_=Tilmadoche= Fries_
53. PHYSARUM GYROSUM (_Rost._) _Jahn._
1875. _Physarum gyrosum_ Rost., _Mon._, p. 111.
1902. _Physarum gyrosum_ Rost., Jahn, _Ber. Deutsch. Bot. Ges._, XX.,
p. 272, t. XIII.
1911. _Physarum gyrosum_ Rost., List., _Mycetozoa, 2nd ed._, p. 75.
Sporangia gyrose, variable in form, or plasmodiocarpous and irregular,
venulose, sessile upon a common, strongly developed hypothallus,
sometimes isolated and irregularly globose, dehiscing irregularly or by
longitudinal fissure, yellowish or greyish white; columella none;
capillitium delicate, the nodules elongate, variable in size; spores
pale violaceous, minutely spinulose, 7-10 mu.
This is a European species recently resuscitated by Dr. Jahn. It perhaps
might more correctly be recorded as _P. gyrosum_ Jahn, since Rostafinski
certainly attempted in his description to cover two apparently distinct
things. He seems to have had before him _Fuligo muscorum_ Schw. and "_P.
gyrosum_," but he thought them the same, and his description touches now
one, now the other. Since _F. muscorum_ Schw. has all along held its own
and received due recognition, it is interesting to note the recovery of
this gyrose form.
Judging by description and figures, it resembles a very large, sessile
phase of _P. polycephalum_. See further under that species.
Europe, Japan, Eastern United States (?).
54. PHYSARUM POLYCEPHALUM _Schw._
PLATE VIII., Figs. 2, 2 _a_, 2 _b_.
1822. _Physarum polycephalum_ Schw., _Syn. Fung. Car._, No. 382.
1829. _Didymium polycephalum_ (Schw.) Fries, _Syst. Myc._, III.,
p. 122.
1837. _Didymium polymorphum_ Mont., _Ann. Sci. Nat._, Ser. 2, 8,
p. 361.
1837. _Didymium gyrocephalum_ Mont., _op. cit._, p. 362.
1875. _Physarum polymorphum_ (Mont.) Rost., _Mon._, p. 107.
1875. _Tilmadoche gyrocephala_ (Mont.) Rost., _Mon._, p. 131.
1899. _Tilmadoche polycephala_ (Schw.) Macbr., _N. A. S._, p. 57.
1911. _Physarum polycephalum_ Schw., List., _Mycetozoa, 2nd ed._,
p. 58.
Sporangia spherical or irregular, impressed, gyrose-confluent,
helvelloid, umbilicate below; peridium thin, ashy, covered with
evanescent yellow squamules, fragile; stipe from an expanded
membranaceous base, long-subulate, yellow; spores smooth, violet, 9-11
mu.
A most singular species and well defined is this, occurring in masses of
decaying leaves or on rotten logs. The plasmodium at first colorless; as
it emerges for fructification, white, then yellow, spreading far over
all adjacent objects, not sparing the leaves and flowers of living
plants; at evening slime, spreading, streaming, changing; by morning
fruit, a thousand stalked sporangia with their strangely convoluted
sculpture. The evening winds again bear off the sooty spores, and naught
remains but twisted yellow stems crowned with a pencil of tufted silken
hairs. August.
Although Rostafinski's description of this species is accurate and marks
exactly a _Tilmadoche_ and is very different from his description of
_Physarum polymorphum_, nevertheless it is probable that both
descriptions have reference to the same thing. All specimens on which
both species were based were American; _P. polymorphum_, North American.
But the only North American form to which reference can be made is that
by Schweinitz called _P. polycephalum_ and, fortunately, sufficiently
described. Furthermore, Rostafinski, under _T. gyrocephala_, himself
affirms the probable identity of Montagne's _Didymium gyrocephalum_ with
the Schweinitzian species, and uses Montagne's specific name
provisionally. For these reasons it seems proper to write the species as
above.
Widely distributed and common, from Maine and Canada to Nebraska, and
Washington and south to Nicaragua.
This species is so common that its plasmodium and fructification may be
easily observed. Professor Morton E. Peck, who has been for years a
close observer of the vegetative phases of our Iowa species, says of _P.
polycephalum_: "In one instance I observed a plasmodium for twelve
successive days on the surface of a decaying stump. During this period
it crept all around the stump and from top to bottom several times. At
one time the color was bright yellow; at another, greenish yellow; and
once, shortly before fruiting, it became clear bright green. A heavy
rain fell upon the plasmodium but it appeared to sustain little injury
and ultimately developed normal sporangia."
55. PHYSARUM NUTANS _Pers._
1791. _Sphaerocarpus albus_ Bull., _Champ._, p. 137, t. 407, III.,
and t. 470, I, A-L.
1791. _Stemonitis alba_ (Bull.), Gmel., _Syst. Nat._, p. 1469 (?).
1795. _Physarum nutans_ Pers., _Ust. Ann. Bot._, XV., p. 6.
1803. _Trichia cernua Schum., Enum. Pl, Saell._, II., p. 241.
1829. _Physarum cernuum_ (Schum.) in part, Fr., _Syst. Myc._, III.,
pp. 130, 147.
1848. _Tilmadoche cernua_ (Schum.) Fr., _Summ. Veg. Sc._, p. 454.
1873. _Tilmadoche nutans_ (Pers.) Rost., _Versuch_, p. 10.
1899. _Tilmadoche alba_ (Bull.) Macbr., _N. A. S._, p. 58.
1911. _Physarum nutans_ Pers., List., _Mycet., 2nd ed._, p. 67,
in part.
Sporangia gregarious, depressed-spherical, stipitate, umbilicate, gray
or white, thin-walled, nodding; stipe long, tapering upward, brown or
black below, ashen white above, lightly striate, graceful; capillitium
abundant, threads delicate, intricately combined in loose persistent
network with occasional minute, rounded, or elongate calcareous nodules;
spores minutely roughened, globose, about 10 mu.
The nodding, lenticular, umbilicate sporangium, barely attached to the
apiculate stipe, is sufficient to distinguish this elegant little
species, recognized and quite aptly characterized by mycologists for
more than one hundred years. As _Sphaerocarpus albus_ Bulliard first
prescribed the limits by which the species is at present bounded. The
description by Fries (_Syst. Myc.,_, III., 128) is especially graphic;
"Peridium very thin, in form quite constantly lenticular, umbilicate at
base, at first smooth then uneven, generally laciniate-dehiscent, the
segments persistent at least at base."
The stipe is usually white above, fuscous below, at the apex almost
evanescent; hence the cernuous sporangia. The same character is less
strikingly manifest in the species next following.
The plasmodium is bright yellow, sometimes greenish. Brought in from the
field and maturing under a bell-jar, the color changes to a watery white
just before the sporangia rise in fruit. _P. album_ Fuckel, _Rhen. Fl._,
No. 1469, 1865, is believed to be _P. cinereum_ (Batsch) Pers.
Persoon changed Bulliard's specific name in this case to furnish one
himself, more descriptive as he thought and distinctive. His success in
this attempt must be esteemed but partial since all the related forms,
immediately listed, _nod_ as well. Bulliard's name as applied by Persoon
is therefore to be preferred. But the transfer from _Tilmadoche_ to
_Physarum_ loses for us one step in the ladder of priority. _P. album_
(Bull.) may not enter here, since Fries has given us one species under
that title. So Persoon comes next on the list, all the world now nodding
approbation, let us hope!
Under the name _Physarum gracilentum_, Fries cites an extremely delicate
form of this species. The sporangia are of the most minute, about .2-.3
mm. in diameter, globose, slightly umbilicate below, the stipe usually
white at top, but sometimes black throughout. This graceful form occurs
rarely in undisturbed woods.
Widely distributed in the eastern United States, apparently rare in the
west. Reported from various parts of the world; Europe, Japan,
Australia, etc.
56. PHYSARUM VIRIDE (_Bull._) _Pers._
PLATE VIII, Figs. 8, 8 _a_, 8 _b_.
1791. _Sphaerocarpus viridis_ Bull., _Champ._, t. 407, Fig. I.
