

Oidiopsis, 567

Oidium, 60, 172, 567, 569

—— Alphitoides, 570

—— Ambrosiz, 178, 569

—— Balsamii, 177, 569

—— Chrysanthemi, 569

—— Cratagi, 183, 569

—— Erysiphoides, 569

—-— Farinosum, 184, 569

INDEX

Oidium, Fragariz, 175, 669

Leucoconium, 176, 569

—— Mespilinum, 570

——— Monilioides, 179, 569

Quercinum, 570

Tabaci, 570

—— Tuckeri, 181, 569

Verbenz, 570

Okra, 650, 651

Oleace, 164

Oleander, 36, 45, 192, 193, 422, 524,
631

Oleina, 122

Olive, 34, 45, 155, 192, 198, 433, 486,
493, 543, 602, 624

Olopecurus, 383

Olpidiacee, 67, 69

— Key to, 68

Olpidiopsis, 68

Olpidium, 68, 69, 72

Brassicez, 68, 69

Olpitrichum, 575

Ombrophilex, 136

Omphalia, 450

Oncidium, 356, 392, 544, 605

Oncopodium, 615

Oncospora, 537

Onion, 41, 42, 43, 52, 97, 200, 377,
491, 497, 499, 512, 520, 541, 549,
574, 581, 604, 606, 616, 618,
620

Onobrychis, 168

Onygenacee, 165

Oochytriacez, 67, 75

—— Key to, 73

Oomyces, 199

Oomycetes, 62, 65, 66, 101

Osspora, 475, 567, 568, 568

Abietum, 568

Scabies, 568

Ophiobolus, 252, 269, 259

Graminis, 269

—— Herpotrichus, 259

—— Oryzee, 259

Ophioceras, 232

Ophiocheta, 252

731

Ophiocladium, 566, 567
—— Hordii, 667, 567
Ophiodothis, 216
Ophiomassaria, 262
Ophionectria, 198, 207
— Coccicola, 207
— Foliicola, 207
Ophiotrichum, 609
Opsis-type, 328
Opuntia, 544
Orange, 207, 249, 256, 260, 409, 422,
435, 445
Orbicula, 189
Orcadellaceze, 9
Orchard Grass, 52, 550
Orchid, 46, 52, 205, 270, 392, 500,
541, 544, 547, 631
Orchis, 344
Ornithogalum, 71, 320
Osage Orange, 346
Ostreion, 164
Ostropacezx, 160
Ostrya, 188
Otthia, 234
Ovularia, 243, 577, 582, 582
— Alnicola, 582
—— Armoracie, 582
—— Canaigricola, 582
Citri, 582
—— Corcellensis, 582
—— Exigua, 582
—— Interstitialis, 582
—— Medicaginis, 582
—— Necans, 582
Primulana, 682
— Rosea, 582
—— Syringe, 582
Vicie, 582
—— Villiana, 582
Ovulariopsis, 188, 577, 582
Ulmorica, 582
Oxalis, 168, 329, 384
Ozier, 253
Ozonium, 657, 661
—— Omnivorum, 662

732

P

Pachybasium, 583

Pachysterigma, 403

Pactilia, 639

Peonia, 176, 178, 352

Pepalopsis, 567

Palm, 77, 88, 191, 323, 499, 545, 552,
560, 658, 664

Palmetto, 412

Pandanus, 204, 531, 554

Panicum, 305, 307, 310, 312, 314

Pansy, 99, 320, 488, 552, 654

Panus, 445, 446

—— Stipicus, 446

Papaver, 321, 322

Papulospora, 570

Paranectria, 198

Para Rubber, 101, 415, 487, 512,
614

Paraspora, 588

Parmularia, 163

Parodiella, 189

Parsley, 141, 377, 521

Parsnip, 36, 41, 42, 91, 592, 628

Paryphedria, 151

Paspalum, 213

Passalora, 602, 607

— Bacilligera, 607

—— Microsperma, 607

Patellariacer, 134

Patellina, 639

Patouillardia, 640

Patzschkeella, 505

Paulownia, 545

Paxiller, 442

Pea, 28, 99, 177, 248, 250, 260, 329,
373, 506, 519, 651

Peach, 36, 53, 106, 128, 137, 138,
176, 231, 268, 282, 357, 428, 485,
490, 499, 512, 539, 540, 541, 547,
560, 592, 604, 606

Peanut, 392, 557, 629

Pear, 38, 105, 130, 149, 202, 231, 246,
249, 253, 255, 268, 367, 369, 371,

404, 419, 421, 246, 279, 485, 490,-

INDEX

502, 515, 519, 530, 540, 546, 547,
553, 607

Pearl Millet, 90

Pecan, 250, 607, 632

Pecia, 482

Pedilospora, 593

Pelargonium, 36, 43, 389, 544, 620,
631

Pellicularia, 382, 577, 682

—— Koleroga, 583

Pellioniella, 510

Peltospheria, 276

Peltostroma, 531

Penicilliopsis, 167

Penicillium, 166, 167, 169, 169, 572,
573, 635

Digitatum, 574

—— Glaucum, 574

—— Italicum, 574

—— Luteum, 574

Olivaceum, 574

Peniophora, 406

Pennisetum, 209

Peony, 178, 529, 581, 606

Pepper, 37, 42, 268, 269, 540, 541

Peraphyllum, 371

Peribotryum, 634

Periconia, 598

Periconiex, 594, 597

—— Key to, 597

Periconiella, 597

Peridermium, 330, 333, 335, 336, 350,
389, 390

Acicolum, 337, 337

—— Cerebrum, 352

—— Cornui, 352

—— Elatinum, 349

—— Oblongisporium, 338

-——— Pyriforme, 352

— Rostrupi, 339

Strobi, 351

Peridinez, 3

Peridium, 325

Periola, 641

Perisporiacer, 170, 189

—— Key to, 189

Perisporiales, 116, 124, 165,
170

Key to, 170

Perisporium, 189

Perithecium, 62, 63

Peronoplasmopara, 83, 90, 93

Celtidis, 93

—— Cubensis, 93, 94

Humuli, 93

Peronospora, 78, 82, 84, 90, 93, 95,

618
—— Antirrhini, 101
——— Arborescens, 100
— Candida, 101
Cannabina, 101
—— Conglomerata, 101
—— Corolla, 101
—— Cytisi, 100
— Dianthi, 101
—— Dipsaci, 100
— Effusa, 96, 96
Ficarie, 101
Fragariez, 100
—— Jaapiana, 101
—— Linariz, 100
—— Maydis, 101
—— Myosotidis, 101
Nicotianz, 101
—— Parasitica, 95, 97
—— Phenixe, 101
Potentillz, 100
—— Rubi, 100
Schachtii, 100
—— Schleideni, 96, 98
—— Schleideniana, 96
—— Sparsa, 97
Trichomata, 100
—— Trifoliorum, 97
-—— Valerianz, 101
—— Valerianella, 101
—— Viciz, 97
—— Vince, 101
—— Violacea, 100
Viole, 99
Peronosporacez, 78, 82
Key to, 83

INDEX

Peronosporales, 66, 74, 75,
475
— Key to, 78
Persimmon, 540, 581
Pestalozzia, 558
—— Alaa, 560
—— Clusiz, 560
—— Discosioides, 560
—— Funerea, 559, 559
—— Fuscescens, 560
—Sacchari, 560
— Gongrogena, 560
—— Guepini, 559, 559
Hartigii, 558
—— Inquinans, 560
— Lupini, 560
—— Palmarum, 560
—— Palmicola, 560
— Pheenicis, 560
—— Richardiz, 560
— Stictica, 560
—— Suffocata, 560
—— Tumefaciens, 560
—— Uvicola, 559
Pestalozziella, 538
Pestalozzina, 557
Petunia, 48, 141
Pezizacex, 133, 134
Pezizales, 123, 133
— Key to, 133
Phacidiacee, 154, 165
— Key to, 155
Phacidiales, 124, 164
—— Key to, 154
Phacidiee, 156
Phacidium, 156, 157
Infestans, 157
Phaconectria, 201
Phzodon, 414
Pheonectria, 201
Pheopeltospheria, 276
Pheophycez, 3
Phzoseptoria, 517, 625
—— Oryze, 526
Pheospheriella, 236
Phallacee, 462

