.5-.7 mm. in diameter, the stipe from once to twice as long. As here
defined, the species includes _Physarum aurantium_ var. _rufipes_ A. &
S., and _Physarum aureum_ var. _chrysopus_ Lev, which I am unable to
keep separate; the variation in size of the spores is not in
correspondence with the variations in color of the sporangia. _Physarum
pulchripes_ Peck, and _Physarum petersii_ B. & C., mostly belong here.
The bright orange colors become dull or tawny with age and exposure to
the weather.
4. CYTIDIUM RAVENELII, B. & C. Sporangium globose, stipitate; the wall a
thin pellucid membrane, covered with small scales of lime, from gray or
drab to pale umber in color, breaking up at maturity and falling away.
Stipe variable in length, concolorous with the sporangium or darker
below, tapering upward and entering the sporangium as a short obtusely
conical columella. Capillitium of tubules, forming a dense net-work of
very small meshes, with slight expansions at the angles; the
lime-nodules small, numerous, ellipsoidal or obtusely angular, gray or
drab to pale umber in color. Spores globose, nearly even, pale
violaceous, 7-9 mic. in diameter.
Growing on old wood, mosses, etc. Sporangium about .5 mm. in diameter,
the stipe once to twice this length. The species as here described
includes _Didymium ravenelii_ B. & C., _Physarum simile_ Rost., and
_Physarum murinum_ Lister.
5. CYTIDIUM GLOBULIFERUM, Bull. Sporangium globose, the base sometimes
flattened or slightly umbilicate, stipitate; the wall a thin, pellucid
membrane, covered with small scales of lime, white, cream-colored, or
sometimes pinkish, breaking up and falling away at maturity. Stipe
variable in length, white or smoky-white, usually darker below, rising
from a thin hypothallus, tapering upward and entering the sporangium as
a short obtuse or conical columella. Capillitium of slender tubules,
forming a dense, persistent net-work of very small meshes, more or less
expanded at the angles; the nodules of lime variable in size, numerous,
white, roundish, ellipsoidal or obtusely angular. Spores globose, nearly
even, pale violaceous, 7-9 mic. in diameter.
Growing on old wood, bark, mosses, etc. A very common and abundant
species. Sporangium .5-.6 mm. in diameter, the stipe from once to two or
three times this length. The lime nodules in the capillitium are
sometimes round and quite minute, then again they are large and obtusely
angular; the columella varies from very short and conical to longer and
more cylindric. _Diderma globuliferum_ of Fries S. M., _Physarum
albicans_ Peck. The specimens with the columella well nigh obsolete, may
be _Tilmadoche columbina_ Rost.
6. CYTIDIUM MELLEUM, B. & Br. Sporangium globose, stipitate or
subsessile; the wall a thin yellowish membrane, rugulose, covered by
large irregular scales of lime, honey-color to golden-yellow, breaking
up irregularly. Stipe short, sometimes very short or nearly obsolete,
snow-white, expanding at the base into a small white hypothallus,
tapering upward and entering the sporangium as a short obtusely conical
columella. Capillitium a loose net-work of delicate tubules with broad
vesicular expansions containing much lime; the nodules numerous, white
or sometimes yellow, large, irregular, lobed, and branched. Spores
globose, nearly even, pale violaceous, 7-9 mic. in diameter.
Growing on old leaves, sticks, herbaceous stems, etc.; not uncommon in
this region. Sporangium .4-.5 mm. in diameter, the stipe about the same
length or much shorter. _Didymium melleum_ B. & Br. _Didymium
chrysopeplum_ B. & C. also belongs here and not with _C. citrinum_.
Sec.2. REXIELLA. Sporangium ellipsoidal or pyriform, the columella
prolonged nearly to the apex of the sporangium.