1791. _Sphaerocarpus luteus_ Bull., _Champ._, t. 407, Fig. II.
1791. _Sphaerocarpus aurantius_ Bull., _Champ._, t. 484, Fig. II.
1791. _Stemonitis viridis_ (Bull.) Gmel., _Sys. Nat._, p. 1469.
1794. _Physarum aureum_ Pers., Roemer, _Neu. Mag. f. die Bot._, I.,
p. 88.
1795. _Physarum viride_ Pers., Usteri, _Ann. Bot._, XV., p. 6.
1801. _Physarum aurantium_ Pers., _Syn. Meth._, p. 173.
1829. _Physarum nutans_ var. Fries, _Syst. Myc._, III., pp. 128-129.
1875. _Tilmadoche mutabilis_ Rost., _Mon._, p. 129.
1880. _Tilmadoche viridis_ (Bull.) Sacc., _Michelia_, II., p. 263.
1894. _Physarum viride_ Pers., List., _Mycetozoa_, p. 50.
1899. _Tilmadoche viridis_ (Bull.) Sacc., Macbr., _N. A. S._, p. 59.
1911. _Physarum viride_ Pers., List., _Mycetozoa_, 2nd ed.
Sporangia globose, flattened or lenticular, beneath plane or concave,
variously colored, yellow, greenish yellow, rusty orange, stipitate,
nodding; the peridium splitting irregularly or reticulately; stipe
variable in length and color, through various shades of red and yellow,
subulate; capillitium strongly developed, concolorous with sporangium,
the tubes with colorless or yellow calcareous thickenings; spores
smooth, fuscous or violet-black, 8 mu.
A very handsome and rather common little species; like the preceding,
but generally greenish-yellow in color, and occasionally brilliantly
orange without a suggestion of green. Indeed, the color is so variable
that some authors have been disposed to discard the species entirely,
inasmuch as the chief specific character is color. The plasmodium is
pale yellow, in rotten logs, stumps, etc. In the paler yellow or
greenish forms the stipe is more commonly black.
This is _Physarum luteum_ (Bull.) Fries, and likewise also includes the
three varieties, _viride_, _aureum_, _coccineum_, listed by the same
author under _P. nutans_, while he at the same time remarks that they
might with equal propriety be elsewhere referred. Rostafinski considers
that all the colored forms agree in capillitium sufficiently to be
associated under one name and are in the same way unlike _T.
nutans_.[29] Rostafinski thinks to avoid confusion by suggesting a more
fitting specific name, _T. mutabilis_, but there seems no good reason
for not adopting the earliest identifiable specific appellation, which
in this case appears to be _viride_. The yellow phase is common in Iowa,
resembles in size, color, stipe, _P. galbeum_ Wingate, but is instantly
distinguishable by the capillitium. _N. A. F._, 1213.
Widely distributed specimens are before us;--from New England, New York,
Pennsylvania, Maryland, Ohio, Nebraska, Iowa, California, Oregon,
Canada, Nicaragua, Samoa, Alaska, India, etc.
=EXTRA-LIMITAL=[30]
PHYSARUM MUTABILE (_Rost._) _List._
1875. _Crateriachea mutabilis_ Rost., _Mon._, p. 125.
1892. _Crateriachea mutabilis_ Rost., Mass., _Mon._, p. 344.
1894. _Physarum cinereum_ List., _Mycetozoa_, p. 55, in part.
1895. _Physarum crateriachea_ List., _Jour. Bot._, XXXIII., p. 323.
1910. _Physarum crateriachea_ List., Petch, _Mycetozoa Ceylon_,
p. 336.
1911. _Physarum mutabile_ List., _Mycetozoa, 2nd ed._, p. 53.
Sporangia cylindrical ovoid or sub-globose white, plasmodiocarpous,
sessile or stipitate, stipes when present yellow, with or without lime,
often connected by a hypothallus; peridium thin, squamulose;
capillitium persistent, intricate, the nodules white, more or less
confluent at the center to form a real or a pseudo-columella; spores
brownish-purple, spinulose, 7-8 mu.
Reported from Europe, Africa, Ceylon.
PHYSARUM ROSEUM _Berk. & Br._
1873. _Physarum roseum_ Berk. & Br., _Jour. Linn. Soc._, XIV., p. 84.
Plasmodium rose-red; sporangia gregarious, stipitate, globose, rose-red;
the stipe erect, brown, rugulose, translucent; capillitium lax,
delicate, lilac, the nodules few, large, purple-red, branching; spores
reddish-lilac or brown, minutely spinulose, 7-10 mu.
Reported from Ceylon, Java, Borneo, Japan.
PHYSARUM DICTYOSPERMUM _List._
1905. _Physarum dictyospermum_ List., _Jour. Bot._, Vol. XLIII.,
p. 112.
"It is distinguished from the other known species of _Physarum_ by the
strongly reticulated spores. Its nearest ally is perhaps _P.
psittacinum_ which it resembles in having orange-red lime-knots and in
the sporangium-wall being studded with orange crystalline disks."
_Lister._
Reported collected once only; New Zealand.
PHYSARUM STRAMINIPES _List._
1898. _Physarum straminipes_ List., _Jour. Bot._, Vol. XXXVI., p. 163.
Plasmodium white; sporangia greyish-white, obovoid or wedge-shaped, .7
mm. in diameter, clustered or scattered, stipitate or sessile, when
stipitate stalks long, weak; peridium membranous, pale purple;
capillitium a persistent rigid net, the nodules white, rounded,
sometimes aggregate as a pseudo-columella; spores purple-brown, 10-11 mu,
warted, the papillae in definite patches.
Related to _P. compressum_.
Reported from England; Germany.
PHYSARUM CRATERIFORME _Petch._
_Physarum crateriforme_ Petch, _Ann. Perad._, IV., p. 304.
_Physarum crateriforme_ Petch, List., _Mycetozoa, 2nd ed._, p. 69,
Pl. 76.
Sporangia gregarious, globose, clavate or crateriform, sessile or
stipitate, white; stalk when present opaque conical, black below, white
above, in crateriform sporangia entering and developed as a columella;
capillitium various, strongly calcareous, the nodules either grouped in
a pseudo-columella, or in globose sporangia, rod-like, ascending; spores
closely spinulose, 11-15 mu.
Reported from Ceylon, Japan, West Indies; Lisbon.
PHYSARUM GULIELMAE _Penzig._
1898. _Physarum gulielmae_ Penzig., _Myx. Beut._, p. 34.
1909. _Physarum gulielmae_ Penzig., Torrend, _Fl. des Myx._, p. 208.
1911. _Physarum gulielmae_ Penzig., List., _Mycetozoa, 2nd ed._,
p. 76.
Plasmodium yellow; sporangia sub-globose, sessile, brownish-orange or
chestnut brown, rugulose, clustered or heaped, often with a yellow
membranous hypothallus; peridium membranous with clustered deposits of
yellowish-brown lime granules; capillitium abundant, the nodes angular,
branching, white; spores purplish brown, spinulose, 10-12 mu.
Reported from Java, Sweden, Switzerland.
PHYSARUM ECHINOSPORUM _List._
1899. _Physarum echinosporum_ List., _Jour. Bot._, XXXVII., p. 147.
This species is distinguished from the preceding chiefly in episporic
characters. "Spores purple, 8 mu, marked by strong ridges and spines," 8
mu.
Reported from Antigua.
PHYSARUM AENEUM (_List._) _R. E. Fries._
1898. _Physarum murinum_ var. _aeneum_ Lister, _Jour. Bot._, XXXVI.,
p. 117.
1903. _Physarum aeneum_ Lister, R. E. Fries, _Arkiv. Bot._, I., p. 62.
Sporangia sessile, sub-globose or plasmodiocarpous, pinkish-brown or
bronze, glossy; peridium double, the outer somewhat cartilaginous,
brittle, falling back from the shining, membranous inner wall;
capillitium dense, the nodules not large, brown, sometimes aggregated to
form a pseudo-columella; spores pale brownish-violet, nearly smooth, 6-8
mu.
Reported from West Indies, Bolivia.