733

77,

734

Phallales, 395, 462

— Key to, 462

Phallus, 462, 463

—— Impudicus, 463

—— Rubicundus, 463

Pharcidia, 236, 250

— Oryzex, 250

Phaseolus, 178, 187, 372

—— Multiflorus, 168 °

—— Vulgaris, 168

Phellomyces, 614, 657

Phiebia, 413

Phlebophora, 406

Phleospora, 243, 249, 518, 519,
626

—— Aceris, 525

—— Caragane, 525

—— Mori, 526

— Moricola, 525

—— Oxycanthe, 526

Phleum, 180, 321, 374, 608

Phlox, 176, 178, 258, 497, 519, 523,
631

Phlyctena, 493, 518

Pheenix, 101, 658

Pholiota, 449, 462

—— Adiposa, 462, 453

— Aurivella, 452

—— Cervinus, 452

—— Destruens, 452

—— Mutabilis, 462

—— Spectabilis, 452

-—— Squarrosa, 452

Phoma, 238, 243, 245, 247, 257, 279,
325, 478, 481, 484, 490, 493, 519,
562

—— Albicans, 260, 490

—— Aleracea, 491, 492

—— Ambigua, 490

—— Apiicola, 492

—— Batate, 492

—— Betz, 247, 490

—— Bohemica, 276, 490

—— Brassice, 492

Phoma, Chrysanthemi, 492

INDEX

Phoma, Citricarpa, 491
—— Cyclamene, 492
—— Cydonz, 490

—— Dahliz, 492

—— Devastatrix, 492
—— Hennebergii, 491
—— Limonis, 490

— Lophiostomoides, 491
—— Mali, 490

—— Malvacearum, 492
— Mororum, 491

—— Myxie, 491

—— Napobrassice, 491
—— Oleandrina, 492

—— Oleracea, 491, 492
—— Persice, 490

—— Pithya, 492

—— Pomarum, 491

— Reniformis, 242, 490
— Ribesia, 492

—— Roumii, 492

—— Sanguinolenta, 491
—— Sarmentella, 490
— Solani, 491

—— Solanicola, 491

—— Sordida, 492

~—— Spherosperma, 247
— Strobi, 492

—— Strobilinum, 492
—— Subcircinata, 491
—— Tilie, 259

—— Tuberculata, 491
—— Uvicola, 238
Phomatospora, 263
Phomopsis, 482, 493

—— Aloeapercrasse, 493
—— Stewartii, 493
Phorcys, 263
Phragmidium, 354, 358, 390
Americanum, 369, 359
—— Bulbosum, 358

—— Discifiorum, 359, 359
—— Montivagum, 359, 359
—— Rose-acicularis, 359

—— Rose-arkansane, 359, 359

—— Rose-californice, 369, 359

INDEX

Phragmidium, Rose-setigerz,
359

—— Rubi-idai, 359

—— Speciosum, 359

—— Subcorticium, 359

—— Violaceum, 359

Phragmites, 315, 377, 378

Phragmopyxis, 354

Phragmospore:, 633, 637

—— Key to, 637

Phycomyces, 105

Phycomycetes, 1, 3, 59, 64, 65, 101,
113, 116, 118

— Key to, 65

Phyllachora, 157, 217, 220, 221, 606,
607

— Cynodontis, 221

—— Dapazioides, 221

Graminis, 220, 220

—— Makrospora, 221

— Poe, 221

—— Pomigena, 220

—— Sorghi, 221

— Trifolii, 220, 606

—— Ulmi, 557

Phyllactinia, 171, 173, 175, 187,
582

—— Corylea, 174, 187, 188

Phyllostachys, 215

Phyllosticta, 148, 238, 242, 243, 325,
476, 481, 488, 490, 519

—— Acericola, 489

—— Aceris, 489

—— Althezina, 487

—— Ampelopsidis, 484

—— Apii, 487

——- Argillacea, 487

—— Armenicola, 486

Bataticola, 486

—— Bellunensis, 249, 484

— Bete, 486

Bizzozeriana, 486

Brassica, 484

Brassicecola, 249

—— Cannabinis, 486

—— Catalpax, 489

359,

Phyllosticta, Cavarz, 489
—— Chenopodii, 487
—— Chrysanthemi, 488
Cinnamoni, 487
—— Circumscissa, 486
—— Citrullina, 487
— Coffeicola, 486
—— Comeensis, 486
—— Cruenta, 488

—— Cucurbitacearum, 487, 629
—— Cyclaminis, 488
— Dammarze, 489
—— Dianthi, 488

—— Digitalis, 488

— Dracene, 489
—— Fragaricola, 486
—— Funckia, 489

—— Grossularie, 486
—— Halstedii, 488
—— Hederacea, 487
—— Hedericola, 487
—— Hevea, 487

—— Hortorum, 487
—— Humuli, 486

—— Hydrangee, 488
— Idecola, 488

— Ilicina, 489

— Insulata, 486

—— Japonica, 486
Labrusce, 238, 484
—— Leucanthemi, 488
—— Liliicola, 488

—— Limitata, 485
—— Maculicola, 487
—— Maculiformis, 249, 485
—— Magnolie, 489
—— Malkoffi, 486

—— Medicaginis, 486
—— Minima, 489

—— Miuria, 486

—— Narcissi, 489

—— Nicotiana, 486
—— Nobilis, 489

—— Olex, 486

—— Opuntiz, 488

—— Pavie, 489

735

736

Phyllosticta, Persice, 485

—— Phaseolina, 487
—— Piricola, 485
—— Pirina, 485
—— Primulicola, 488
— Prunicola, 486
—— Pteridis, 489

—— Putrefaciens, 486

—— Richardie, 488
—- Rose, 487
— Rosarum, 487

—— Solitaria, 484, 485, 486
—— Spheropsidea, 489

—— Succedanea, 486
—— Syringe, 488
—— Tabaci, 486

—— Tabifica, 247, 485

— Tiliz, 489
—— Ulmicola, 489
—— Viale, 486

-_— Vince-minoris, 488

-— Viole, 488

-—— Viridis, 489
—— Vitis, 486 -
Phymatotrichum, 576
Physalacria, 412
Physalis, 48, 322

Physalospora, 238, 251, 262, 262, 273,

539
—— Abietina, 263

— Cattleye, 253, 541

—— Fallaciosa, 253

—— Gregaria, 252, 494

—— Laburni, 263
—— Vanille, 263
—— Woronini, 253
Physaracee, 10, 11
— Key to, 11
Physarella, 12
Physarum, 12, 12
—— Bivalve, 12
—— Cinereum, 12
Physoderma, 72
Physopella, 340, 345
—— Fici, 345

— Vitis, 345

INDEX

Physospora, 575
Phytolacca, 408

Phytomyxa Leguminosarum, 8

Phytophthora, 78, 83, 84, 88, 90, 617

—— Agaves, 89
—— Cactorum, 88
—— Calocasie, 89
—— Faberi, 88
—— Fagi, 88

—— Infestans, 84, 85, 86, 87

—— Nicotianz, 89

—— Omnivora, 88, 89

— Arece, 88

— Phaseoli, 84, 84, 86

— Sempervivi, 88
—— Syringe, 88

Picea, 145, 235, 253, 349, 391, 408

Pichia, 121
Piggotia, 528, 580

—— Astroidea, 221, 530

—— Fraxini, 530
Pigweed, 408
Pilacre, 634
Pilaira, 104
Pileotaria, 354
Piloboler, 104
Pilobolus, 104

—— Crystallinus, 105

Pilocratera, 135
Pilosace, 449
Pinacee, 88

Pine, 22, 52, 141, 145, 151, 157, 161,

162, 203, 230, 233, 249, 330,
351, 352, 391, 401, 415, 418,
423, 424, 432, 431, 436, 438,
446, 454, 460, 492, 499, 512,
516, 524, 531, 532, 654, 660
Pineapple, 496, 512, 596

Pink, 349, 507

Pinus, 161, 337, 338, 339, 340,

352, 390, 408
Pionnotes, 645
—— Betz, 645
—— Rhizophila, 645

Piptocephalidacer, 103

Piptostomum, 481

333,
419,
440,
515,

351,

Pirella, 105

Piricularia, 589, 691
Caudata, 592
— Grisea, 691, 591, 614
Oryz, 592, 614
Pirobasidium, 633
Pirostoma, 531
Farnetianum, 631
Pirottza, 147
Pistillaria, 412

Pisum, 168, 178, 372, 605
Pithomyces, 645

Pitya, 136
Placospheeria, 483
Placospherella, 505
Plagiorhabdus, 483, 500
—— Oxycocci, 600, 500
Planococcus, 18
Planosarcina, 18
Plantago, 69, 96, 179
Plasmodiophora, 6
—— Brassice, 6, 7
Californica, 8
— Humiili, 8
Orchidis, 8
Tomati, 8

Vitis, 8
Plasmodiophorales, 5
—— Key to, 6
Plasmopara, 82, 83, 90, 93, 95
—— Halstedii, 91

—— Nivea, 91

—— Obducens, 93
—— Pygmea, 93

— Ribicola, 92
Viticola, 91, 92
Platanus, 186, 205, 535
Platygloes, 392
Plectothrix, 576
Plenodomus, 482
Pleococcum, 534
Pleogibberella, 198
Pleolpidium, 68
Pleomassaria, 263
Pleomeliola, 190
Hyphenes, 198

INDEX

Pleonectria, 198, 207
—— Berolinensis, 207
—— Coffeicola, 207
Pleophragmia, 224
Pleospherulina, 236, 260
—— Briosiana, 250

737

Pleospora, 252, 259, 259, 611, 618

—— Albicans, 260, 269, 490
—— Avene, 262

—— Bromi, 261, 613

—— Gramineum, 261, 612
—— Herbarum, 260, 618
—— Hesperidearum, 260, 616
—— Hyacinthi, 260, 603
——— Infectoria, 260

—— Negundinis, 260

—— Oryze, 260

—— Pisi, 260

—— Putrefaciens, 260
—— Teres, 262

—— Trichostoma, 260, 262, 612, 621

—— Tritici, 258

—— Tritici-repentis, 262, 613
—— Tropeeoli, 260, 621
—— Ulmi, 260

—— Vulgaris, 610
Pleosporacez, 223, 260
—— Key to, 251
Pleotrachelus, 68
Pleurotus, 450, 454, 569
—— Atrocceruleus, 455
—— Corticatus, 455
—— Mitis, 455