7. CYTIDIUM PENETRALE, Rex. Sporangium ellipsoidal or pyriform,
stipitate; the wall a thin pellucid membrane, covered with small scales
of lime, yellow-gray to greenish-yellow, rupturing at maturity into two
to four segments. Stipe long, slender, translucent, pale red to dark red
in color, tapering upward, entering the sporangium and prolonged nearly
to the apex as a slender columella. Capillitium of very slender tubules,
radiating from numerous points of the columella, forming a delicate
net-work of very small meshes, scarcely expanded at the angles; the
nodules of lime small, not numerous, roundish or obtusely angled, white
or yellowish. Spores globose, very minutely warted, pale violaceous,
5.5-6.5 mic. in diameter.
Growing on old wood. A rare and singular species. Sporangium .5-.7 mm.
in height by .3-.5 mm. in diameter, the stipe two or three times the
height of the sporangium. There is an affinity between this species and
the _Physarella_. The obscure _Tilmadoche hians_ Rost., may be the same
as the present species.
EXPLANATION OF PLATE XIII.
Fig. 49.--Angioridium sinuosum, Bull. _a._ Plasmodiocarp x 5 _b._
Capillitium and spores x 500.
Fig. 50.--Cienkowskia reticulata, A. & S. _a._ Plasmodiocarp x 5. _b._
Piece of plasmodiocarp x 90. _c._ Capillitium and spores x 500.
Fig. 51. Leocarpus fragilis, Dicks, _a._ Sporangia x 5. _b._ Capillitium
and spores x 500.
Fig. 52.--Leocarpus caespitosus, Schw. _a._ Sporangia x 5. _b._
Capillitium and spores x 500.
Fig. 53.--Physarella oblonga, B. & C. _a._ Sporangia x 5. _b._ Sporangia
x 90. _c._ Capillitium and spores x 500.
Fig 54--Cytidium penetrale, Rex. _a._ Sporangia x 5 _b._ Sporangia and
columella x 90. _c._ Capillitium and spores x 500.
Fig. 55.--Cytidium globuliferum, Bull. _a._ Sporangia x 5. _b._
Sporangia x 90. _c_. Columella x 90 _d._ Capillitium and spores x 500.
[Illustration: The Journal of the Cin. Soc. Natural History.
VOL. XIX. PLATE XIII.
MORGAN ON MYXOMYCETES]
VI. CRATERIUM, Trent. Sporangium obovoid to cylindric, stipitate; the
upper and usually greater part of the wall covered with granules of
lime, the basal portion naked and more persistent. Stipe short or
sometimes elongated, arising from a small circular hypothallus,
longitudinally plicate, confluent above and similarly colored with the
base of the sporangium. Capillitium of tubules, forming a loose network,
bearing numerous large angular and irregular nodules of lime, which are
often confluent along the axis of the sporangium into a
pseudo-columella. Spores globose, minutely warted, violaceous.
In this genus the sporangium is commonly obovoid, with a naked base
which is confluent with the stipe and similarly colored; after
dehiscence there is left behind the more persistent cyathiform portion
standing on the substratum.
Sec.1. EU-CRATERIUM. Sporangium at maturity dehiscent in a regular
circumscissile manner, the apex falling away as a lid, leaving behind
the more persistent cup-shaped portion.
1. CRATERIUM MINUTUM, Leers. Sporangium cyathiform, stipitate; the lid
slightly convex, discrete from the first, usually depressed below the
rim of the cup, falling away at maturity, and leaving a smooth, circular
margin to the lower cyathiform portion. The wall a thick, firm,
yellow-brown membrane, the outer surface of the cup entirely naked,
smooth and shining, varying greatly in color from alutaceous or
ochraceous to various shades of brown; the lid usually whitened by a
thin layer of granules of lime. Stipe short, erect or bent, and slightly
curved at the apex, varying in color from rusty yellow to reddish brown,
longitudinally plicate, arising from a small, circular hypothallus.
Capillitium of tubules forming a loose net-work, bearing large,
irregular, white nodules of lime, which are sometimes confluent in the
axis of the sporangium. Spores globose, very minutely warted,
violaceous, 8-10 mic. in diameter.
