flattened, subreniform, stipitate or subsessile; the wall a thin
violaceous or brownish membrane, rugulose, thickly covered with small
white roundish nodules of lime, similar to those in the capillitium.
Stipe short, brown or blackish at least below, sometimes pallid or
grayish above, longitudinally rugulose. Capillitium of slender tubules,
forming a loose net-work; the nodules of lime small, white, very
numerous, roundish or ellipsoidal, often confluent end to end. Spores
irregularly globose or angular, minutely warted, dark violaceous, 11-14
mic. in diameter.
Growing on old stalks and leaves of _Zea mays_. Sporangium variable,
.6-1.0 mm. in breadth, the stipe 1 mm. or less in length; the lime
nodules about the thickness of the spores. According to Saccardo this
species is the same as _Physarum nephroedium_ Rost.
9. PHYSARUM POLYCEPHALUM, Schw. Sporangia confluent into a subspheric
gyrose-complicate head, composed of several to many laterally
compressed, irregular, simple sporangia; the wall a thin, pellucid
membrane, covered by a thin layer of minute scales of lime, white to
yellow or greenish-yellow Stripes thin, flat, weak, and often prostrate,
pale yellow, more or less connate, arising from a thin hypothallus.
Capillitium of slender tubules forming a loose, irregular network, more
or less expanded at the angles: the lime-nodules white or yellow, small,
fusiform or by confluence elongated and sometimes branched. Spores
globose, very minutely warted, violaceous, 8-10 mic. in diameter.
Growing on old bark, wood, leaves, etc. The sporangia rarely simple,
usually confluent into a head of from four or five to fifteen or twenty,
and sometimes more, simple sporangia; the stipes variable in length,
long or short, rarely wanting. The gray form is _Didymium polymorphum_
Mont., the yellow-green form _D. gyrocephalum_ Mont. Sprengel considered
this species the same as _Physarum compactum_ Ehr., and it appears under
this name in Schweinitz's _North American Fungi_; but Fries, who had
seen specimens of both, disposed of them differently.
10. PHYSARUM DIDERMOIDES, Pers. Sporangia obovoid-oblong, stipitate,
growing close together on a white membranaceous common hypothallus; the
wall with a thick, white, outer layer of lime, easily crumbling and
falling away, leaving the sporangium dark gray; the inner membrane
rather thick and firm, violaceous, with a closely adherent layer of
granules of lime. Stipes very short, white, thin, and weak, each formed
by a bit of membrane arising from the hypothallus. Capillitium a loose
net-work of slender threads, bearing numerous roundish or irregular
white nodules of lime. Spores irregularly or angularly globose, minutely
warted, dark violaceous, 12-15 mic. in diameter.
Growing on wood, leaves, grass, etc. Sporangia .6-1.2 mm. in length by
.4-.6 mm. in thickness, the stipe shorter than the sporangia. _Spumaria
licheniformis_ Schw., belongs here. This is a truly abnormal species of
_Physarum_, so much so that Fries, in the _Summa Veg. Scand._ placed it
by itself in a separate genus, _Claustria_.
_B. Sporangia sessile._
11. PHYSARUM CONFLUENS, Pers. Plasmodiocarp roundish, oblong or
elongated, and by confluence branched and reticulate; the wall a thin,
violaceous membrane, rugulose, with a thin, closely adherent layer of
minute granules of lime, over which are scattered small, white, roundish
nodules, which sometimes accumulate into a thick, pulverulent coat.
Capillitium a loose net-work of tubules, widely expanded at the angles;
the nodules of lime small, white, very numerous, roundish or
ellipsoidal, by confluence elongated and irregular. Spores irregularly
globose, minutely warted, dark violaceous, 9-11 mic. in diameter.
Growing on old wood, bark, leaves, etc. Plasmodiocarp .4-.5 mm. in
thickness, varying from roundish to much elongated, creeping and
reticulate. The sporangium before dehiscence is gray, whence Link's
name, _Physarum griseum_; the loose pulverulent coating of lime easily
falls away, leaving the sporangium dark colored, whence Rostafinski's
name, _Physarum lividum_. The amount of lime on the wall and in the
capillitium is variable.
12. PHYSARUM LUTEOLUM, Peck. Sporangia small, subglobose, sessile,
closely gregarious; the wall a thin membrane, covered by a layer of
small scales of lime, yellowish, inclining to tawny, in color, rupturing
irregularly. Capillitium of slender tubules, forming a dense net-work of
small meshes, scarcely expanded at the angles; the nodules of lime
small, numerous, yellowish, roundish, or ellipsoidal. Spores globose,
nearly smooth, violaceous, about 10 mic. in diameter.