=Related Genus=
TRICHAMPHORA _Junghuhn_, p. 12.
1838. _Trichamphora_, Junghuhn, _Fl. Crypt. Javanica_.
Sporangia discoidal, above concave, saucer-shaped, stipitate; the
capillitium variable, anon physaroid, badhamioid, or even as in
_Didymium_.
This genus is set up for the accommodation thus far of the single
species following. It differs from _Physarella_ in the apparently
constant discoidal shape, absence of trabecules, etc.
TRICHAMPHORA PEZIZOIDEA _Jungh._, _op. cit._
1838. _Trichamphora pezizoidea_ Jungh., _op. cit._
1854. _Didymium zeylanicum_ Berk. & Br., _Hook. Jour. Bot._, VI.,
p. 230.
1869. _Physarum macrocarpum_ Fuckel, _Symb. Myc._, p. 343.
1875. _Chondrioderma pezizoidea_ Rost., _Mon._, p. 424, tab. VIII.,
Fig. 122.
1876. _Badhamia fuckeliana_ Rost., _Mon._, _App._, p. 2.
1894. _Trichamphora pezizoidea_ Jungh., List., _Mycetozoa_, p. 89.
1911. _Trichamphora pezizoidea_ Jungh., List., _Mycetozoa, 2nd ed._,
p. 90.
Sporangia discoidal or saucer-shaped, gregarious, stipitate, erect or
nodding, grayish-white, the peridium thin, breaking irregularly and
persistent; stipe subulate, striate, reddish brown, transparent;
capillitium variable as above stated; spores pale violet-brown,
spinulose or nearly smooth, about 9 mu.
In _Mycetozoa, 2nd ed._, the spores are described as "dark or pale
purplish brown, spinose, spinulose or nearly smooth, 9-17 mu in
diameter." This would seem too great a variation even in this protean
species. The only specimens in our herbarium are from the Congo valley.
The spores are pale and nearly smooth, as in _Tilmadoche alba_, and 9 mu.
Spores 17 mu suggest immaturity; penultimate cell-division.
The synonymy above cited shows how this species has impressed careful
students. Doubtless in every case the reference is correct, judging from
the specimen each author had before him, although it is hard to see how
_Chondrioderma_ might have been suggested.
The species is evidently tropical, though reported from Europe.
=4. Craterium= _Trentepohl_
1797. _Craterium_ Trentepohl, Roth, _Catal._, I., p. 224.
Sporangia more or less distinctly cyathiform, stipitate, the peridium
generally plainly of two layers or even of three, opening at the top by
circumscission more or less definite, or by a distinct lid, the upper
part calcareous often to a marked degree, the lower, cartilaginous, long
persistent as a vasiform cup containing the capillitium and spores, the
calcareous nodes aggregating more or less to form a pseudo-columella.
This genus is distinguished from _Physarum_ and _Badhamia_ chiefly by
the form of the sporangia and the method of dehiscence. The capillitium
is in some specimens particularly, of the _Physarum_ type; in others,
like that of _Badhamia_. There are accordingly species that receive at
the hands of different authors diverse generic reference as one feature
or another in the structure is emphasized in the different cases. It is
granted that it is hard to draw the line sometimes between forms in
which the dehiscence is irregularly circumscissile and those in which
the wall breaks without any regularity whatever, since, in all, the
breaking up of the peridium usually begins at the top. Species here
included will, however, offer little ambiguity.
=Key to the Species of Craterium=
A. Dehiscence circumscissile or by the breaking up of the upper wall
of the sporangium.
_a._ Sporangia violet or purple 1. _C. paraguayense_
_b._ Sporangia yellow 2. _C. aureum_
_c._ Sporangia white-capped.
1. Sporangia obovoid or globoid 3. _C. leucocephalum_
2. Sporangia cylindric, elongate 4. _C. cylindricum_
B. Dehiscence by a distinct lid.
_a._ Capillitium pale brown 5. _C. concinnum_
_b._ Capillitium white 6. _C. minutum_
1. CRATERIUM PARAGUAYENSE (_Speg._) _List._
1883. _Didymium paraguayense_ Speg., _Fung. Guar. Pug._, 1, p. 141.
1893. _Craterium rubescens_ Rex, _Proc. Philad. Acad. Nat. Sci._,
p. 370.
1894. _Craterium rubescens_ Rex, List., _Mycetozoa_, p. 71.
1899. _Craterium rubescens_ Rex, Macbr., _N. A. S._, p. 75.
1904. _Iocraterium paraguayense_ (Speg.) Jahn, _Hedwigia_, XLII.,
p. 302.
1911. _Craterium paraguayense_ List., _Mycetozoa, 2nd ed._, p. 95.
Sporangia gregarious, cylindrical or elongate cyathiform, stipitate,
dark violet-red, the apex slightly roughened by pale calcareous
granules, the peridium longitudinally wrinkled below; dehiscence,
irregularly circumscissile; stipe darker, one-half the height of the
sporangium, longitudinally wrinkled; capillitium dense, abundantly
calcareous; spores violet-brown, minutely roughened, 7-8 mu.
In form resembling the following species, but instantly distinguished by
the color, which is red throughout, tinged with purple or violet. The
capillitium is badhamioid, as noted by Dr. Rex. Very distinct from _P.
newtoni_ in color, form, habit, epispore, etc.
2. CRATERIUM AUREUM (_Schum._) _Rost._
1803. _Trichia aurea_ Schum., _Enum. Pl. Saell._, II., p. 207.
1829. _Craterium mutabile_ Fries, _Syst. Myc._, III., p. 154.
1875. _Craterium aureum_ (Schum.) Rost., _Mon._, p. 125.
Sporangia gregarious, globose or obovoid, stipitate, yellow, erect, the
peridial wall thin, especially at the summit, where at maturity it
breaks up somewhat reticulately, leaving the persistent lower portion
with an uneven margin above which projects the pale yellow capillitium;
stipe short, orange, or brownish-red, arising from a small hypothallus;
capillitium dense, yellow, the nodules not large, irregular, tending to
form a pseudo-columella in the centre of the cup; spores minutely
warted, violaceous-brown, 8-10 mu.
Fries regards this, which he names _C. mutabile_, the most distinctly
marked species of the genus; chiefly, as it appears, on account of the
bright yellow color. This, however, varies. Some specimens before us are
gray, showing only a trace of yellow below. In some European specimens a
reddish tinge prevails. The form of the sporangium also varies. In
typical specimens, unopened, the shape is almost pyriform; opened, we
have a cylindric, oftenest lemon-yellow vase, mounted on a short striate
stalk. But again, from the same plasmodium, we may have globose
sporangia, opening so as to leave only a shallow, salver-shaped base. In
this case the stipe is also longer. The plasmodium is said to be "clear
lemon yellow."--_Massee._
There seems little doubt that Schumacher had in mind the present
species in his _Trichia aurea_. Rostafinski shows that Fries's synonym,
_C. mutabile_, is founded on a mistake. The earlier specific name is
therefore on Rostafinski's authority adopted.
Not common. Pennsylvania, New Jersey, North Carolina, Ohio, Iowa.
3. CRATERIUM LEUCOCEPHALUM (_Pers._) _Ditmar_.
PLATE VIII., Fig. 5.
1791. _Stemonitis leucocephala_ Gmelin, _Syst. Nat._, II., p. 1467.
1801. _Arcyria_ (?) _leucocephala_ Persoon, _Syn. Fung._, p. 183.
1801. _Craterium_ (?) _leucocephalum_, Persoon, _Syn. Fung._, p. 184.
1813. _Craterium leucocephalum_ (Pers.) Ditmar, Sturm, _Deutsch.
Flora, Pilze_, p. 21, Pl. 11.
1889. _Physarum scyphoides_ Cke. & Balf., _Jour. Myc._, V., p. 186.
1896. _Craterium convivale_ (Batsch) Morg., _Jour. Cin. Soc._, p. 86.