Growing on old wood, sticks, leaves, etc. Sporangium, together with the
stipe, .8-1.4 mm. in height and .3-.5 mm. in diameter, the stipe usually
shorter than the sporangium, sometimes equal to it in length, rarely
longer. The latest authorities include the three species _Craterium
vulgare_, _C. pyriforme_, and _C. minutum_ of Rostafinski's monograph
all in one species.
2. CRATERIUM CONCINNUM, Rex. Sporangium usually minute, broadly
funnel-shaped, stipitate; operculum always more or less convex, rarely
approaching a hemispherical shape, dehiscent in a regular circumscissile
manner. The wall a thick, brownish membrane, externally smooth and
variously colored, sometimes uniformly light or dark umber, sometimes
dark brown below and brownish white above; the operculum brownish white,
darkest in the center. Stipe short, dark brown, longitudinally ridged.
Capillitium of tubules forming a close-meshed net-work, bearing small
rounded or slightly angular nodules of lime, ochre-brown in color.
Spores globose, very minutely warted, brown, 9-10 mic. in diameter.
Growing usually upon chestnut-burs, and frequently associated with
_Lachnobulus globosus_. Sporangium .5-.8 mm. in height including the
stipe and .2-.5 mm. in diameter at the top, the stipe equaling the
sporangium in length. It is readily distinguished by its small nodules
in the capillitium, which are invariably of a dull, brownish-ochre
color.
3. CRATERIUM RUBESCENS, Rex. Sporangium subcylindric or elongated
cyathiform, stipitate; the apex convex, at maturity separating by an
irregular line in a circumscissile manner. The wall dark violet-red,
smooth, except at the upper portion, which is slightly roughened by an
external deposit of scattered lime-granules of a pale, lilac color.
Stipe short, violet-black, wrinkled longitudinally. Capillitium of
tubules forming a loose, irregular net-work, bearing large, violet-red
nodules of lime which are often confluent in the axis of the sporangium.
Spores globose, minutely warted, dark violaceous, 7-9 mic. in diameter.
Growing on old wood, leaves, etc. Sporangium .6-.8 mm. in height
including the stipe and .5-.6 mm. in diameter, the stipe one-half the
height of the sporangium. The species is distinguished by the color,
which exhibits some shade of red or violet-red in every part of its
structure.
4. CRATERIUM MINIMUM, B. & C. Sporangium cylindric or turbinate
cylindric, stipitate; the apex convex, separating in a regular
circumscissile manner by a lid. The wall a thick, yellow-brown
membrane, most of the outer surface covered with minute, white granules
of lime, the basal portion naked. Stipe very short, plicate, red-brown,
arising from a small hypothallus. Capillitium of tubules forming a loose
net-work bearing large, irregular, white nodules of lime, sometimes
confluent in the axis of the sporangium. Spores globose, very minutely
warted, violaceous, 7-9 mic. in diameter.
Growing on old leaves, herbaceous stems, etc. Sporangium together with
the stipe 1-1.5 mm. in height and .25-.35 mm. in thickness, the stipe
.2-.4 mm. in length. This is a common species everywhere in the United
States, and perfectly distinct from _Craterium convivale_. It is
_Craterium cylindricum_ of Massee's monograph, according to Lister.
Sec.2. CUPULARIA, Link. Sporangium irregularly dehiscent, breaking up and
gradually falling away from the apex downward.
_a. Stipe shorter than the sporangium._
5. CRATERIUM CONVIVALE, Batsch. Sporangium obovoid or oblong-obovoid,
stipitate; the wall hyaline, thin and fragile above, the lower portion a
thickened and brownish membrane, the surface, usually most of it,
covered with minute white granules of lime, the base naked and brown.
Stipe very short, erect, red-brown, plicate, arising from a small
hypothallus. Capillitium of tubules forming a dense net-work, bearing
numerous large irregular white nodules of lime, which are often
confluent in the axis of the sporangium. Spores globose, very minutely
warted, violaceous, 8-10 mic. in diameter.