—— Nidulans, 465
—— Ostreatus, 454, 456
—— Salignus, 454

—— Ulmarius, 464
Plowrightia, 216, 217
—— Agaves, 220

— Morbosa, 218, 218, 219, 516

—— Ribesia, 220
Virgultorum, 220

Plum, 32, 38, 129, 138, 184, 219, 271,
278, 282, 357, 433, 516, 520, 562,

586, 604
—— Pockets, 129

738

Pluteolus, 449

Pluteus, 450, 454

—— Cervinus, 454, 455
Poa, 8, 119, 180, 221, 310, 321, 375
Pocillum, 136
Pocospheeria, 252
Podocapsa, 122
Podocarpus, 597
Podocrea, 199
Podosphera, 175, 182
—— Leucotricha, 184, 569
— Mpyrtillina, 183

—— Oxyacanthe, 183, 183, 184, 569
—— Tridactyla, 183, 184
Podosporiella, 637
Podosporium, 637
Polemonium, 507
Polycephalum, 633
Polyscytalum, 568
Polydesmus, 609
Polygonum, 96, 303
Polymorphism, 64
Polynema, 534
Polyphagus, 73
Polyporacer, 402, 416
Key to, 416
Polyporee, 416

Polyporus, 417, 418, 426
—— Adustus, 426

——— Amarus, 422

—— Betulinus, 425, 425
—— Borealis, 422, 423, 423
—— Dryadeus, 423

—— Dryophillus, 421
—— Fruticum, 422

—— Giganteus, 421

—— Glivus, 421

—— Hispidus, 421

—— Obtusus, 418

—— Schweinitzii, 400, 401, 424
—— Squamosus, 419, 420
—— Sulphureus, 419, 479
Polystictus, 417, 418, 426
—-— Cinnabarinus, 4265
—— Hirsutus, 426

—— Occidentalis, 425

INDEX

Polystictus, Pergamenus, 426, 426

—— Sanguineus, 425

—— Velutinus, 425

— Versicolor, 425, 427

Polystigma, 198, 207

— Ochraceum, 208

—— Rubra, 208, 208, 564

Polythelis, 354

Polythrincium, 602, 606

Trifolii, 220, 606, 606

Pomelo, 549, 604

Pomes, 139, 237, 255, 278, 282, 362,
410, 491, 496, 502, 529, 569, 607,
649

Poplar, 21, 36, 47, 180, 182, 256, 340,
342, 419, 433, 440, 446, 454, 507,
535, 556, 606

Poppy, 100

—— Mallow, 390

Populus, 127, 130, 249, 344, 499, 512,
519, 545, 555

Poria, 418

—— Hypolaterita, 418

—— Lavigata, 418

—— Subacida, 418

—— Vaporaria, 418

—— Vineta, 418

Poropeltis, 531

Porothelium, 440

Potato, 8, 21, 40, 41, 43, 44, 46, 47,
48, 49, 69, 70, 86, 141, 200, 231,
258, 404, 408, 456, 491, 497, 568,
583, 584, 591, 614, 616, 617, 623,
624, 627, 637, 645, 652, 653

—— Beetle, 48

Potentilla, 175

Powdery Mildew, 171

Primrose, 101, 250, 320, 552, 582

Primula, 315, 318, 488, 507, 579, 582,
591

Primulacez, 101

Prismaria, 593

Privet, 191, 269, 541

Promycelium, 63, 300

Prophytroma, 600

Prospodium, 354

INDEX

Prosthemiella, 557
Prosthemium, 515
Protoascomycetes, 114, 117, 119
Protobasidii, 299, 323
—— Key to, 323
Protocoronospora, 405, 409
Nigricans, 409
Protodiscales, 114, 123, 1265
Key to, 125
Protomyces, 118, 119
Macrosporus, 119
—— Pachydermus, 119
—— Rhizobius, 119
Protomycetacex, 118
Key to, 118
Protomycetales, 118
Key to, 118
Protostegia, 536
Prunus, 129, 130, 140, 152, 182, 183,
184, 202, 208, 275, 347, 357, 486,
495, 496, 563, 564, 569, 579, 605,
610, 626
Psathyra, 449
Pseudobeltrania, 602
Pseudocenangium, 537
Pseudocolus, 463
Pseudodematophora, 231
Pseudographis, 156
Pseudographium, 515
Pseudomassaria, 262
Pseudomeliola, 189
Pseudomonas, 18, 21, 22
Hruginosus, 23, 27
—— Amaranti, 22
—— Araliz, 39
—— Avenz, 23, 23, 40
—— Campestris, 22, 24, 24, 25, 26,
28, 29, 31, 32, 43
—— Destructans, 26, 39, 42
— Dianthi, 22, 27
—— Fluorescens, 27, 41
—— Exitiosus, 27
— Liquefaciens, 27
—— Putrida, 27
—— Hyacinthi, 22, 25, 27, 28, 31
—— Indigofera, 13

739

Pseudomonas, Iridis, 27

—— Juglandis, 27

—— Leguminiperdus, 28

—— Levistici, 28

—— Maculicolum, 28

—— Malvacearum, 22, 29, 29

—— Medicaginis, 29, 30, 31

—— Michiganense, 30

—— Mori, 30, 43

—— Olex-tuberculosis, 34

—— Phaseoli, 22, 27, 28, $1, 31

—— Pruni, 32, 32

—— Putridus, 23

—— Putrifaciens Liquefaciens, 43

—— Radicicola, 8, 32

—— Savastanoi, 38, 46

—— Sesami, 34

—— Sps. Indet, 37

—— Stewarti, 22, 33, 34, 34

—— Syringe, 35

—— Tumefaciens, 35, 36

—— Vascularum, 27

Pseudopatella, 536

Pseudopeziza, 147, 149, 475, 539,
547, 555

—— Medicaginis, 147

—— Ribis, 148, 541

— Salicis, 148, 541

—— Tracheiphila, 148

Trifolii, 148, 148, 494, 535

Pseudophacider, 155

Pseudophacidium, 155

Pseudoplasmopara, 93

Pseudorhytisma, 156

Pseudotryblidium, 150

Pseudotsuga, 408, 416

Pseudovalsa, 280, 281

Longipes, 281

Pseudozythia, 527

Psilocary, 303

Psilocybe, 449, 451

—— Henningsii, 451

— Pennata, 452

Spadicea, 461

Psilopezia, 132

Psilospora, 534

740

Pteris, 489, 595
Pterocarpus Indicus, 426
Pterophyllus, 444
Pterula, 411
Puccinia, 355, 359, 361, 375, 390
—— Allii, 377
—— Anemones-virginianz, 389
—— Apii, 877
—— Arenarie, 387
—— Asparagi, 326, 328, 329, 330,
376, 376
—— Asteris, 389
—— Bullata, 377
—— Canne, 389
—— Castagnei, 877
—— Cerasi, 376
—— Chrysanthemi, 386
—— Cichorii, 378
—— Convallarie-digraphidis, 388
—— Coronata, 382, 383
—— Coronifera, 383
—— Cyani, 377
—— Dianthi, 389
—— Dispersa, 382
—— Endivie, 377
—— Fagopyri, 378
— Gentianz, 389
—— Gladioli, 389
—— Glumarun, 383
—— Graminis, 329, 334, 878, 379,
385
—— Air, 379
— Avene, 379
—— Phlei-pratensis, 379
—— Por, 379
—— Secalis, 379
Tritici, 379
— Granularis, 389
—— Helianthi, 386, 387
— Heterogena, 386
—— Horiana, 389
— Iridis, 389
—— Isiace, 378, 390
—— Magnusii, 376
—— Malvacearum, 328, 385, 386
—— Menthe, 378

INDEX

Puccinia, Pazschkei, 389
—— Persistens, 389
—— Phlei-pratensis, 384
—— Phragmitis, 377
—— Poarum, 386
—— Podophylli, 332
—— Porri, 377
—— Pringsheimiana, 376
—— Purpurea, 384
— Ribis, 328
—— caricis, 376
— Nigri-acute, 376
paniculate, 376
Pseudocyperi, 376
-— Rubigovera, 329, 381, 383
— Secalis, 382
Tritici, 382
Schrceteri, 389
Scille, 389
—— Simplex, 383
—— Sorghi, 329, 384, 384
—— Suaveolens, 328
—— Taraxici, 378
—— Tragopogonis, 328, 377
—— Triticina, 382
—— Tulipz, 389
— Vexans, 327
—— Viole, 388
Pucciniacee, 335, 353
Key to, 353
Pucciniastrum, 341, 346, 390, 391
—— Abieti-chamznerii, 347
—— Epilobii, 347
—— Geeppertianum, 342, 347
—— Hydrangex, 346
—— Myrtelli, 347
—— Padi, 347
Pustulatum, 347
Pucciniosita, 342
Pucciniospora, 505
Puff-balls, 395
Pulparia, 151
Pulsatilla, 333
Pumpkin, 95, 107, 247, 408, 548
Purslane, 82, 408
Pycnidium, 61