Sporangia gregarious, short-cylindric or ovate, pure white above, brown
or reddish-brown below, stipitate, dehiscence irregularly
circumscissile, the persistent portion of the peridium beaker-shaped;
stipe short, stout, expanded above into the base of the peridium with
which it is concolorous; hypothallus scant; capillitium white or
sometimes, toward the centre, brownish, the calcareous nodules large,
conspicuous, and persistent; spore-mass black, spores violaceous-brown,
minutely spinulose, 8-9 mu.
Distinguished by its white cap from all except the next, from which the
markedly different form serves as the diagnostic feature. In some
gatherings, curious patches of yellow mark the otherwise snow white cap
and sides; these are mere stains, or sometimes definite, crystalline,
flake-like bodies, standing out in plain relief on the sporangial wall,
or lurking in the larger nodules which are massed along the axis of the
cup to form the pseudo-columella here strongly developed. Mr. Lister
calls attention to these yellow flakes, and regards them as diagnostic.
European specimens show the capillitium yellow, sometimes throughout!
The nomenclature question is here somewhat difficult. Fries heads his
list of synonyms with _Peziza convivalis_ Batsch. Batsch simply
described Micheli's figure! Now there is nothing in Micheli's figure
(Pl. 86, Fig. 14) to enable one to say with certainty which craterium
Micheli had in mind, if craterium at all. Nor does Batsch help the
matter when he offers the description following: "Stipitata; acute
conica, patens; stipite subdistincto, lineari, brevi, valido. _Albicans.
In foliis hederae putridis._" (_Elenchus Fungorum_, Batsch, 1783, p.
121.) There is nothing definitive here but the one word "albicans"
quoted from Micheli. But this term is applicable the rather to _C.
minutum_, the cups of which whiten with weathering. It may be, as
insisted by Fries (_Syst. Myc._, III., p. 149), that Micheli drew
crateriums; but if so, we cannot determine which species.
The specific name here adopted was applied by Persoon probably to this
form; but Persoon likewise failed to distinguish the present species
from _C. minutum_ (see _Syn. Fung._, pp. 183, 184), and Fries, _op.
cit._, p. 153. Ditmar, _l. c._, leaves no doubt as to what he figures
and describes, and accordingly the name he first correctly uses is here
adopted.
Not common. New England, Pennsylvania, Ohio, North Carolina, Iowa,
Colorado, Washington, California; reported from Europe.
4. CRATERIUM CYLINDRICUM _Massee_.
PLATE XVI., Fig. 2.
1873. _Craterium minimum_ Berk. & C., _Grev._, II., p. 67.
1892. _Craterium cylindricum_ Massee, _Mon._, p. 268.
1894. _Craterium leucocephalum_ Ditm., List., _Myc._, p. 72, in part.
1899. _Craterium minimum_ Berk. & C., Macbr., _N. A. S._, p. 77.
1911. _Craterium leucocephalum_ var. _cylindricum_ List., _Mycetozoa,
2nd ed._, p. 97.
Sporangia closely gregarious, very small, .5 mu or less, slender,
cylindric, almost entirely white, stipitate, the peridium delicate,
transparent although calcareous nearly to the base, opening by a
dehiscence regularly circumscissile; stipe short, about one-third the
total height, clear orange-brown, somewhat furrowed, rising from an
indistinct hypothallus; capillitium very lax, physaroid, the calcareous
nodules large, rounded, pure white, aggregated at the centre of the cup;
spore-mass black, spores minutely roughened, violaceous-brown, 8-9 mu.
This is the common form in the United States. Massee describes it as _C.
cylindricum_ Mass., and it seems not to occur in Europe. Lister has put
it in with _C. leucocephalum_, from which its more delicate structure
and elegant cylindrical shape certainly distinguish it. The dehiscence
is even more regular than in the preceding species and approaches that
of _C. minutum_ Leers., with bleached forms of which it must not be
confused. _N. A. F._, 1400.
_C. minimum_ Berk. & C. has here priority. Massee regards this name as
indicating a distinct species. We have been unable to determine what the
authors really had before them, and adopt accordingly the first
available combination.
New England to Iowa and south; reported also from the orient.
5. CRATERIUM CONCINNUM _Rex._
1893. _Craterium concinnum_ Rex, _Proc. Phila. Acad._, p. 370.
Sporangia scattered, usually minute, broadly funnel-shaped, stipitate.
The peridium simple, variously colored by innate lime granules, opening
by a regular cap or operculum, brownish white, darkest in the centre,
always more or less convex; stipe equalling the cup in height, dark
brown, longitudinally ridged; the capillitium a close-meshed network,
with small rounded or slightly angular masses of ochre-brown
lime-granules, larger toward the centre; spores pale brown, minutely
warted, 9-10 mu.
This species differs from the following, to which it seems most nearly
allied, in form, color, as in the capillitium, and color of the spores.
In habitat, however, it seems no less distinct, being found always (?)
on the spines of decaying chestnut-burs lying on the ground, and in
company with that other peculiar species _Lachnobolus globosus_.
The range is probably that of the chestnut, _Castanea dentata_
Borkhausen, east of the Mississippi River.
6. CRATERIUM MINUTUM (_Leers_) _Fr._
PLATE XV., Fig. 5.
1775. _Peziza minuta_ Leers, _Fl. Herborn_, p. 277.
1797. _Craterium pedunculatum_ Trent., Roth., _Catal. Bot._, I.,
p. 224.
1813. _Craterium vulgare_ Ditmar, Sturm, _Deutsch. Fl. Pilze_, p. 17.
1829. _Craterium pedunculatum_ Trent., Fr., _Syst. Myc._, III.,
p. 150.
1829. _Craterium minutum_ Leers, Fr., _Syst. Myc._, III., p. 151.
1893. _Craterium pedunculatum_ Trent., Macbr., _Bull. Lab. Nat. Hist.
Iowa_, II, p. 385.
1894. _Craterium pedunculatum_ Trent., Lister, _Mycetozoa_, p. 70.
1899. _Craterium minutum_ (Leers) Fr., Macbr., _N. A. S._, p. 78.
1911. _Craterium minutum_ Fr., List., _Mycetozoa, 2nd ed._, p. 94.
Sporangia scattered, gregarious, cyathiform or turbinate, grayish brown,
stipitate, the peridial wall rather thick, double, opening by a distinct
lid which lies usually below the slightly thickened and everted margin
of the cup; stipe paler, translucent, about equalling in height the
peridial cup, longitudinally wrinkled, with hypothallus scant or none;
capillitium physaroid, the calcareous nodules large, white, and
generally aggregated at the centre of the cup; spore-mass black, spores
by transmitted light violaceous, minutely warted, 8-10 mu.
This is the most highly differentiated of the whole series. The cup is
shapely and well defined, while the lid is not only distinct, but is a
thin, delicate membrane of slightly different structure when compared
with the peridial wall. It is in all the specimens before us much
depressed below the mouth of the sporangium, and the whole structure in
our specimens corresponds with Fries' description of _C. pedunculatum_
Trent., while specimens received from Europe correspond to Fries'
account of _C. minutum_ Leers. Nevertheless we are assured that the two
forms are in Europe developed from the same plasmodium, and therefore
adopt the earlier specific name as above. _N. A. F._, 2500. This is
probably _Fungoides convivalis_ of Batsch and Micheli.
In this species yellow sporangia are sometimes seen. Miss Currie reports
from Toronto such variation and in Europe the case seems not unusual.
In fact, there is a yellow tinge about the sporangia of every species
listed here, except the first. With the same exception, the plasmodium
in every case is yellow.
Common throughout the eastern United States, west to Iowa, Colorado, and
south to Louisiana; cosmopolitan.
=5. Physarella= _Peck._
1882. _Physarella_ Peck, _Bull. Torr. Bot. Club_, IX., p. 61.
Sporangium pervious to the base, the interior walls forming a persistent
spurious columella; capillitium composed of filaments with here and
there minute knot-like thickenings, straight tubes containing
lime-granules extending from the exterior to the interior walls of the
sporangium, persistently attached to the former.[31]
Such is Dr. Peck's original description of this most peculiar genus. The
form of the sporangium in the only species is very variable, but in
typical cases is vasiform, the peridial wall at the apex introverted.