Growing on old leaves, herbaceous stems, etc. Sporangium .6-1.0 mm. in
height including the stipe and .3-.5 mm. in diameter, the stipe much
shorter than the sporangium. The thin apex breaks up into pieces and
falls away, leaving sometimes a regular cyathiform portion, at other
times the margin is broken and irregular. This is _Craterium
leucocephalum_ of Rostafinski's monograph. The specimens of _Physarum
scyphoides_ C. & B. which I have seen appear to be a small form of this
species.
6. CRATERIUM AUREUM, Schum. Sporangium obovoid to oblong obovoid,
stipitate, the wall a thin and delicate membrane above, thicker and
firmer below, hyaline or yellowish, almost entirely covered by a dense
layer of granules of lime, varying from lemon-yellow to orange in color.
Stipe short, erect, yellow to orange, brownish toward the base,
longitudinally plicate, rising from a small hypothallus. Capillitium of
slender tubules, forming a dense net-work, bearing numerous rather small
irregular nodules of lime, yellow or sometimes white in color, and often
confluent along the axis of the sporangium. Spores globose, very
minutely warted, dark violaceous, 8-10 mic. in diameter.
Growing on old leaves, sticks, herbaceous stems, etc. Sporangium and
stipe .7-1.0 mm. in height and .3-.5 mm. in diameter, the stipe .2-.4
mm. long. The elongated form is the common one in this region.
_Craterium mutabile_ Fr.
_b. Stipe longer than the sporangium._
7. CRATERIUM NODULOSUM, C. & B. Sporangium globose or obovoid,
stipitate; the greater part of the wall a thin hyaline membrane, easily
breaking away, covered externally with large white scales and nodules of
lime; the basal portion naked, thickened, and more persistent, red-brown
and plicate. Stipe long, erect or inclined, plicate, red-brown, rising
from a small hypothallus. Capillitium of tubules forming a loose
net-work, containing a variable quantity of lime in the shape of long
irregular white nodules, sometimes confluent, with pointed lobes and
branchlets. Spores globose, very minutely warted, dark violaceous, 10-12
mic. in diameter.
Growing on old wood, bark, leaves, etc. Sporangium .5-.6 mm. in
diameter, the stipe two or three times as long. It is _Badhamia
nodulosa_ C. & B., _Journal of Mycology_, Vol. V, p. 186. Ravenel's
specimens are on _Acacia_ bark. Mr. Webber sent me elegant specimens
from Florida where, he says, it grows commonly on the leaves and bark of
the orange trees.
8. CRATERIUM MAYDIS, Morgan, n. sp. Sporangium globose or obovoid,
stipitate; the upper part of the wall a yellowish membrane, thin and
fragile, covered with large thick scales and nodules of lime,
amber-colored to golden-yellow; the basal portion thicker and more
persistent, naked and plicate, red-brown. Stipe red-brown, long,
slender, plicate, rising from a small hypothallus. Capillitium of thick
tubules, forming a net-work with wide expansions at the angles; the
nodules of lime large, numerous, yellow, angularly lobed and branched.
Spores globose, very minutely warted, pale violaceous, 9-10 mic. in
diameter.
Growing on old stalks of _Zea mays_. Sporangium with the stipe 1-1.5 mm.
in height and .4-.6 mm. in diameter, the stipe always longer than the
sporangium. I find it in abundance on old stalks of Indian corn, but
never on anything else.
VII. PHYSARUM, Pers. Sporangium globose, depressed globose or irregular,
stipitate or sessile; the wall a thin membrane, with an outer layer of
minute roundish granules of lime, irregularly dehiscent. Stipe present
or often wanting, never prolonged within the sporangium as a columella.
Capillitium of slender tubules, forming an intricate net-work, the
extremities attached on all sides to the wall of the sporangium; the
tubules more or less expanded at the angles of the net-work, and
containing at varying intervals nodules of lime. Spores globose,
violaceous.
_Physarum_ is the central genus of the _Physaraceae_ from which all the
others are detached by characters which for the most part are
unimportant.
Sec.1. LAPIDIUM. Lime in the Capillitium scanty; the nodules small,
roundish, ellipsoidal or fusiform.