Pycnochytrium, 70, 72
—— Anemones, 72
——— Globosum, 72
Pyrenocheta, 482, 497
—— Ferox, 497

—— Oryze, 497

—— Phlogis, 497

Pyrenomycetes, 159, 165, 170, 195,

217
Pyrenopeziza, 147
Pyrenophora, 252, 262
Trichostoma, 262
Pyrenotrichum, 481
Pyroctonum, 72
Sphericum, 73
Pyronema, 116
Pyronemacez, 133, 134
Pyropolyporous Prerimosa, 430
Pyrus, 176, 183, 366, 590
—- Arbutifolia, 369
Pythiacez, 75
Pythiacystis, 75, 77, 77
—— Citrophthora, 77
Pythium, 75, 76, 76, 650
de Baryanum, 77
— Gracile, 77
—— Intermedium, 77
—— Palmivorum, 77

Q

Quercus, 127, 186, 188, 202, 220, 544

Quince, 36, 38, 130, 140, 149, 249,
267, 268, 367, 369, 371, 404, 490,
502, 515, 540, 542, 557, 569, 582

R

Rabenhorstia, 483
Rabentischia, 251

Radish, 36, 42, 81, 95, 408, 571
Radulum, 413

Ramularia, 243, 245, 589, 590
—— Armoracie, 590, 590

INDEX

Ramularia, Betz, 590
—— Coleosporii, 591
—— Cynarez, 591

—— Geranii, 591

—— Geeldiana, 591
—— Heraclei, 591
—— Lactea, 591

—— Modesta, 691
—— Narcissi, 591
—— Necator, 590
—— Onobrychidis, 691
—— Primule, 591
—— Spinacie, 590
—— Taraxaci, 590
—— Tulasnei, 244, 590
—— Vallambrose, 591
Ramulaspera, 577
Ranunculacez, 93, 320
Ranunculus, 101, 321, 375
Rape, 141, 258

741

Raspberry, 38, 245, 248, 257, 258,
270, 359, 360, 451, 503, 543, 544,

547, 581, 650
Ravenelia, 353
Red Alge, 3
Red Bud, 632
Red Cedar, 329, 431
Redtop, 310
Reessia, 68
Rehmiella, 264 276
Rehmiellopsis, 264, 276,490
Bohemica, 276
Reticulariacez, 10
Rhabdospora, 518, 519, 526
—— Coffer, 519, 525
—— Coffeicola, 519, 525
—— Oxycocci, 519, 525
—— Rubi, 519, 525
—— Theobroma, 519, 525
Rhacodium, 657
Rhacophyllus, 444
Rhagadolobium, 155
Rhamphoria, 232
Rhamus, 383
Rhinocladium, 599
Rhinotrichum, 575

742

Rhizidiacee, 67

Rhizina, 132

—— Inflata, 132, 132

Undulata, 132

Rhizinacex, 131, 132

Key to, 132

Rhizoctonia, 230, 231, 407, 408, 657,
659

—— Bete, 660

—— Crocorum, 660

—— Medicaginis, 660

—— Solani, 407, 660

—— Strobi, 660

—— Subepigea, 660

—— Violacea, 407, 660

Rhizogaster, 462

Rhizomorpha, 659

Rhizopus, 104, 105, 105

—— Necans, 106

—— Nigricans, 106

—— Schizans, 106

Rhododendron, 141, 194, 221, 258,
349, 398, 544, 559

Rhodophycee, 3

Rhombostilbella, 634, 635

— Rosz, 635

Rhopalidium, 557

Rhopographus, 217

Rhopalomyces, 570

Rhubarb, 41, 101, 377, 497, 506

Rhynchodiplodia, 510

—— Citri, 510

Rhynchomeliola, 232

Rhynchomyces, 609

Rhynchophoma, 505

Rhynchosporium, 586, 687

—— Graminicola, 587

Rhynchostoma, 232, 277

Rhytidhysterium, 161

Rhytidopeziza, 150

Rhytisma, 156, 158

—— Acerinum, 168, 159, 530

—— Punctatum, 159, 530

— Salicinum, 159, 530

~—— Symmetricum, 159

Ribes, 152, 176, 185, 188, 202, 220,

INDEX

328, 344, 351, 376, 486, 541, 542,
580, 581

Riccia, 251

Rice, 46, 213, 214, 232, 250, 257, 258,
259, 260, 276, 317, 486, 495, 497,
503, 504, 507, 512, 516, 520, 525,
535, 591, 605, 611, 613, 626, 643,
656, 661

Richardia, 408

Richonia, 189

Riccoa, 637

Rimbachia, 443

Robillarda, 505

Robinia, 235, 524

Reesleria Hypogea, 154

Reestelia, 335, 361, 363, 389, 391

—— Aurantica, 368

—— Botryapites, 370

—— Cancellata, 369

—— Cornuta, 368

—— Cydoniz, 371

—— Koreensis, 371

—— Penicillata, 367

—— Pyrata, 364, 391

—— Transformans, 369

Rosa, 36, 47, 97, 105, 176, 220, 249,
284, 359, 433, 487, 492, 503, 504,
505, 509, 516, 517, 522, 544, 555,
560, 564, 602, 631

Rosaceez, 127, 143, 330, 359, 391,
610

Roselle, 187

Rosellinia, 226, 230, 635

— Aquila, 230, 231

— Bothrina, 231

—— Echinata, 232

— Ligniaria, 232

—— Massinkii, 231

—— Necatrix, 230, 231

—— Quercina, 231

— Radiciperda, 281

Rosenscheldia, 216

Rostrella, 166

—— Coffer, 168

Rotaea, 588

Rozites, 449

INDEX
Roumegueriella, 527 Saprolegniales, 66, 74, 75
Rousseella, 216 —— Key to, 75
Rozella, 70 Sarcapodier, 595
Rubber plant, 270 Sarcina, 18

Rubus, 39, 72, 100, 176, 227, 333, 359,
361, 626

Rumex, 74, 377, 582

Ruppia, 8

Rush, 329

Rust Fungi, 64, 298, 324

Rutabaga, 27

Rutstroemia, 135

Rye, 146, 180, 200, 206, 213, 257,
258, 262, 305, 310, 317, 319, 333,
380, 382, 520, 550, 555, 587, 613

Rynchospora, 303

Sabina, 234

Saccardea, 630

Saccardia, 190

Saccardcella, 252

Saccharomycetacez, 120

—— Key to, 121

Saccharomyces, 121

Croci, 121

Saccharomycetales, 119

— Key to, 120

Saccharomycodes, 121

Saccharomycopsis, 121

Saccharum, 180

Saccoblastia, 393

Saffron, 660

Sagittaria, 315

Sainfoin, 217, 507, 591, 595

Salix, 148, 256, 344, 494, 541, 606

Salsify, 36, 42, 52, 82, 301, 328,
617

Sambucus, 185, 220, 256

Sanguisorba, 361

Santiella, 515

Sapindacezx, 127

Saponaria, 620

Saprolegniacez, 75

Sarcinella, 191, 616, 625
Sarcinodochium, 645
Sarcomyces, 151
Sarcoscypha, 135
Sarcoscypherx, 135
Sarcosoma, 151
Sarracenia, 270
Sassafras, 433

Satsuma, 604

Saxifrage, 345, 389
Scabiosa, 100, 176, 178
Scaphidium, 536
Sceptromyces, 584
Schenckiella, 189
Schinzia, 323
Schizanthus, 552
Schizomycetes, 1, 3, 13, 18
—— Key to, 18
Schizonella, 302
Schizophyllez, 443; 444
Key to, 444
Schizophyllum, 444
Alneum, 444, 445
Schizosaccharomyces, 121
Schizothyrella, 536
Schizothyrium, 156
Schweinitzia, 150
Schweinitziella, 217
Scilla, 143, 375, 389
Scirrhia, 217

Scirrhiella, 217
Sclerodermatales, 396
Scleroderris, 155
Sclerodiscus, 655
Sclerophoma, 482
Sclerospora, 82, 83, 89
Graminicola, 90, 90, 101
—— Macrospora, 89
Sclerotinia, 135, 186, 138, 568
—— Alni, 143

—— Aucuparie, 143
—— Betule, 143

743

744 INDEX

Sclerotinia, Bulborum, 143 Seiridium, 558
—— Cinerea, 137, 139, 569 Selenotila, 566
—— Crategi, 143, 569 Selinia, 198
—— Fructigena, 137, 139, 569 Sempervivum, 353
—— Fuekeliana, 139, 140, 141, 579, Senecio, 168, 333, 339

581 Sepedonium, 200, 577
—— Galanthi, 141, 581 Septobasidium, 405, 411
—— Laxa, 137, 139, 569 —— Pedicellata, 412
— Ledi, 137, 329 Septocylindrium, 588, 589
—— Libertiana, 140, 141, 141, 142, _——Areola, 589, 589