Growing on living leaves of _Cornus canadensis_, Adirondack Mountains,
New York. I have not seen a specimen of this _Physarum_, but from
Professor Peck's description and figure it seems to be a unique species.
13. PHYSARUM THEJOTEUM, Fr. Sporangia very small, sessile, on a thin
membranaceous hypothallus, closely crowded together and more or less
connate, subobovoid or oblong, irregular from mutual pressure; the wall
a thin violaceous membrane, closely covered with a thin layer of small
irregular scales of lime, tawny or yellowish tawny in color, breaking up
irregularly about the apex. Capillitium a loose irregular net-work of
slender threads, more or less expanded at the angles; the lime nodules
small, tawny or yellowish, not numerous, ellipsoidal or fusiform, by
confluence elongated and irregular. Spores globose, even, violaceous,
6-7 mic. in diameter.
Growing on old wood, mosses, etc. Sporangia .2-.4 mm. in diameter at the
apex, densely packed and their walls grown together, approaching the
aethalioid structure; the lime-nodules from one to two or three times
the diameter of the spores in thickness. I have described my specimens,
which are abundant, very carefully, and judge them to be referable to
this species; if so, they show that the species should be kept apart
from _Physarum virescens_. _Didymium nectriaeforme_ B. & C., is evidently
this same species.
14. PHYSARUM LATERITIUM, B. & R. Sporangia sessile, irregularly globose
and gregarious, or by confluence more or less elongated and
plasmodiocarp; the wall a thin violaceous membrane, rugulose and
iridescent, closely covered with small irregular scales of lime, from
testaceous or brick-red to bright red in color. Capillitium a dense
irregular net-work of tubules, much expanded at the angles; the nodules
of lime small, very numerous, roundish or angular, whitish or yellowish,
sometimes tinged with red granules. Spores globose, very minutely
warted, violaceous, 8-10 mic. in diameter.
Growing on old wood, sticks, leaves, etc. Sporangia .4-.6 mm. in
diameter, by confluence sometimes much elongated; the lime-nodules two
or three times the diameter of the spores in thickness. _Didymium
lateritium_ B. & R. _Physarum inequale_ Peck, is the same species.
Sec.2. SAXELLA. Lime in the capillitium abundant, the nodules large,
angular or irregular, with pointed lobes and branchlets.
_A. Sporangia stipitate._
15. PHYSARUM IMITANS, Racib. Sporangium depressed-globose, the base
flattened or umbilicate, stipitate, erect or cernuous; the wall a thin
violaceous membrane, with a closely adherent layer of minute granules,
over which are scattered rather large, roundish or irregular white
scales of lime, splitting from the apex downward into a few irregular
segments. Stipe short, thick at the base and tapering upward,
longitudinally rugulose, from gray to brown or blackish, especially
below. Capillitium a loose irregular network of tubules, widely expanded
at the angles; the nodules of lime white, numerous, large, irregular,
with pointed angles and lobes. Spores globose, very minutely warted,
violaceous, 8-9 mic. in diameter.
Growing on old wood, mosses, etc. Sporangium .4-.5 mm. in diameter, the
stipe about the same length or a little longer. The species
superficially resembles the gray form of _Physarum nutans_, and quite
likely is constantly overlooked on this account. Although I am not able
to verify my reference, yet my specimens answer so well to the
description of Raciborski that I am unwilling to invent a new name.
16. PHYSARUM ORNATUM, Peck. Sporangium globose or depressed-globose,
stipitate; the wall a thin yellowish membrane, covered with minute
granules and small irregular scales of lime, yellow to orange in color.
Stipe short, erect, blackish-brown, black at the base, longitudinally
plicate, rising from a small hypothallus. Capillitium of tubules forming
a rather dense net-work, with wide expansions at the angles; the nodules
of lime large, numerous, yellow, irregular, sometimes confluently
branched and reticulate. Spores globose, minutely warted, dark
violaceous, 10-12 mic. in diameter.
Growing on old wood, bark, mosses, etc. Sporangium about .5 mm. in
diameter, the stipe about the same length or shorter. _Physarum oblatum_
McBride, can not be distinguished from this. Specimens of this species
in the herbarium of Schweinitz are labeled _Physarum sulphureum_; this
is without doubt a mistake.
17. PHYSARUM GRAVIDUM, Morgan, n. sp. Sporangium depressed-globose, the
base umbilicate, stipitate; the wall a thin, violaceous membrane,
brownish at the base, with a thin coat of small, white scales and minute
granules of lime. Stipe long, erect, brown or reddish-brown, darker
below, tapering upward, expanding at the base into a small hypothallus.