The capillitium is like that of _Tilmadoche_, except for the presence of
the "straight tubes" emphasized in the original description. These are
very remarkable and at once diagnostic. They take origin in the
sporangial wall and pass across to the "columella"; but at the
dehiscence of the sporangium, in typical cases, they remain attached at
the points of origin, projecting as stout spine-like processes.
PHYSARELLA OBLONGA (_Berk. & C._) _Morg._
PLATE VIII., Figs. 4, 4 _a_, 4 _b_, 4 _c_; PLATE XVI., Figs. 1, 1 _a_, 1
_b_, and 6.
1873. _Trichamphora oblonga_ Berk. & C., _Grev._, II., p. 66.
1876. _Tilmadoche oblonga_ (Berk. & C.) Rost., _Mon. App._, p. 13.
1876. _Tilmadoche hians_ Rost., _Mon. App._, p 14.
1882. _Physarella mirabilis_ Peck, _Bull. Torr. Bot. Club_, IX.,
p. 61.
1893. _Physarella oblonga_ (Berk. & C.) Morg., _Jour. Cin. Soc._,
p. 79.
1894. _Physarella mirabilis_ Peck, List., _Mycet._, p. 68.
1899. _Physarella oblonga_ (Berk. & C.) Morg., Macbr., _N. A. S._,
p. 71.
1911. _Physarella oblonga_ Morg., List., _Mycet., 2nd ed._, p. 91.
Sporangia scattered or gregarious, typically cup-shaped or
sub-infundibuliform, stipitate, erect or cernuous, but varying through
low salver-shaped cups, to irregular applanate and sessile masses, the
peridium thin but firm, tawny, roughened by numerous yellowish
calcareous scales, at length ruptured above and often reflexed in the
form of petal-like segments from which project upwards the spiniform
trabecules of the capillitium; stipe when present long, terete, red,
arising from a scant hypothallus and extended within the sporangium to
meet the tubular "columella"; capillitium of delicate violaceous threads
seldom branched or united, radiating from the columella with few
calcareous nodular expansions, but supported by stout yellow calcareous
trabecules, running parallel to the capillitial threads, long adherent
to the sporangial wall; spores smooth, globose violet-brown, 7-8 mu.
Not uncommon in wet places. New York, Ohio, Iowa, South Dakota,
Louisiana, Nicaragua; reported also from Ceylon, Java, etc.
Not the least remarkable feature of this remarkable species is the
variation in the form of the fruit or sporangia. We have specimens from
Louisiana (Rev. Langlois) which show no trace of columella, the whole
structure involute and plicate, short stipitate, recalling the extremest
complexity of such a species as _P. polycephalum_. _Vid._ Pl. XVI., Fig.
6. Moreover, in these specimens the calcareous deposits are white and
not yellow, giving the entire fructification a grayish aspect. Yet there
is no doubt we have here simply an exaggerated abnormality of the
species; the spores are identical in size, color, and surface.
Plasmodium bright yellow. Dr. Peck gave to his forms the name
_Physarella mirabilis_; but specimens sent by Michener of Pennsylvania,
and by Berkeley and Curtis described as _Trichamphora oblonga_ (_Grev._,
II., p. 66), are the same thing. _N. A. F._, 1212.
_Physarella lusitanica_ Torrend is a globose form depressed above or
betimes discoidal, occurring on Eucalyptus trees in Portugal. _P.
oblonga_ is so variable in form that it sometimes suggests a different
genus. Forms of it have been mistaken for _Fuligo gyrosa_ R., etc.
Professor Torrend would include here _Physarum javanicum_ (Rac.), i. e.
_Tilmadoche javanica_ as Raciborski saw it! We may not too often reflect
that genera are purely artificial things set up for our convenience; but
surely _Physarella_ as a natural genus is distinct enough to all.
=6. Cienkowskia= _Rost._
1873. _Cienkowskia_ Rost., _Versuch_, p. 9.
Fructification plasmodiocarpous, irregularly dehiscent, the wall a thin
cartilaginous membrane destitute of lime, except the capillitial
attachments within; capillitium scanty but rigid, and characterized
everywhere by peculiar hook-like branchlets, free and sharp-pointed, the
spores as in _Physarum_, etc.
The genus contains, so far, but a single species:--
CIENKOWSKIA RETICULATA (_Alb. & Schw._) _Rost._
PLATE XIV., Figs. 2, 2 _a_, 2 _b_.
1805. _Physarum reticulatum_ Alb. & Schw., _Cons. Fung._, p. 90.
1829. _Diderma reticulatum_ Fr., _Syst. Myc._, III., p. 112.
1873. _Cienkowskia reticulata_ (Alb. & Schw.) Rost., _Versuch_, p. 9.
Plasmodiocarp an elongated, irregularly limited, close-meshed net,
closely applied to the substratum, the wall thin, transversely rugulose,
and roughened, dull orange-yellow, splashed here and there with scarlet,
anon entirely red, within marked by transverse calcareous ridges,
supporting in part the calcareous system of the capillitium; capillitium
of delicate, rigid, reticulating yellow tubules or threads with numerous
free, uncinate or sickle-shaped branchlets, and large, irregular,
calcareous plates, more or less transverse to the axis of the
sporangium, attached to the peridial walls, as if to form septa,
ordinary calcareous nodules few; spore-mass jet-black, spores, by
transmitted light, violaceous, minutely roughened, 9-10 mu.
A very rare species, as it appears, easily recognized by the Coddington
even, much more by the microscopic characters quoted; probably often
overlooked by the collector, as to the naked eye it presents the
appearance of some imperfectly developed, dried-up plasmodium. Very
unlike _Physarum serpula_ Morgan, not infrequently offered by collectors
as _Cienkowskia_. It is _Diderma reticulatum_ of Fries, who, strangely
enough, thought it might be a plasmodial phase of _Diderma_ (i. e.
_Leocarpus_) _fragile_ (_Syst. Myc._, III., p. 102).
Eastern United States, Europe, Java, Ceylon, California. See under _L.
fragilis_, next following.
=7. Leocarpus= (_Link_) _Rost._
1809. _Leocarpus_ Link, _Diss._, I., p. 25.
Sporangia sessile, or short stipitate; peridial wall double, the outer
thick, destitute of lime, polished, shining within and without, the
inner very delicate, enclosing the capillitium and spores; capillitium
of two, more or less, distinct systems, the one a delicate network of
hyaline, limeless threads, the other calcareous throughout, or nearly
so, the meshes large and the threads or tubules broad; columella none,
although a pseudo-columella may sometimes be detected.
This genus was by Link established on characters purely external.
Rostafinski supplemented Link's definition by calling attention to the
peculiar character of the capillitium and to microscopic characters in
general. The outer peridium is thick and strong, unlike the ordinary
structure in _Physarum_. Some physarums, however, have a very similar
outer wall; _P. brunneolum_, for instance; compare the peridium of _P.
citrinellum_. In dehiscence and structure there is also some resemblance
to some species of _Diderma_, and by Persoon and Fries the common
species was so referred, but the capillitium is again definitive.
A critical study of all these things really begins with Rostafinski's
microscope. Under his definition of the present genus _P. squamulosum_
Wingate and _P. albescens_ Ell. might well be entered here. Such course
at present would but increase confusion, and until by future research
the ontogeny of all these, and so their relationship, shall be
more exactly known, the genus may be left with its historic
species,--montotypic.
LEOCARPUS FRAGILIS (_Dickson_) _Rost._
PLATE VIII., Figs. 3, 3 _a_, 3 _b_.
1785. _Lycoperdon fragile_ Dickson, _Fasc. Pl. Crypt. Brit._, I.,
p. 25.
1795. _Diderma vernicosum_ Persoon, _Ust. Ann. Bot._, XV., p. 34.
1809. _Leocarpus vernicosum_ Link, _Diss._, I., p. 25.
1875. _Leocarpus fragilis_ (Dicks.) Rost., _Mon._, p. 132.
Sporangia gregarious or clustered, sessile or stipitate, obovoid, rusty
or spadiceous-yellow, shining; peridium opening at maturity in somewhat
stellate fashion; stipe filiform, white or yellow, weak and short;
spores dull black, spinulose, 12-14 mu.