581 ——Radicicolum, 590
—— Linhartiana, 140, 569 ——Rufomaculans, 589
—— Mespili, 140 Septodothideopsis, 518
—— Nicotiane, 142 Septogleeum, 243, 556, 557
—— Oxycocci, 140, 569 Arachidis, 657
—— Padi, 140, 569 —— Cydoniz, 557
—— Rhododendri, 141 —— Fraxini, 557
—— Seaveri, 140, 569 —— Hartigianum, 557
— Trifoliorum, 143 —— Manihotis, 557
—— Tuberosa, 143 —— Mori, 249, 557
—— Umula, 137 —— Profusum, 557
Sclerotiopsis, 482 —— Ulmi, 557
Sclerotium, 659, 660 Septomyxa, 555
— Bulborum, 661 Septonema, 609
—— Cepivorum, 661 Septorella, 517
— Oryze, 661 Septoria, 243, 257, 265, 478, 517, 518
— Rhizodes, 661 — Aciculosa, 519
— Rolfsii, 660, 661, 662 —— Aisculi, 624
—— Tulipe, 661 —— Ampelina, 520
—— Tuliparum, 143, 661 —— Antirrhini, 522
Scolecopeltis ZZruginea, 195 —— Armoraciz, 522
Scolecosporium, 557 —— Avene, 520
Scolecotrichum, 602, 607 —— Azalex, 523
—— Avene, 608 —— Betz, 520
—— Fraxini, 608 . ——Canabina, 521
—— Graminis, 608, 608 —— Caragana, 524
—— Iridis, 608 —— Castanem, 524
—— Melophthorum, 608 —— Castanicola, 524
—— Muse, 608 —— Cerasina, 520
Scorias, 190 — Cercidis, 524
Scoriomyces, 641 —— Chrysanthemella, 622
Scorzonera, 305 —— Citrulli, 520 i
Secale, 180, 379 —— Consimilis, 522
Sedge, 89, 220, 329 — Cornicola, 524
Sedum, 221, 497, 522 —— Cucurbitacearum, 621 °

Seiridiella, 558 --- ——— Curvata, 524

INDEX 745

Septoria, Curvula, 520 Septoria, Tiliz, 524

—— Cyclaminis, 522 —— Tritici, 520
Dianthi, 522 —— Ulmarie, 524

—— Divaricata, 523 —— Ulmi, 221

—— Dolichi, 521 —— Varians, 522

—— Exotica, 523 —— Veronice, 524

—— Fairmanii, 523 Septosporiella, 518

—— Fragarie, 519 Septosporium, 616, 620

—— Fraxani, 624 —— Heterosporium, 620

—— Glaucescens, 520 Sequoia, 243, 632

—— Glumarum, 520 Service Berry, 191
Graminum, 520 Sesame, 34, 47

—— Hederm, 522 Setaria, 90, 209, 213, 305

—— Helianthi, 523 Shad Bush, 39

—— Hippocastani, 524 Sida, 488

—— Hydrangee, 522 Sigmoideomyces, 570

—— Iridis, 522 Sillia, 283

— Lactuce, 522 Simblum, 464

—— Limonum, 520 Sircoccus, 482

—— Leefgreni, 520 Sirodesmium, 615

—— Longispora, 520 Siropatella, 536

—— Lycopersici, 521, 522 Sirothecium, 500

—— Majalis, 623 Sirozythia, 526

—— Medicaginis, 621 Sisil, 552

—— Narcissi, 523 Sistotrema, 413

— Nicotianz, 621 Skepperia, 406

—— Nigro-maculans, 524 Slime Flux, 120

— Nodorum, 520 Slime Fungi, 3

—— Ochroleuca, 524 Slime Molds, 1

—— Oleandrina, 524 Smut Fungi, 298

—— Parasitica, 523, 624 Smuts, 64

—— Petroselini, 521 Snapdragon, 101, 492, 522, 553

Apii, 621, 521 Snowdrops, 141, 581

— Phlogis, 258, 519 Sobralia, 270

—— Pini, 162 Soft Rot, 105

—— Piricola, 246, 519 Solanaceous, 86

—— Pisi, 250, 519 Solanum, 322, 323, 408

—— Populi, 249, 519 Solenia, 406

—— Pruni, 520 Solidago, 179, 338

—— Pseudoplatani, 524 Solomon’s Seal, 488

—— Ribis, 245, 519, 619 Sorbus, 235, 255, 336, 368, 371, 607

— Rose, 522 Sordaria, 224

—— Rostrupii, 522 Sordariacer, 222, 224

—— Secalina, 520 — Key to, 224

— Sedi, 522 Sorghum, 49, 121, 221, 305, 310, 311,

— Spadicea, 524 312, 314, 384, 613

746

Sorokina, 151
Sorolpidium, 8

—— Betz, 8

Sorosphera, 6, 8

— Graminis, 8
Sorosporium, 302, 312, 312
—— Consanguineum, 312
—— Dianthi, 312

—— KEllisii, 312

—— Everhartii, 312
Sorothelia, 227

Sparassis, 412
Spathularia, 131

Speira, 615

Spelt, 206

Spermatia, 325
Spermodermia, 655
Spermogonia, 324, 325

Sphacelia, 196, 211, 212, 640, 648

—— Segetum, 213, 643

—— Typhina, 643

Sphacelotheca, 302, 303, 310

—— Reiliana, 312, 312

— Sorghi, 311, 311

Spherella, 244

Spheriacez, 222, 225

—— Key to, 225

Spheriales, 124, 195, 221, 475

— Key to, 222

Spheridium, 641

Spherioidacee, 479, 480

—— Key to, 480

—— Amerospore, 480

—— Dictyospore, 480

—— Didymospore, 480

—— Helicospore, 480

— Hyalodictyx, 480

— Hyalodidyme, 480, 505
—— Key to, 505

—— Hyalophragmie, 480, 513
— Key to, 513

—— Hyalospore, 480
— Key to, 480

—— Pheodictyz, 480, 516
—— Key to, 516

—— Pheodidyme, 480, 509

INDEX

Sphzrioidaceez, Pheodidyme, Key
to, 510
—— Phezophragmie, 480, 514
— Key to, 514
—— Phzospore, 480, 500
— Key to, 500
——— Phragmospore, 480
—— Scolecospore, 480, 517
—— Key to, 517
—— Staurospore, 480
Spherita, 68, 238
Spherocolla, 640
Spherographium, 517
Sphzromyces, 656
Spheronema, 482, 494
— Adiposum, 495
—— Fimbriatum, 494, 495
—— Oryze, 495
—— Phacidioides, 148, 494
—— Pomarum, 495
—— Spurium, 152, 495
Spheronemella, 527
Spheropeziza, 156
Spherophragmium, 454
Sphzropsdidales, 479, 564
—— Key to, 479
Spheeropsis, 284, 501
—— Japonicum, 503
— Magnolia, 503
—— Malorum, 284, 502, 502, 546
—— Mori, 603
——- Pseudodiplodia, 6038
—— Ulmi, 503
—— Vince, 603
— Viticola, 284
Sphzrosoma, 132
Spherosporium, 639
Spherostilbe, 195, 196, 198, 207
Flavida, 207
—— Repens, 207
Spherotheca, 172, 175
—— Castagnei, 115
—— Humuli, 176, 569
—— Var. Fuliginea, 176
—— Lanestris, 177
—— Mali, 184

INDEX

Sphzrotheca, Mors-uve, 176, 176

—— Pannosa, 176, 569

Sphezrulina, 236

Sphinetrina, 153

Spicaria, 201, 584, 585

—— Colorans, 205, 586

—— Solani, 586

Spicularia, 571

Spilomium, 655

Spinach, 96, 321, 487, 551, 590, 605,
611, 628, 629

Spinellus, 104

Spirea, 175, 176, 184, 336, 524,
637

Spirechnia, 354

Spirillaceze, 19

Spirilli, 13

Spirillum, Cholere-asiatice, 19

Volutans, 13

Spirodelia, 315

Spondylocladium, 609, 614

—— Atrovirens, 614, 614

Spongospora, 6, 8

—— Subterranea, 8

Sporidium, 326

Sporocybe, 630

Sporoderma, 640

Sporodesmium, 257, 615, 616, 617

Brassice, 617

—— Dolichopus, 617

Exitiosum, 258, 616

Var. Solani, 616

—— Glomerulosum, 610

—— Ignobile, 617

—— Melongenz, 617

— Mucosum, 617

—— Piriforme, 260, 616

—— Putrefaciens, 617

Scorzonere, 617

Solani Varians, 617

Sporoglena, 600

Sporonema, 274, 534, 635

— Oxycocci, 535, 535

—— Phacidioides, 148, 535

—— Platani, 274, 636

—— Pulvinatum, 536

747

Sporormia, 224
Sporormiella, 224
Sporoschismez, 609
Sporotrichella, 576
Sporotrichum, 230, 576, 577
—— Pow, 577, 578
Spruce, 145, 162, 230, 391, 418, 423,
424, 431, 432, 434, 436, 438, 440,
509, 524
Spumaria, 11
— Alba, 11
Spumariacez, 10, 11
Spurge, 544
Squash, 95, 105, 179, 247, 540, 548
Stachybotryella, 598
Stachybotrys, 598
Stachylidiee, 595
Stagonospora, 614, 514
—— Carpathica, 514
Iridis, 514
Staurocheta, 482
Staurospore, 633
Steccherinum, 414, 416
—— Ballouii, 416
Stemmaria, 630
Stemonitacez, 10
Stemphyliopsis, 592
Stemphylium, 616, 617, 617
—— Citri, 618
—— Ericoctonum, 617
Tritici, 618
Stenocybe, 153
Stereum, 405, 409
Frustulosum, 409, 410
—— Hirsutum, 409
—— Purpureum, 410
—— Quercinum, 409
Rugosum, 410
Sterigma, 298
Sterigmatocystis, 167, 310, 572, 573
— Ficuun, 573
—— Luteo-nigra, 673
Niger, 573
Stictidacer, 154
Stictis, 154, 155
—— Panizzei, 155