Capillitium of slender tubules forming a loose net-work, more or less
expanded at the angles and for the most part filled with lime; the
nodules white, slender, much elongated and branched, with pointed lobes
and branchlets. Spores globose, very minutely warted, dark violaceous,
11-13 mic. in diameter.
Growing on old stalks of _Zea mays_. Sporangium .5-.6 mm. in diameter,
the stipe about twice this length. The lower part of the capillitium is
sometimes entirely filled with lime, so that the species approaches
Badhamia in the structure of its capillitium.
18. PHYSARUM LEUCOPUS, Link. Sporangium globose, the base slightly
flattened, stipitate; the wall a thin, violaceous membrane, with a
white, pulverulent outer coat of minute granules of lime. Stipe short,
thick, erect, snow-white, longitudinally rugulose, tapering upward,
expanding at the base into small, white hypothallus. Capillitium a loose
net-work of tubules, with wide expansions at the angles; the nodules of
lime large, white, numerous, irregularly lobed and branched. Spores
globose, very minutely warted, violaceous, 8-10 mic. in diameter.
Growing on old wood, leaves, etc. Sporangium .3-.4 mm. in diameter, the
stipe about the same length as the diameter. Our specimens are a smaller
form than the European, with smaller and smoother spores. Superficially
the species resembles _Didymium squamulosum_, and it is _Didymium
leucopus_ of Fries, S. M.
19. PHYSARUM GLAUCUM, Phillips. Sporangium globose, or the base slightly
depressed, stipitate; the wall a thin, violaceous membrane, covered with
minute, white granules and small roundish or irregular scales of lime.
Stipe short, stout, erect, black, longitudinally wrinkled, expanding at
the base into a small hypothallus. Capillitium of much-flattened
tubules, forming a loose net-work, widely expanded at the angles; the
nodules of lime numerous, large, white, irregular, with pointed angles
and lobes. Spores globose, very minutely warted, dark violaceous, 12-14
mic. in diameter.
Growing on old leaves: California. Sporangium .5-.7 mm. in diameter,
the stipe not longer than the diameter. This is quite a robust species,
both externally and in the broad, flat tubules of the capillitium.
20. PHYSARUM RELATUM, Morgan, n. sp. Sporangium globose, the base
umbilicate, stipitate, often cernuous; the wall a thin, violaceous
membrane, rugulose and iridescent, covered with small, roundish or
irregular white scales of lime. Stipe long, erect or inclined, rising
from a thin hypothallus, tapering upward, white or cream color to
ochraceous. Capillitium a dense net-work of tubules, more or less
expanded at the angles, and almost entirely filled with white granules
of lime, leaving only here and there short, slender empty spaces. Spores
globose, nearly smooth, violaceous, 8-9 mic. in diameter.
Growing on old wood. Sporangium .5-.6 mm. in diameter, the stipe about
twice this length. The capillitium is rigid, with the abundance of lime
almost as in the genus _Badhamia_. Superficially the species much
resembles _Cytidium globuliferum_ or _Physarum compactum_, but the
disposition of the lime on the wall and in the capillitium is altogether
different.
21. PHYSARUM AURISCALPIUM, Cke. Sporangia subglobose, depressed,
substipitate; the wall a hyaline membrane with a thin, closely adherent
layer of minute granules of lime, over which are scattered large,
irregular, orange-red scales of lime. Stipe very short, sometimes almost
obsolete. Capillitium of tubules forming a loose net-work, with widely
expanded angles, and mostly filled with orange granules of lime, only
here and there short, slender, empty spaces. Spores globose, minutely
warted, dark violaceous, 11-13 mic. in diameter.
Growing on rotten wood; South Carolina, Ravenel. Sporangia .6-.8 mm. in
diameter, the stipe very short. Described in _Annals of the Lyceum of
Natural History of New York_, June, 1877. So fine a species ought to be
found again. Cooke's specimen was examined by Lister, _Mycetozoa_, p.
61.
EXPLANATION OF PLATE XIV.
Fig. 56.--Craterium minimum, B. & C. _a._ Sporangia x 5. _b._ Sporangium
with lid x 90. _c._ Capillitium and spores x 500.
Fig. 57.--Craterium maydis, Morgan. _a._ Sporangia x 5. _b._ Sporangium
x 90. _c._ Capillitium and spores x 500.
Fig. 58.--Physarum obrusseum, B. & C. _a._ Sporangia x 5. _b._
Sporangium x 90. _c._ Capillitium and spores x 500.