A common species, distributed through all the world, Iowa to Tasmania.
Recognizable at sight by the form and color of the sporangia. In shape
and posture these resemble the eggs of certain insects, and, occurring
upon dead leaves, generally where these have drifted against a rotten
log, they might perchance be mistaken for such structures. With no other
slime-moulds are they likely to be confused. The outer peridium opens
irregularly, or more rarely stellately. At centre of the capillitium is
a calcareous core. The plasmodium is yellowish white, spread in rich and
beautiful reticulations. _N. A. F._, 1123.
A plasmodiform gathering of this species which will be mistaken for an
entirely different thing, is yellow, sessile, and has _adherent_ spores;
looks like a badhamia, but is after all a leocarpus and probably belongs
here. The spores are irregularly clustered and the badhamioid section of
the capillitium seems now dominant.
California.
B. DIDYMIACEAE
=Key to the Genera of the Didymiaceae=
1. Fructification aethalioid 1. _Mucilago_
2. Fructification plasmodiocarpous, or forming more
often distinct sporangia.
_a._ Calcareous deposits crystalline, stellate 2. _Didymium_
_b._ Calcareous deposits amorphous, peridium double 3. _Diderma_
_c._ Calcareous deposits in form of scattered
scales 4. _Lepidoderma_
_d._ Peridium double, the outer gelatinous 5. _Colloderma_
=1. Mucilago= (_Mich._) _Adans._
1729. _Mucilago_ Micheli, _Nov. Pl. Gen._, in part.
1763. _Mucilago_ (Mich.) Adanson, _Fam. des Pl._, II., p. 7.
1791. _Spumaria_ Pers. in Gmelin, _Syst. Nat._, II., p. 1466.
Fructification aethalioid, consisting generally of large cushion-shaped
masses covered without by a white foam-like crust; within, composed of
numerous tubular sporangia, developed from a common 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 occasional swellings or thickenings.
By the descriptions offered by most authors, and especially by
Rostafinski's figures (_Mon._, Pl. ix.), a pronounced columella is
called for in the structure of _Spumaria_. The individual sporangia rise
from a common hypothallus, and occasionally portions of this run up and
give to a sporangium the appearance of being stipitate. Sometimes also
this upper extension of the hypothalline protoplasm passes beyond or
behind the base of the sporangium or between two or more, and is more or
less embraced by these in their confluent flexures. This, it seems,
suggested Rostafinski's elaborate diagram, Fig. 158; at least, none
other form of columella is shown by American materials at hand.
1. MUCILAGO SPONGIOSA (_Leyss._) _Morgan._
PLATE VII, Figs. 6, 6 _a_, 6 _b_.
1783. _Mucor spongiosus_ Leysser, _Fl. Hal._, p. 305.
1791. _Reticularia alba_ Bull., _C. Fl. France_, p. 92.
1791. _Spumaria mucilago_ Pers., Gmel., _Syst. Nat._, II., 1466.
1805. _Spumaria alba_ (Bull.) DC., _Fl. Fr._, II., p. 261.
1897. _Mucilago spongiosa_ (Leyss.) Morg., _Bot. Gaz._, XXIV., p. 56.
Aethalium white or cream-colored, of variable size and shape,
half-an-inch to three inches in length and half as thick, the component
sporangia resting upon a common hypothallus and protected by a more or
less deciduous calcareous porous cortex; peridial walls thin, and where
exposed iridescent, generally whitened by a thin coating of lime
crystals; capillitium scanty, of simple, mostly dark-colored, slightly
anastomosing threads; columella indefinite or none; hypothallus white,
spongy; spore-mass black, spores violaceous, exceedingly rough, large,
12-15 mu.
Very common in all the eastern United States and the Mississippi valley,
south to Texas. The plasmodium is dull white, of the consistence of
cream, and is often met with in quantity on beds of decaying leaves in
the woods. In fruiting the plasmodium ascends preferably living stems of
small bushes, herbaceous plants, or grasses, and forms the aethalium
around the stem some distance above the ground. The cortex varies in
amount, is also deciduous, so that weathered or imperfectly developed
forms probably represent the var. _S. cornuta_ Schum.
Two varieties of this species are recognized; the one from Bolivia, var.
_dictyospora_ described by Mr. R. E. Fries (_Arkiv. for Botanik_ Bd. 1,
p. 66) differs from the type chiefly in its finer capillitial threads
its darker spores with longer spines and fine reticulate sculpture; the
other from Colorado, var. _solida_ described by Professor Sturgis
differs, as the name implies, principally in its greater compactness and
slightly smaller calcareous crystals; a desert phase.
=2. Didymium= (_Schrad._) _Fr._
1797. _Didymium_ Schrad., _Nov. Gen. Plant._, p. 20, in part.
1829. _Didymium_ (Schrad.) Fr., _Syst. Myc._, III., p. 113.
1875. _Didymium_ (Schrad.) DeBy., Rost., _Versuch_, p. 13.
Sporangia distinct, stipitate, sessile or even plasmodiocarpous, never
aethalioid; the peridium thin, irregular in dehiscence, covered 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.
The genus _Didymium_, as set up by Schrader _l. c._, included a number
of species now assigned to _Diderma_, _Lepidoderma_ or _Lamproderma_.
Fries set out the didermas; DeBary and Rostafinski completed the
revision by setting out the remaining alien forms.
The genus is among Myxomycetes instantly recognized by the peculiar form
of its calcareous deposits, stellate crystals coating, or merely
frosting, usually distinct sporangia.
=Key to the Species of Didymium=
1. Lime-crystals merely whitening the peridial wall.
A. Fructification plasmodiocarpous.
_a._ White.
O Capillitium with adherent vesicles 1. _D. complanatum_
OO Capillitium simple 2. _D. anellus_
OOO Capillitium much combined; spores
10-13 mu 3. _D. wilczekii_
OOOO Capillitium crystal-bearing 18_a_. _D. anomalum_
_b._ Yellow or tawny 4. _D. fulvum_
B. Fructification normally of distinct sporangia.
_a._ Sporangia sessile or nearly so; outer
calcareous wall conspicuously developed 5. _D. crustaceum_
_b._ Sporangia plainly stipitate.
i. Peridium much depressed; umbilicate below.
O Stipe white 6. _D. squamulosum_
OO Stipe black.
+ Larger, about 7.5-1 mm. 7. _D. melanospermum_
++ Small, about .5 mm. 8. _D. minus_
+++ Sporangia discoid 9. _D. clavus_
ii. Peridium small, globose.
O Stipe dark brown or black; columella
dark, obsolete or none. 10. _D. nigripes_
OO Stipe generally paler, of various tints
of brown, orange, etc.
+ Columella pale or white, nearly
smooth 11. _D. xanthopus_
++ Columella, yellow, discoid, rough 12. _D. eximium_
iii. Peridium turbinate, columella
hemispheric 13. _D. trochus_
iv. Peridium annulate 14. _D. annulatum_
2. Calcareous crystals forming a distinct crust.
A. Fructification wholly plasmodiocarpous 15. _D. dubium_
B. Sporangia ill-defined, sessile, plasmodiocarpous.
_a._ Spores generally nearly smooth 16. _D. difforme_
_b._ Spores very rough, obscurely banded 17. _D. quitense_
EXTRA-LIMITAL
_a._ Sporangia discoid, spores reticulate 18. _D. intermedium_
_b._ Stipe, columella, peridium, orange-brown 19. _D. leoninum_
1. DIDYMIUM COMPLANATUM (_Batsch_) _Rost._
PLATE XVI., Fig. 8.
1786. _Lycoperdon complanatum_ Batsch, _Elench. Fung._, I., p. 251.
1829. _Didymium serpula_ Fr., _Syst. Myc._, III., p. 126, Rost.,
_App._, p. 21.
1875. _Didymium complanatum_ (Batsch), Rost., _Mon._, p. 151.
1899. _Didymium complanatum_ (Batsch) R., Macbr., _N. A. S._, p. 85.