748

Stigmatea, 150, 236, 243, 243, 244
— Alni, 248
—— Juniperi, 243
Stigmatella, 641
Stigmella, 615
Stigmina, 608, 610, 610
— Briosiana, 610
Stilbacez, 565, 632
—— Key to, 632
—— Amerospore, 632
— Key to, 633

—— Didymospore, 632
—— Helicospore, 632
—— Hyalostilbex, 632, 633
—— Pheostilbex, 632
—— Phragmospore, 632
Stilbella, 633, 635
—— Flavida, 635
—— Nanum, 635
—— Populi, 635
—— Thee, 635
Stilbonectria, 198
Stilbospora, 558
Stilbothamnium, 630
Stilbum, 207
Stone Fruits, 139, 278, 569
Stoneworts, 3
Strawberry, 11, 52, 100, 176, 486,

494, 507, 519, 529, 542, 555, 590,

591
Streptococcus, 18
Streptothrix, 599
—— Dassonvillei, 599
Stromatinia, 137
Stropharia, 448
Strumella, 655, 656
—— Sacchari, 666
Stuartella, 226
Stypinella, 393
—— Mompa, 3938
Stypinelles, 392
Stysanus, 630, 636, 638
—— Stemonites, 637
—— Ulmaria, 637
—— Veronice, 637
Sugar-beet, 22, 36, 37, 41, 408

INDEX

Sugar Cane, 37, 47, 206, 209, 227, 228,
248, 258, 305, 374, 392, 448, 463,
464, 495, 499, 503, 512, 554, 560,
596, 606, 620, 630, 656

Maple, 415

Sulla, 277, 630

Sunflower, 179, 321, 523

Swamp Cedar, 416

Sweet Pea, 37, 268

—— Pepper, 37

— Potato, 82, 105, 204, 337, 408,
486, 492, 495, 513, 574, 597, 606,
663

— William, 508

Sycamore, 275, 498, 524, 525, 541,
546, 560, 580, 606

Sydowia, 236

Symphoricarpus, 187

Symphytum, 178

Synchytriacez, 67, 69

—— Key to, 70

Synchytrium, 70, 70

—— Endobioticum, 70

—— Papillatum, 71

—— Vaccini, 71, 71

Synsporium, 598

Synthetospora, 593

Syringa, 35, 186

Syzygites, 104

T

Tamarind, 250, 546
Tapesia, 146
Taphrina, 126

—— Aurea, 127

—— Bassei, 180

—— Bullata, 180
—— Ceerulescens, 127
—— Communis, 130 .
Crategi, 130
—— Decipiens, 180
Deformans, 127, 128, 129
—— Farlowii, 130
—— Insititie, 130

INDEX 749

Taphrina, Johonsonii, 127. Thielaviopsis, 595, 596

—— Longipes, 129 —— Ethaceticus, 228, 696

—— Maculans, 130 — Paradoxa, 596

—— Mirabilis, 129 —— Podocarpi, 597
Pruni, 128 Thiobacteriales, 19

—— Rhizipes, 129 Thistle, 328

—— Rostrupiana, 130 Thoracella, 505

—— Theobrome, 130 Thozetia, 641

—— Ulmi, 127 Thyridella, 278

Taphrinopsis, 126 Thyridium, 278

Taraxacum, 176 Thyrococcum, 658

Taxus, 192, 259, 493 — Sirakoffi, 658

Tea, 8, 231, 243, 263, 287, 403, 409, Thyronectria, 198
411, 415, 418, 438, 448, 544, 553, Thyrsidium, 553

614, 630, 635 Tiarospora, 505

Teasel, 100 Tichothecium, 236

Tecoma, 631 Tilachlidium, 633

Teleutospore, 326, 327 Tilia, 193, 202, 489, 509, 524, 545,

Telia, 326 631, 658

Terfeziacer, 165, 166 Tilletia, 301, 314, 315

Testicularia, 303 —— Feetens, 315, 316

Testudina, 167 —— Glomerulata, 315

Tetracium, 593 —— Hordei, 317

Tetracladium, 593 — Horrida, 317

Tetracoccosporium, 616 —— Panicii, 315

Tetradia Salicicola, 252 —— Secalis, 317

Tetramyxa, 6, 8 —— Texana, 316

Tetraploa, 615 —— Tritici, 316, 317

Thalictrum, 321, 389 7 Tilletiacee, 302, 314

Thallophyta, 2 Key to, 314

Thamnidiex, 105 Tilmadoche, 12

Thaxteria, 227 Timber, 415

Thecaphora, 302, 313, 313 Timothy, 24, 310, 385, 550
Deformans, 313 Titania, 280

Thecospora, 641 Titer, 593, 593

Thelephora, 406, 410 Mazxilliformis, 593

— Galactina, 411 Toad Stool, 398
Laciniata, 410, 411 Tobacco, 27, 33, 44, 45, 48, 50, 52, 69,

Thelephoracez, 402, 4056, 433 89, 143, 260, 486, 506, 521, 570,
Key to, 405 573, 581, 619, 621, 624, 627, 654

Theleporus, 449 Tolypomyria, 576

Thelocarpon, 197 Tolyposporella, 303

Theobroma, 205 Tolyposporium, 302, 318, 314

Therrya, 251 — Bullatum, 313

Thielavia, 166, 167 —— Filiferum, 314

Basicola, 167, 168 — Volkensii, 314

750 INDEX

Tomato, 21, 27, 30, 36, 41, 42, 44,47, Trichocladium, 602
52, 86, 268, 497, 522, 540, 551, 564, Trichocollonema, 517

605, 606, 623, 624, 643, 653 Trichocomacez, 165
Tomentella, 403 Trichoderma, 571
Torsellia, 483 Trichodytes, 562
Torula, 191, 595, 596, 697 Tricholoma,.123, 450, 460, 460
— Exitiosa, 597 —— Rutilans, 460
—— Spherella, 597 Saponaceum, 460
Torulex, 594, 595 Trichopeltulum, 528
— Key to, 595 Trichopezizee, 135
Toxins, 2 Trichophila, 529
Toxosporium, 557, 558 Trichopsora, 336
—— Abietinum, 558 Trichoseptoria, 517, 518
Trabutia, 276 —— Alpei, 518
Trachyspora, 354 Trichospheria, 226, 228, 228, 554,
Tracya, 315 596
Tracyella, 528 —— Sacchari, 228
Tragopogon, 178, 310, 378 Trichosporiem, 594, 598
Trametes, 417, 437 —— Key to, 598
— Pini, 401, 487 Trichosporium, 599
—— Radiciperda, 401, 431 Trichostroma, 655
—— Robinophila, 438 Trichotheca, 639
—— Suaveolens, 438 Trichothecium, 586
—— Thee, 438 Trichurus, 630
Tranzschelia, 354, 366 Tridentaria, 593
—— Punctata, 356, 357 Trientalis, 315

Trees, 193, 407, 409, 411, 426, 428, Trifolium, 168, 178, 313, 373, 374
432, 451, 452, 453, 454, 460, 568, Trigonella Ccerulea, 168

662 ; Trimmotostroma, 657, 657
~—— Coniferous, 418, 419, 424, 433, _—— Abietina, 657

440, 456 Trinacrium, 593
—— Deciduous, 414, 418, 419, 421, Triphragmium, 354, 368

425, 427, 430, 452, 454, 456 —— Ulmarie, 358, 358
—— Forest, 132, 153 Triplicaria, 655
— Fnuit, 418, 421, 439 Triticum, 180, 260, 262, 379
—— Nut, 420, 439 Trochila, 156, 157, 158, 539
—— Orchard, 419 —— Craterium, 167, 541
—— Ornamental, 421 —— Popularun, 157, 555
—— Shade, 419 Trogia, 443, 444
—— Timber, 419, 448 —— Faginea, 443
Treleasiella, 527 Tropxolum, 37, 81, 362, 621
Tremellales, 323 Trullula, 553, 554
Trichegum, 616 Vanille, 554
Trichiacer, 9 Tryblidiacer, 151, 154
Trichobelonium, 146 Tryblidiella, 150

Trichobotrys, 598 Tsuga, 229, 391, 416

INDEX

Tubaria, 449
Tuberales, 124
Tubercularia, 196, 201, 396, 639, 642,
642
— Fici, 642, 642
—— Vulgaris, 202, 642
Tuberculariacez, 565, 638
—— Key to, 638
—— Dematier, 638
—— Key to, 655°
—— Amerospore, 638, 654
—— Dictyospore, 639, 658
—— Didymospore, 638
—— Helicospore, 639
-—— Phragmospore, 639, 657
—— Key to, 657
— Scolecosporee, 639
—— Staurospore, 639
— Mucedinee, 638
—— Amerosporee, 638, 639
Key to, 639,
—— Dictyospore, 638
— Didymospore, 638
Helicosporz, 638
— Phragmospore, 638, 645
—— Key to, 645
Staurospore, 638
Tuberculina, 335, 640, 643
Tuburcinia, 315
Tulip, 143, 310, 389, 564, 661
Tumeric, 130
Tupelo, 412
Turnip, 25, 26, 36, 41, 42, 44, 46, 81,
95, 177, 568, 592, 619
Tympanis, 151
Typha, 188
Typhula, 412
—— Graminum, 412
— Variabilis, 412, 413