Fig. 59.--Physarum connexum, Link. _a._ Sporangia x 5. _b._ Sporangium x
90. _c._ Capillitium and spores x 500.
Fig. 60.--Physarum polycephalum, Schw. _a._ Sporangia x 5. _b._
Sporangia x 90. _c._ Capillitium and spores x 500.
Fig. 61.--Physarum lateritium, B. & C. _a._ Sporangia x 5. _b._
Sporangia x 90. _c._ Capillitium and spores x 500.
Fig. 62.--Physarum imitans, Racib. _a._ Sporangia x 5. _b._ Sporangium x
90. _c._ Capillitium and spores x 500.
Fig. 63.--Physarum relatum, Morgan. _a._ Sporangia x 5. _b._ Sporangia x
90. One divested of the wall and showing the rigid capillitium. _c._
Capillitium and spores x 500.
[Illustration: The Journal of the Cin. Soc. Natural History.
VOL. XIX. PLATE XIV.
MORGAN ON MYXOMYCETES.]
_B. Sporangia sessile._
22. PHYSARUM PLUMBEUM, Fr. Sporangia small, globose or obovoid, sessile,
on a narrow base, gregarious, sometimes close but seldom confluent; the
wall a thin violaceous membrane, with a very thin layer of small white
scales and minute granules of lime, sometimes naked. Capillitium a loose
net-work of slender tubules, with slight expansions at the angles; the
nodules of lime white, numerous, more or less elongated, irregularly
lobed and branched. Spores globose, even, violaceous, 7-9 mic. in
diameter.
Growing on old leaves, sticks, etc. Sporangia .3-.4 mm. in diameter,
quite regular in shape, attached by a narrow base, sometimes by a mere
point, rarely confluent. The lime on the wall of the sporangium is
rather scanty, sometimes altogether absent, and the nodules of lime in
the capillitium are rather small. The species is figured by Micheli N.
P. G. Tab. 96, Fig. 9. It is named by Fries S. M., III, p. 142. It is
figured again by De Bary, _Die Mycetozoen_, Tafel I.
23. PHYSARUM ATRUM, Schw. Sporangia sessile, subglobose or oblong, by
confluence, more or less elongated, bent or flexuous and branched; the
wall a thin violaceous membrane, rugulose, covered by a wrinkled and
reticulate layer of white granules of lime, which sometimes become thin
or disappear. Capillitium a loose net-work of tubules, more or less
expanded at the angles; the nodules of lime white, numerous, large,
irregularly lobed and branched. Spores globose, very minutely warted,
violaceous, 8-10 mic. in diameter.
Growing on old leaves, bark, grasses, etc.; apparently the most common
of these three cinereous species. Sporangia .3-.5 mm. in thickness, some
of them roundish or oblong, others elongated to several millimeters. The
sporangium is often elegantly reticulate as observed by Schweinitz even
when the lime is quite scanty. In Saccardo's _Sylloge_ Berlese changed
the name to _Physarum reticulatum_, but this is unnecessary, as the
_Physarum atrum_ of Fries is not a Myxomyces.
24. PHYSARUM CINEREUM, Batsch. Sporangia large, subglobose, sessile,
gregarious, sometimes close and confluent; the wall a thin violaceous
membrane, with a closely adherent layer of minute granules, over which
are scattered irregular white scales of lime. Capillitium of tubules
forming a loose net-work, with wide expansions at the angles; the
nodules of lime numerous, white, very large, with pointed angles and
lobes, by confluence often branched and reticulate, and occasionally
forming a pseudo-columella in the center of the sporangium. Spores
globose, minutely warted, dark violaceous, 10-13 mic. in diameter.
Growing on old wood, leaves, etc. The sporangia .4-.6 mm. in diameter,
more or less irregular. The great abundance of lime in the capillitium
and the large distinctly warted spores distinguish this species.
_Physarum cinereum_ of Persoon's Synopsis, _Didymium cinereum_ of Fries'
_Systema_. The only American specimens I have of this species are from
Iowa (_McBride_) and from Nebraska (_Webber_).
25. PHYSARUM VIRESCENS Ditm. Sporangia large, subglobose, irregular and
unequal, sessile, gregarious, sometimes crowded, but not often
confluent; the wall a thin membrane, violaceous, or in places yellowish,
with a dense layer of yellow or greenish-yellow scales and granules of
lime. Capillitium a loose net-work of tubules, with wide expansions at
the angles; the nodules of lime large, numerous, yellow or
greenish-yellow, more or less elongated, lobed, and branched. Spores
globose or somewhat irregular, very minutely warted, violaceous, 9-11
mic. in diameter.