1911. _Didymium complanatum_ Rost., List., _Mycetozoa, 2nd ed._,
p. 127.
Fructification plasmodiocarpous, creeping, flattened, vein-like,
annulate or reticulate, the dark-colored peridium covered with white,
but not numerous crystals; hypothallus none; columella none; capillitium
much branched, violaceous threads combined to form a rather dense net
which bears numerous, peculiar, rounded vesicles, yellowish in color,
30-50 mu in diameter; spores minutely warted, 7-9 mu, violaceous-brown.
The defining characteristics here are the curious supplementary
vesicles. These are evidently plasmodic, embraced, shot-through, by all
the neighboring capillitial threads, withal warted like a spore. They
remind of the curious, belated, spore-like but giant cells found in
stipes, as in arcyriaceous forms. With all the wealth of his prolix,
poetic, metaphoric tongue, the Polish author gives them abundant
consideration. In the _Mon._, Tab. IX., Figs. 166 and 180, he clearly
shows the structure, although in the explanation of the plate he has
strangely mixed this species with _D. crustaceum_ Fr. Under _D. serpula_
Fries may refer to the present species, although there is nothing in his
description to determine the fact. The same thing may be said of the
description and figures of Batsch. Rostafinski, in the _Monograph_,
seems to have been satisfied as to the identity of Batsch's materials:
in the _Appendix_, he writes _D. serpula_, but gives no reason.
Rare. New York. England, France, Germany.
2. DIDYMIUM ANELLUS _Morgan._
PLATE XVIII., Fig. 7.
1894. _Didymium anellus_ Morgan, _Jour. Cin. Soc._, p. 64.
1899. _Didymium anellus_ Morg., Macbr., _N. A. S._, p. 85.
1911. _Didymium anellus_ Morg., Lister, _Mycetozoa, 2nd ed._, p. 134.
Plasmodiocarp in small rings or links, then confluent and elongated,
irregularly connected together, bent and flexuous, resting on a thin
venulose hypothallus, or sometimes globose, the peridium dark colored,
with a thin layer of stellate crystals, irregularly ruptured;
capillitium of slender, dark-colored threads, which extend from base to
wall, more or less branched, and combined into a loose net; columella a
thin layer of brown scales; spores globose, very minutely warted,
violaceous, 8-9 mu.
This minute species resembles a poorly developed, or sessile, phase of
_D. melanospermum_. Some of the sporangia (?) are spherical; such show a
very short dark stalk. The columella is scant, and the spores are
smaller than those of _D. melanospermum_.
Ohio. Reported more recently from Europe and Ceylon.
3. DIDYMIUM WILCZEKII _Meylan_.
1908. _Didymium wilczekii_ Meyl., _Bull. Soc. Vaud. Sci. Nat._,
XLIV., p. 290.
1911. _Didymium wilczekii_ Meyl., List., _Mycetozoa, 2nd ed._, p. 134.
Plasmodiocarpous, dehiscing irregularly, columella scant; capillitium
abundant, the threads brown, anastomosing, forming an elastic net;
spores purple-brown, minutely spinulose, 10-12 mu.
Resembling plasmodiocarpous forms of _D. squamulosum_, a montane var.;
small and delicate, our specimen about 16 x 6 mm. Evidently not common;
collected but once by Professor Bethel at an altitude of 11,000 feet,
Rocky Mountains of Colorado.
Reported in Switzerland and Sweden.
In certain Swiss gatherings made in 1913 Miss Lister finds capillitial
threads with _spiral_ taeniae as in _Trichia_! (_Jour. of Bot._, Apr.
1914.) The threads in our specimen are roughened, somewhat as in _D.
squamulosum_, though less strongly; the spores are nearly smooth,
fuliginous at first, paler and violaceous when saturate.
4. DIDYMIUM FULVUM _Sturgis._
1917. _Didymium fulvum_ Sturgis, _Mycologia_, IX., p. 37.
Sporangia gregarious, sessile, elongate or forming curved
plasmodiocarps, sometimes confluent, rarely sub-globose, concave
beneath, pale-raw-umber in color, 0.5-0.8 mm. in diameter, occasionally
seated on a concolorous, membranous, lime-encrusted hypothallus which
may form pseudo-stalks; sporangium wall membranous, stained with yellow
blotches, thickly sprinkled with clusters of large acicular crystals of
pale-yellowish lime; columella very much flattened or obsolete;
capillitium an abundant network of delicate, almost straight or
flexuose, pale-purple or nearly hyaline threads, frequently with dark,
calyciform thickenings as in _Mucilago_, and occasionally showing
fusiform, crystalline blisters; spores dark-purplish-brown, coarsely
tuberculate, the tubercles usually arranged in curved lines, paler and
smoother on one side, 12.5 to 14.5 mu. Colorado.
5. DIDYMIUM CRUSTACEUM _Fr._
1829. _Didymium crustaceum_ Fr., _Syst. Myc._, III., p. 124.
Sporangia closely aggregated, globose, or by compression deformed,
sessile, snow-white, by virtue of the remarkably developed covering of
calcareous crystals by which each sporangium is surrounded as if to form
a crust, the peridium membranous, colorless, usually shrunken above and
depressed; columella pale, small, or obsolete; hypothallus scant or
vanishing; capillitium of rather stout violaceous threads seldom
branched except at the tips, where they are pale and often bifid, or
more than once dichotomously divided; spores strongly warted, globose,
violet-brown, 10-13 mu.
This species has in some ways all the outward seeming of a diderma, but
cannot be referred to that genus because of the crystalline character of
its crust. This is a very marked structure; loosely built up of very
large crystals, it is necessarily extremely frail, nevertheless
persists, arching over at a considerable distance above the peridium
proper. Sometimes, however, caducous, evanescent.
The sporangia are said to be sometimes stipitate. This feature does not
appear in any of the material before us. Lister in _Mycetozoa_ Pl. XL.,
_c._ draws the capillitium much more delicate than it appears in our
specimens. The hypothallus is sometimes noticeable under some of the
sporangia where closely crowded, but is not a constant feature.
Rostafinski (by typographical error?) confused in the _Monograph_, pp.
164, 165, this species with Persoon's _Physarum confluens_. In the
_Appendix_ he substitutes the Friesian nomenclature. Persoon's
description of his species is insufficient, and throws no light on the
problem whatever.
Rare. Iowa; Black Hills, South Dakota. Reported common in Europe.
Canada; Vancouver Island to the St. Lawrence.
6. DIDYMIUM SQUAMULOSUM (_Alb. & Schw._) _Fries._
1805. _Diderma squamulosum_ Alb. & Schw., _Consp. Fung._, p. 88.
1816. _Didymium effusum_ Link, _Diss._, II., p. 42.
1829. _Didymium squamulosum_ (Alb. & Schw.), Fries, _Syst. Myc._,
III., p. 118.
1875. _Didymium effusum_ (Link) Rost., _Mon._, p. 163.
1894. _Didymium effusum_ (Link) List., _Mycetozoa_, p. 99.
Sporangia, in typical forms, gregarious, globose or depressed-globose,
gray or snow-white, stipitate; the peridium a thin iridescent membrane
covered more or less richly with minute crystals of lime; the stipe when
present, snow-white, fluted or channelled, stout, even; columella white,
conspicuous; hypothallus usually small or obsolete; capillitium of
delicate branching threads, usually colorless or pallid, sometimes with
conspicuous calyciform thickenings; spores violaceous, minutely warted
or spinulose, 8-10 mu.
This, one of the most beautiful species in the whole series, is
remarkable for the variations which it presents in the fruiting phase.
These range all the way from the simplest and plainest kind of a
plasmodiocarp with only the most delicate frosting of calcareous
crystals up through more or less confluent sessile sporangia to
well-defined elegantly stipitate, globose fruits, where the lime is
sometimes so abundant as to form deciduous flaky scales. The
hypothallus, sometimes entirely wanting, is anon well developed, even
continuous, venulose, from stipe to stipe. The capillitium varies much
in abundance as in color; when scanty, it is colorless and in every way
more delicate, when abundant, darker in color and sometimes with
stronger thickenings.