U

Uleomyces, 199
Ulmaria, 358
Ulmus, 188, 202, 610

751

Umbellifers, 6, 74, 91, 377, 592,
607
Uncigera, 583
Uncinula, 175, 180
—— Aceris, 182
—— Circinata, 182
—— Clandestina, 182
~—— Flexuosa, 182
Mori, 182
Necator, 181, 181 182, 569
—— Prunastri, 182
—— Salicis, 182
Uredinales, 137, 323, 394, 475, 643
—— Key to, 335
—— Biologic Specialization, 332
—— Cytology, 330
—— Form Genera, 334
—— Imperfecti, 335
— Key to, 389
—— Infection Experiments, 334
Uredinium, 325
Uredinopsis, 341, 391
Uredo, 334, 335, 389, 390, 392
— Arachidis, 392
— Aurantiaca, 392
—— Autumnalis, 392
— Kuhnii, 392
— Muelleri, 361
—— Orchidis, 392
—— Satyrii, 392
—— Tropeoli, 392
Uredospore, 327
Urobasidium, 403
Urocystis, 301, 314, 318
— Agropyri, 320
— Anemonis, 320
— Cepule, 318, 318, 319
—— Colchici, 320
—— Gladioli, 320
— Italica, 320
—— Kmetiana, 320
—— Occulta, 319, 319
—— Ornithogali, 320
—— Primulicola, 320
— Viole, 319
Urohendersonia, 515

752 INDEX

Uromyces, 355, 371, 375, 390 Usti!ago, Avene, 303, 303, 306
—— Appendiculatus, 371, 372, 373 —— Bulgarica, 305
—— Betz, 374, 374 —— Crameri, 304

—— Caryophyllinus, 328, 375 —— Cruenta, 310
—— Colchici, 375 —— Crus-galli, 305
—— Dactylidis, 374 — Esculenta, 310
—— Ervi, 375 —— Ficuum, 310

—— Erythronii, 375 Fischeri, 310

—— Fabe, 373 —— Hordei, 306, 306
—— Fallens, 374 — Levis, 306, 306
— Ficarie, 375 —— Macrospora, 306
—— Jaffrini, 375 —— Medians, 305
—— Kuhnei, 374 —— Nuda, 306, 308
—— Medicaginis, 374 —— Panici Miliacei, 310
—— Minor, 374 —— Perennans, 307
—— Pallidus, 375 —— Pheenicus, 310
—— Pisi, 329, 330, 372, 374 — Rabenhorstiana, 307
—— Poe, 376 —— Sacchari, 305
—— Scillarum, 375 —— Scorzonore, 305
— Trifolii, 373, 373, 374 —— Secalis, 310
Uromycladium, 327 —— Shiriana, 310
Urophlyctis, 73 —— Spherogena, 310
—— Alfalfe, 74 —— Strieformis, 309
—— Hemispherica, 74 —— Tragopogonis, 310
—— Kriegeriana, 74 —— Pratensis, 305
—— Leproides, 73 —— Tritici, 307, 307
—— Major, 74 —— Tulipa, 310

—— Pluriannulata, 74 —— Vaillantii, 310
—— Pulposa, 74, 74 —— Violacea, 310
— Rubsaameri, 74 —— Vrieseana, 310
—— Trifolii, 74 —— Zeer, 308, 308, 309
Uropyxis, 354 Ustulina, 285, 286
Urospora, 251 —— Zonata, 287

Urosporium, 608
Ustilaginacez, 301, 302

—— Key to, 302 Vv

Ustilaginales, 214, 299, 326, 392

— Key to, 302 Vaccinium, 184, 234, 242, 347, 397,
Ustilaginoidea, 199, 213, 214, 640, 648 548, 569

—— Virens, 214, 214, 643 Valerian, 101.

Ustilaginoidella, 199, 214, 650 Valeriana, 178

— Graminicola, 214 Valerianella, 101

—— Muszperda, 214 Valsa, 208, 277, 278

—— Cdipigera, 214 —— Ambiens, 278

Ustilago, 299, 300, 301 302, 308,310, .—— Caulivora, 278

311, 312, 313, 315 —— (Eutypa) Erumpens, 278

INDEX

Valsa (Eutypella) Prunastri, 278

Leucostoma, 278

Oxystoma, 278

Valsacere, 223, 277

—— Key to, 277

Valsaria, 279

Valsonectria, 198, 208, 208, 484

—— Parasitica, 208

Vanda, 205, 544

Vanguieria, 356

Vanilla, 204, 205, 253, 280, 375, 510,
553, 554, 607

Vegetables, 51, 105

Velutaria, 150

Venturia, 251, 253, 227

—— Cerasi, 255, 606

—— Chlorospora, 606

Crateegi, 256

—— Ditricha, 255, 607

Fraxini, 255, 606

—— Inzqualis, 253, 254, 607, 611

—— Cinerascens, 255, 607

—— Pomi, 253

—— Pyrina, 253, 607

Tremulz, 265, 607

Verbena, 176, 178, 187, 570

Vermicularia, 482, 496, 564

Circinans, 497

Concentrica, 497

Dematium, 496, 496

Denudata, 497

— Melice, 497

—— Microchata, 497

—— Polygoni-virginica, 497

—— Subeffigurata, 497

Telephii, 497

Trichella, 496

Varians, 497

Veronica, 8, 69, 523, 524, 637

Verticilliex, 566, 583

—— Key to, 583

Verticilliopsis, 583, 584

Infestans, 584

Verticilliam, 196, 200, 583, 584, 587
—— Albo-atrum, 584

Vetch, 99, 373, 409, 506

753

Vialea, 277

Vibernum, 404

Vibrio Rugula, 15

Vicia, 99, 178, 313, 372, 375, 408,
506, 582

Vigna Sinensis, 168

Vinca, 101, 488, 503

Violet, 72, 73, 96, 99, 168, 176, 320,
388, 416, 488, 507, 544, 556, 591,
599, 620, 630

Virgaria, 599

Vitis, 181, 238, 323, 620, 624

Volutella, 497, 564, 641, 644

—— Buxi, 204

—— Concentrica, 645

—— Dianthi, 646

—— Fructi, 644, 644

—— Leucotricha, 644

Volutellaria, 641

Volutina, 641

Volvaria, 449, 452

—— Bombycina, 458, 454

“
Ww

Walnut, 28, 275, 419, 421, 428, 430,
524, 555, 606

Water Lilies, 322

— Oak, 435

Watermelon, 247, 408, 490, 521, 540,
598, 629, 651

Weinmannodora, 501

Wheat, 21, 73, 90, 180, 200, 205, 206,
207, 213, 257, 258, 304, 307, 308,
316, 329, 333, 349, 379, 380, 382,
412, 491, 493, 520, 550, 571, 572,
587, 600, 613, 618

Willia, 121

Willow, 36, 44, 155, 157, 158, 159,
182, 284, 340, 342, 344, 421, 428,
433, 438, 454, 509, 530, 560, 582

Wisteria, 21

Witches Broom, 126, 130, 191, 211,
215, 330, 348, 349, 369, 648

Wojnowicia, 515

754

Woronina, 70
Woroniniella, 70
Wound Parasites, 399

x

Xanthoxylum, 188
Xenodochus, 355, 361
—— Carbonarium, 361
Xenopus, 575
Xenosporium, 615
Xerotus, 445
Xylariacez, 224, 284
—— Key to, 285
Xylarier, 285
Xylocladium, 637
Xylostroma, 657, 663
Xylotroma, 659, 633

Y

INDEX

Yeasts, 120, 121
Yew, 249
Ypsilonia, 482
Yucca, 503

Zea, 384

Zigneella, 227

Zingiber, 46, 52, 130
Zinnia, 141

Zizania, 310

Zopfia, 189

Zopfiella, 189

Zukalia, 190, 191

—— Stuhlmanniana, 191
Zygochytriacee, 67
Zygodesmus, 599

— Albidus, 599
Zygomycetes, 66, 101, 114
—— Key to, 102
Zygorbynchus, 104
Zygosaccharomyces, 121
Zythia, 527

—— Fragariz, 527

HE following pages-contain advertisements of books
by the same author or on kindred subjects.

Diseases of Economic Plants

By F. L. STEVENS, Pu.D.
Professor of Botany and Vegetable Pathology of the North Carolina
College of Agriculture and Mechanic Arts and Biologist of the Agri-
cultural Experiment Station

AND

J. G. HALL, M.A.
Assistant in Vegetable Pathology in the North Carolina Agricultural
Experiment Station

Cloth, illustrated, 12mo, 523 pp., $2.00 net; by mail, $2.19

Students of Plant Diseases are naturally divided into two categories.
First: Those who wish to recognize and treat diseases, without the bur-
den of long study as to their causes; Second: Those who desire to study
the etiology of diseases, and to become familiar with the parasites which
are often their cause.