_A. Sporangium stipitate._
_a. Sporangia regular._
1. PHYSARUM NUTANS, Pers. Sporangium orbicular, very much depressed, the
base concave or umbilicate, stipitate, cernuous; the wall a thin
pellucid membrane, thickly covered with minute white or yellow roundish
scales of lime, breaking up into irregular fragments, which often remain
attached to the capillitium. Stipe long, slender, tapering upward, bent
or curved at the apex, longitudinally rugulose, brown or blackish at the
base, becoming paler upward and cinereous or whitish at the apex.
Capillitium of very slender threads, rising from the base of the
sporangium, forming a net-work with much elongated meshes, scarcely
expanded at the angles; the nodules of lime white or yellow, ellipsoidal
or fusiform, often very small and few in number, sometimes rather large
and numerous. Spores globose, very minutely warted, violaceous, 8-10
mic. in diameter.
Growing on wood, bark, mosses, etc. A very common species. Sporangium
.4-.5 mm. in diameter, the stipe 1-2 mm. in length, the lime-nodules
commonly not thicker than the spores, but sometimes from once to twice
their diameter. Under this name I have included all the lenticular
species of Persoon's Synopsis, _Physarum nutans_, _P. luteum_, _P.
viride_ and _P. aureum_. There is no difference in these species, except
in the color of the granules of lime; the form of the sporangium and the
shape and color of the stipe are the same in all of them. No two
authorities agree in the presentation of this species.
2. PHYSARUM CUPRIPES, B. & R. Sporangium orbicular, much depressed, the
base umbilicate, stipitate, cernuous; the greater part of the wall thin
and delicate, with a scanty covering of yellow granules of lime,
becoming naked and then brassy and iridescent, after maturity soon
disappearing; the lower basal portion thicker and more persistent, with
a layer of small yellow scales of lime. Stipe long, flexuous, bent at
the apex, plicate, pale brown to yellow-brown, darker toward the base.
Capillitium of slender tubules, forming a dense persistent net-work,
more or less expanded at the angles; the lime-nodules small, numerous,
yellow, angular and fusiform, below often confluent. Spores globose,
very minutely warted, violaceous, 8-10 mic. in diameter.
Growing on old wood; rare. Sporangium .4-.5 mm. in diameter, the stipe
two or three times this length. The lime nodules are found both on the
sides and at the angles of the meshes, and are fusiform or angular
accordingly; the lime is scanty above, but in the lower part of the
capillitium the nodules sometimes run together into lobed and branched
forms. This is _Physarum berkeleyi_ of Rostafinski's monograph.
3. PHYSARUM OBRUSSEUM, B. &. C. Sporangium globose, the base usually
slightly flattened or umbilicate, stipitate and cernuous; the wall a
thin, violaceous membrane, covered by small, roundish, white or yellow
scales of lime, or sometimes naked, splitting irregularly from the apex
downward. Stipe long, slender, tapering upward, flexuous, bent or curved
at the apex, yellow, yellow-brown, or pale brown. Capillitium of very
slender tubules, forming a loose net-work, scarcely expanded at the
angles; the nodules of lime small, white or yellow, roundish or obtusely
angular, few to numerous, rarely wanting. Spores globose, very minutely
warted, violaceous, 8-10 mic. in diameter.
Growing on old wood, bark, mosses, etc Sporangium .2-.4 mm. in diameter,
the stipe 1-2 mm. in length, the lime nodules when abundant once to
twice the diameter of the spores, when scanty very small. This, as I
find it growing, is an extremely variable species; I think its various
forms and appearances cover such species as _Didymium obrusseum_ B. &
C.; _D. tenerrimum_ B. & C.; _Physarum tenerum_ Rex, etc., etc.