Growing on old leaves, mosses, etc. Sporangia .5-.8 mm. in diameter,
occasionally by confluence more elongated. Though found in all parts of
the country, the species seems rare. This is not the _Physarum
virescens_ described by Rostafinski.
26. PHYSARUM RUBIGINOSUM, Fr. Sporangia subglobose, sessile, gregarious;
the wall a thin hyaline membrane, thickly covered with large irregular
scales of lime, orange to red or dark red in color, breaking up
irregularly. Capillitium of hyaline tubules, forming a loose irregular
net-work, more or less expanded at the angles; the nodules of lime
large, angular, and irregular, sometimes confluent, orange to dark red
in color. Spores globose, very minutely warted, dark violaceous, 9-11
mic. in diameter.
Growing on old wood, leaves, mosses, etc. Sporangia .6-.8 mm. in
diameter. _Physarum fulvum_ Fries S. M., III, p. 143. A rare species. It
should not be confounded with _Physarum lateritium_.
27. PHYSARUM SERPULA Morgan, _n. nom._ Plasmodiocarp roundish or oblong
to much elongated, bent, annular and flexuous, sometimes by confluence
branched and reticulate; the wall a firm yellowish membrane, with a
thin, rough, closely adherent coat of granules of lime, dull ochre to
lemon-yellow and orange in color. Capillitium a dense net-work of
tubules, for the most part filled with lime, only here and there short,
slender, empty spaces; the nodules large, numerous, white or yellow,
angular and with pointed lobes and branchlets. Spores globose, minutely
warted, dark violaceous, 9-11 mic. in diameter.
Growing on leaves, bark, lichens, etc. Plasmodiocarp .3-.4 mm. in
thickness and of varying length. This species is in the herbarium of
Schweinitz, at Philadelphia, with the name _Physarum reticulatum_; it is
described by George Massee as _Physarum gyrosum_; by Lister it is
incorporated with several other species under _Badhamia decipiens_.
28. PHYSARUM CONTEXTUM, Pers. Sporangia sessile and closely crowded
together, roundish or more or less elongated, flexuous and complicate,
the apex plane or impressed; the wall a firm yellowish membrane, covered
by a thick pulveraceous layer of lime, white, ochraceous or yellow,
easily crumbling and breaking up. Capillitium a loose net-work of
tubules, much expanded at the angles; the nodules of lime very large,
white or yellow, numerous, angular, and irregular, by confluence lobed
and branched, sometimes massed together in the center of the sporangium.
Spores globose, minutely warted, dark violaceous, 10-13 mic. in
diameter.
Growing on bark, leaves, mosses, etc. Sporangia with a width of .3-.5
mm. and varying in length from .5 mm. to 1 or 2 mm. The sporangia are
often so much crowded as to appear to be grown together. _Diderma
ochroleucum_ B. & C. belongs to this species. _Physarum conglomeratum_
Fr. is a closely related species, with smaller and smoother spores. I
have not met with this.
29. PHYSARUM DIDERMA, Rost. Sporangia large, irregularly globose or
oblong, sessile, but without a hypothallus, closely crowded together and
sometimes confluent. The wall composed of two distinct and separate
layers; the outer a thick, uneven, crustaceous, snow-white layer of
lime; the inner a thin, violaceous membrane, cinereous from the adherent
granules of lime, or free from them, and iridescent. Capillitium of
tubules forming a loose net-work, with wide expansions at the angles;
the nodules of lime numerous, snow-white, large, irregular, with pointed
angles and lobes, sometimes confluent in the center of the sporangium.
Spores globose, minutely warted, dark violaceous, 9-10 mic. in diameter.
Growing on wood, bark, and mosses. Sporangia .8-1.0 mm. in diameter,
more or less irregular. The wall of the sporangium is exactly like that
of certain species of _Diderma_. This species must be rare, as I have
met with it but twice in ten years, and I am not aware that it has ever
been found by any one else.
VIII. FULIGO, Haller. Aethalium a compound plasmodiocarp; the component
sporangia branching and anastomosing in every direction, complicate and
grown together; the walls of the sporangia a thin membrane, coated with
minute, roundish granules of lime. Capillitium of tubules forming a
net-work of irregular meshes, more or less expanded at the angles, the
tubules containing in greater or less abundance irregular nodules of
lime. Spores globose or sometimes ellipsoidal, violaceous.
The genus is readily distinguished from _Spumaria_ by the round granules
of lime upon the walls of the sporangia.
Sec.1. AETHALIUM, Link. Aethalia large; the lime in the capillitium scanty,
the nodules small, ellipsoidal, or fusiform.
_a. Aethalium with a thick fragile common cortex._