The present book is designed to meet the needs of the first of these
two classes of readers, and particularly for such students in the Agri-
cultural Colleges and Agricultural High Schools. It indicates the chief
characteristics of the most destructive plant diseases of the United States
caused by cryptogamic parasites, fungi, bacteria, and slime moulds, in
such a way that reliable diagnoses may be made, and fully discusses the
best methods of prevention or cure for these diseases.

In this volume only such characters are used as appear to the naked
eye or through the aid of a hand lens, and all technical discussion is
avoided in so far as is.possible. No consideration is given to the causal
organism, except as it is conspicuous enough to be of service in diagnosis,
or exhibits peculiarities, knowledge of which may be of use in prophylaxis.

While, in the main, non-parasitic diseases are not discussed, a few of
the most conspicuous of this class are briefly mentioned, as are also
diseases caused by the most common parasitic flowering plants.

A brief statement regarding the nature of bacteria and fungi and the
most fundamental facts of Plant Physiology are given in the appendix. .
Nearly 200 excellent illustrations greatly increase the practical value of

the book.
CONTENTS

Preface—Introductory—Historical—Damage Caused by Plant Dis-
eases—Symptoms of Disease—Prevention or Cure of Plant Diseases—
Public Plant Sanitation—Fungicides—Spraying Machinery—Cost of
Spraying—Profits from Spraying—Soil Disinfection—General Diseases—
Diseases of Special Crops: Pomaceous Fruits; Drupaceous Fruits; Small
Fruits; Tropical Fruits; Vegetable and Field Crops. Cereals: Cereal
Smuts, General; Cereal Rusts, General; Anthracnose of Cereals; Special
Diseases of Cereals; Forage Crops; Fiber Plants; Trees and Timber: Gen-
eral Diseases, Special Hosts; Ornamental Plants—Appendix—Index.

PUBLISHED BY
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Publishers 64-66 Fifth Avenue New York

Diseases of Cultivated Plants and Trees

By GEORGE MASSEE
Assistant Keeper, Herbarium, Royal Botanic Gardens, Kew. Author of
“British Fungus Flora,”’ ‘“Text-Book of Plant Diseases,” ‘Plant
World” and “Text-book of Fungi”

Cluth, illustrated, 8v0, xii +602 pp., indexes, $2.25 net; by mail, $2.44

A practical work, embodying the results of the researches of
scientists in all parts of the world, prepared by a writer who,
through long continued personal investigations and experiments,
not only represents accurately the views of others but gives rea-
sons for the statements which he himself advances.

This volume takes the place of the author’s “Text-book of Plant
Diseases,’”’ the issue of which has become exhausted, but follows
somewhat different lines, and covers a much wider field. In addi-
tion to a discussion of the causes and cure of the various fungi and
parasitic diseases, there are chapters on Wounds (caused by prun-
ing, wind, snow, etc.); Drought; Injuries due to Frost and Hail;
Injury by Smoke, Acid, Fumes, Gas, etc.; Injuries caused by
Animals and Birds; The Bacteriology of the Soil; and other val-
uable topics.

The treatment though technical, is sufficiently concise and clear
to be easily comprehended by the least scientific.

BY THE SAME AUTHOR

A Text-Book of Fungi

Illustrated, 8v0, $2.00 net

This book supplies not only botanical information as to the various
fungi which attack useful and ornamental plants, but gives the gardener
and orchardist a manual for the cure and prevention of these pests. The
author is a specialist of wide reputation and one of the assistants at the
Kew Botanical Gardens.

PUBLISHED BY
THE MACMILLAN COMPANY

‘Publishers 64-66 Fifth Avenue New York

Plant Physiology

By

B. M. DUGGAR
Professor of Plant Physiology in Cornell University

Cloth, 12mo, $1.60 net

FROM THE PREFACE

“The engineer who does not understand his machine cannot expect
to get effective work out of it. He should know its intimate structure,
what work it can perform under all conditions, and how it may be
controlled. In the same way the plant producer who knows the struc-
ture of the plant and its behavior is provided with the means of inter-
preting the effects of conditions upon the organism. The plant is a
delicate physical, chemical, and living mechanism and as such is
responsive to practically all kinds of stimuli.” r

In this book the author discusses the life relations of plants and
crops from a fundamental point of view. The important physio-
logical activities of the plant are demonstrated experimentally,
and the requirements of the agricultural crop examined as far as
practicable from the point of view of physiology. The main agri-
cultural and horticultural practices of the crop grower, so far as
they involve the plant itself, are reviewed, either with the purpose
of explaining the scientific principles involved or of offering an
opinion on them. Laboratory and field experiments and general
observations are drawn on in these discussions. Some of the special
topics that are considered are as follows: The relation of the plant
and the crop to water; the relation to soil nutrients, stimulants, and
inhibiting agents; the relation to light and air; the relation to heat
and cold; the relation to the disease environment.

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NOW READY FOURTH ENGLISH EDITION 8 VO. $5.00 NET

A. Text-Book of Botany

By Dr. EDWARD STRASBURGER Dr. LUDWIG JOST
Professor in the University of Bonn Professor in the University of
Strasburg
Dr. HEINRICH SCHENCK Dr. GEORGE KARSTEN
Professor in the Technical Academy of Professor in the University of
Darmstadt Halle

Fourta Encutsh Eprrion, REVISED WITH THE TENTH GERMAN EDITION

By W. H. LANG, M.B., DS8c., F.RS.
Barker Professor of Cryptogamic Botany in the University of Manchester

With 782 illustrations, in part coloured

PREFATORY NOTE é

The first edition of the English translation of this text-book was the work of
Dr. H. C. Porter, Assistant Instructor of Botany, University of Pennsylvania.
The proofs of this edition were revised by Professor Seward, M.A., F.R.S. The
second English edition was based upon Dr. Porter's translation, which was revised
with the fifth German edition. The present edition has been similarly revised
throughout with the tenth German edition. Such extensive changes, including the
substitution of completely new sections on Physiology and Phanerogamia, have
however been made in the work since it was first translated, and in the third and
fourth English editions, that it seems advisable to give in outline the history of the
English translation instead of retaining Dr. Porter's name on the title-page.

The official plants mentioned under the Natural Orders are those of the British
Pharmacopeeia instead of those official in Germany, Switzerland, and Austria,
which are given in the original. .. .

PRESS NOTICES OF FORMER EDITIONS

“The translator has been most successful in his work, the book reading as though
originally written in English. . . . One of the best, if not the best, text-book ex-
tant.”’—Nature.

“The whole style of the book is admirable; the type, illustrations, and general
arrangement leave nothing to be desired, while the coloured pictures of typical
eryptogams and phanerogams, which are scattered throughout the text, are life-like
in their beauty. . . . We have not the slightest doubt that this text-book will be
tons regarded as a standard work, and we wish it all the popularity it deserves.""—

nowledge.

“It would be not doing justice to the present book if we did not place it in the
foremost rank. . . . We may cordially commend the book as one worthy to take a
place on the shelves of the expert and on the work-table of the student.” — Atheneum.

“This work includes the most essential knowledge of several special books, it is
almost a library in itself, and is moreover, a guide to botanical literature. It is well
worth its price, and should be looked upon as a necessary possession.” —Garden

PUBLISHED BY
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Household Bacteriology

By

ESTELLE D. BUCHANAN, M.S.
Recently Assistant Professor of Botany, Iowa State College

AND

ROBERT EARLE BUCHANAN, Ps.D.
Professor of Bacteriology, Iowa State College, and Bacteriologist of the
Iowa Agricultural Experiment Station

Cloth, 8vo, zv+536 pp., index, $2.26 net

The word Household is used as an extension rather than a limitation of
the title. In a thoroughly scientific manner the authors treat the subject-
matter of general as well as of household bacteriology and include, there- °
fore, the true bacteria as well as the yeasts, molds, and protozoa. The
volume is, therefore, a general textbook of micro-biology in which special
attention is given ‘to those problems which are of particular interest to the
student of household science. The main divisions of the book treat (1) the
micro-organisms themselves, (2) fermentations with special reference
to those affecting foods, (3) the relations of bacteria and other micro-
organisms to health. A fully illustrated key (comprising 37 pages) to the
families and genera of common molds, supplements the unusually ex-
tended discussion of the morphology and classification of yeasts and
molds, and makes possible the satisfactory identification of all forms or-
dinarily encountered by the student. The work embodies the results of
the most recent researches. The book is exceptionally well written, the
different topics are treated consistently and with a good sense of propor-
tion. While concise in statement, it is thorough in method and scope. It
is, therefore, well adapted for use as a text not only for students of household
science, but also for those to whom it is desired to present the science of
bacteriology from an economic and sanitary rather than from a strictly
medical point of view.

“The book is a concisely written work on micro-biology, a branch of
economic science that the public is beginning gradually to understand,
has important relationship to the total welfare and prosperity of the com-
munity. . . . The manual can be recommended as a very good elementary
bacteriology. It comprises about all there is of practical domestic value.”

—Boston Advertiser.

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