4. PHYSARUM NUCLEATUM, Rex. Sporangium globose, stipitate, erect or
slightly nodding; the wall a thin, pellucid membrane, thickly covered
with minute, white, roundish scales of lime, which are exceptionally
sparse or absent, rupturing irregularly. Stipe long, slender,
yellowish-white, longitudinally rugulose, tapering upward, expanded at
the base into a small hypothallus. Capillitium of very slender tubules,
forming a delicate net-work of small meshes, scarcely expanded at the
angles; nodules of lime small, not numerous, roundish, white, usually
concentrated into a large lump in the center of the sporangium. Spores
globose, very minutely warted, violaceous, 6-7 mic. in diameter.
Growing on old wood, bark, etc.; rare. Sporangium .4-.5 mm. in diameter,
the stipe two or three times as long, the lime-nodules about the size of
the spores. The species much resembles some of the forms of _P.
obrusseum_, but is to be distinguished by its central mass of lime and
the small spores.
5. PHYSARUM COMPACTUM, Wingate. Sporangium depressed-globose, the base
slightly umbilicate, stipitate, cernuous; the wall a thin, violaceous
membrane, rugulose and iridescent, studded with large and thick,
snow-white, roundish or elliptic scales of lime, at maturity splitting
from the apex downward into several segments. Stipe long, rather weak,
bent and flexuous, tapering upward, longitudinally rugulose, from
snow-white to whitish-ochre and smoky-white, usually brownish at the
base, and arising from a thin hypothallus. Capillitium a delicate
net-work of very slender threads, with no expansions at the angles; the
lime mostly concentrated in one large, snow-white nodule at the center,
a few very small, roundish nodules scattered through the net-work.
Spores globose, very minutely warted, violaceous, 7-9 mic. in diameter.
Growing on old wood, mosses, etc.; a common species. Sporangium .4-.5
mm. in diameter, the stipe two or three times this length. _Tilmadoche
compacta_ Wingate. It is doubtful if _Tilmadoche columbina_ Rost.
belongs to this species. According to Lister, _Lepidoderma stellatum_
Massee, is the same as this species, and if it be objected to the name
that there is already a _Physarum compactum_ Ehrenberg, it may have to
be called _Physarum stellatum_.
_b. Sporangium more or less irregular_.
6. PHYSARUM LEUCOPHAEUM, Fr. Sporangium globose or depressed-globose,
more or less irregular, the base never umbilicate, stipitate or
subsessile; the wall a thin violaceous membrane, rugulose and
iridescent, with a thin coat of small white scales and granules of lime,
or sometimes nearly naked. Stipe variable in length, sometimes very
short or quite obsolete, occasionally a few of them confluent, wrinkled,
and sulcate, brown below, paler or whitish above. Capillitium a dense
irregular net-work of slender tubules, more or less expanded at the
angles; the nodules of lime white, small, roundish, or angular, few and
scattered. Spores globose, very minutely warted, violaceous, 8-10 mic.
in diameter.
Growing on old wood, bark, leaves, etc. The sporangium .5-.7 mm. in
diameter, the stipe about the same length, or shorter, and sometimes
wanting. The lime on the wall and in the capillitium is never abundant
and sometimes extremely scanty. Rostafinski's presentation of this
species applies well to our specimens.
7. PHYSARUM CONNEXUM, Link. Sporangia subglobose, depressed, more or
less irregular, sometimes confluent, stipitate, or subsessile; the wall
a thin violaceous, or brownish membrane, rugulose, thickly covered with
small white roundish scales of lime, which sometimes accumulate so as to
make the surface rough and uneven. Stipe short, thick, rugulose, from
snow white to smoky or sooty, especially toward the base, sometimes with
a scanty calcareous hypothallus. Capillitium a loose net-work of
tubules, much expanded at the angles; the nodules of lime small, white,
rather numerous, ellipsoidal or fusiform, sometimes confluent and
elongated. Spores irregularly globose, minutely warted, dark violaceous,
9-11 mic. in diameter.
Growing on old wood and bark. Sporangium .6-1.0 mm. in diameter, the
stipe usually shorter than the diameter, sometimes very short; the
lime-nodules about the thickness of the spores. This is a larger and
rougher species than _P. leucophaeum_, the sporangium is more often
irregular and the spores darker colored. _P. confluens_ and _P.
connexum_ of Link.