_D. fuckelianum Rost._, as shown in _N. A. F._, 2090, and in some
private collections, seems to be a rather stout phase of the present
species; the stipe is more abundantly and deeply plicate, is sometimes
tinged with brown, and the capillitium is darker colored and coarser
than in what is here regarded as the type of the species; but withal the
specimens certainly fail to meet the requirements of Rostafinski's
elaborate description and figure, _Mon._, p. 161 and Fig. 154.
_D. effusum_ Link, probably stands for a sessile form of this species,
but Link's brief description (1816) is antedated by the much better one
of Albertini and Schweinitz, _l. c._
Generally distributed throughout the wooded regions of North America,
from New England to Nicaragua, and from Canada to California. Not
uncommon about stable-manure heaps, in flower beds, and on richly
manured lands. July, August.
Nicaragua specimens not only show a continuous vein-like hypothallus,
but have the peridia often confluent, the columellae in such cases
confluent, the stipes distinct. Furthermore, the largest spores reach
the limit of 12.5 mu, and perhaps the larger number range from 10-12.5 mu,
and all are very rough. This corresponds with _D. macrospermum_ Rost.,
which is distinguished, says the author (_Mon._, p. 162, _opis_),
"chiefly by the large and strongly spinulose spores." However, the same
sporangium in our Central American specimens yield spores 9.5-12.5 mu, a
remarkable range. So that _D. macrospermum_ on this side the ocean, at
least, cannot be distinguished from _D. squamulosum_, as far as spores
are concerned. A similar remark may be made relative to the form of the
columella which Rostafinski, in his figures especially, would make
diagnostic. The columella in the sporangia with largest and roughest
spores is that of a perfectly normal _D. squamulosum_.
7. DIDYMIUM MELANOSPERMUM (_Pers._) _Macbr._
PLATE VII., Figs. 3, 3 _a._
1794. _Physarum melanospermum_ Pers., _Roem. N. Mag. Bot._, p. 89.
1797. _Didymium farinaceum_ Schrader, _Nov. Gen. Pl._, p. 26, t. 5,
Fig. 6.
Sporangia gregarious, hemispheric, depressed, umbilicate below,
stipitate or sessile; the peridium firm, dull brown in color, frosted
with minute crystals of lime, breaking irregularly; stipe, when present,
short, stout, dull black, opaque, arising from a broad base or
hypothallus; columella large, prominent; dark-colored, rough above,
concave below; capillitium of more or less sinuous, usually dark-colored
threads, sparingly branched, and often with calyciform thickenings;
spore-mass black, spores by transmitted light pale, purplish-gray,
spinulose or rough, 10-12 mu.
A well-marked and common species, distinguished by its depressed
sporangium and dark-colored, opaque stipe. The latter is usually very
short, almost completely concealed in the concavity of the umbilicate
sporangium. The columella is dark-colored, forming the floor of the
peridial cavity.
Persoon first named this species as here. Later on, _Uster's Ann._, XV.,
6, he substituted _villosum_ as a more appropriate specific name.
Schrader rejects both names given by Persoon as unsuitable, and suggests
_farinaceum_. Schrad., _op. cit._, p. 27.
New England, Ohio, Missouri, Alabama, Iowa, Nebraska; Europe; probably
cosmopolitan.
8. DIDYMIUM MINUS _Lister._
PLATE X., Figs. 4, 4 _a_, 4 _b_.
1892. _Didymium farinaceum_ Schr., var. _minus_, List., _Mycetozoa_,
p. 97.
1896. _Didymium minus_ List., Morg., _Jour. Cin. Soc._, p. 61.
1899. _Didymium minus_ List., Macbr., _N. A. S._, p. 89.
Sporangia gregarious, depressed-globose, umbilicate below, whitish or
gray, small, about 1/2 mm., stipitate; stipe erect, rather slender,
black, faintly striate, about equal to the sporangium in the horizontal
diameter; columella distinct, dark brown, globose or depressed-globose,
attaining in some cases the centre, rough; capillitium delicate, almost
colorless, radiating, sparsely branched; spores in mass dark brown, by
transmitted light violet-tinted, minutely roughened, 8-10 mu.
Probably more common than the preceding, and generally mistaken for it.
Distinguished by its smaller size, longer and more slender stem, and
general trim, well-differentiated appearance. Certainly very near the
preceding, of which Mr. Lister regards it as merely a variety. Professor
Morgan thought it in this country the more common form.
New York, Ohio, Iowa; reported from Europe, Africa, South America.
9. DIDYMIUM CLAVUS (_Alb. & Schw._) _Rabenhorst._
1805. _Physarum clavus_ Alb. & Schw., _Consp. Fung._, p. 96.
1829. _Didymium melanopus_ Fries, _Syst. Myc._, III., p. 114.
1844. _Didymium clavus_ (Alb. & Schw.) Rabh., _Ger. Cr. Fl._,
No. 2282.
1875. _Didymium clavus_ (Alb. & Schw.) Rost., _Mon._, p. 153.
1899. _Didymium clavus_ (Alb. & Schw.) Rabenh., Macbr., _N. A. S._,
p. 90.
1911. _Didymium clavus_ Rost., List., _Mycet., 2nd ed._, p. 128.
Sporangia gregarious, pale gray, discoid or pileate, depressed,
stipitate; the peridium dark-colored, frosted with calcareous crystals
above, naked below; stipe short, slender, tapering upward, furrowed,
arising from a hypothallus more or less distinct, black; columella
obsolete; capillitium of delicate threads, pale or colorless, little
branched; spores violaceous, pale, nearly smooth, 6-8 mu.
This species is well differentiated, easy of recognition by reason of
its peculiar discoid sporangium, calcareous above, naked and black
beneath. _D. neglectum_ Massee, reported from Philadelphia, is said to
be a slender form of the present species. The figures of _D. clavus_ by
Albertini and Schweinitz are excellent, as also the description.
Not common. Pennsylvania, Ohio, Iowa.
10. DIDYMIUM NIGRIPES (_Link_) _Fries._
PLATE VII., Figs. 2, 2 _a_, 2 _b_.
1809. _Physarum nigripes_ Link, _Obs. Diss._, I., p. 27.
1818. _Physarum microcarpon_ Fr., _Sym. Gast._, p. 23.
1829. _Didymium nigripes_ (Link) Fr., _Syst. Myc._, III., p. 119.
1875. _Didymium microcarpon_ (Fr.) Rost., _Mon._, p. 157.
1896. _Didymium microcarpon_ Fr., Morg., _Jour. Cin. Soc._, p. 61.
Sporangia gregarious, globose or hemispheric, umbilicate beneath, small,
white, stipitate; the peridium smoky, covered with minute calcareous
crystals; stipe slender, erect, black, opaque; hypothallus scutate,
black; columella distinct, globose, black or dark brown; capillitium of
delicate threads, pale brown or colorless, with occasional brown
thickenings or nodes, sparingly branched; spores pale, violaceous by
transmitted light, minutely warted, 6-8 mu.
This is _D. microcarpon_ Rost. Fries, _l. c._, acknowledges the priority
of Link's appellation, and discards _microcarpon_. Rostafinski adopted
_microcarpon_ simply because he thought it more appropriate. Fries
describes the columella "none or black." It is doubtful whether we have
the typical Friesian form on this continent. The fructification is in
our specimens small, about .4 mm., and the spores, as noted by Morgan,
small; otherwise the species is hardly more than a variety of the next.
Under the name _D. nigripes_ Lister groups our Nos. 10, 11, 12. _N. A.
F._, 1393, represents Dr. Rex's conception of the present species.
Not common. New York, Ohio, Iowa.
11. DIDYMIUM XANTHOPUS (_Ditmar_) _Fr._
PLATE XVI., Fig. 10.
1817. _Cionium xanthopus_ Ditmar, Sturm, _Deutsch. Fl._, III., p. 37,
t. 43.
1829. _Didymium xanthopus_ (Dit.) Fr., _Syst. Myc._, III., p. 120.
1873. _Didymium proximum_ Berk. & C., _Grev._, II., p. 52.
1892. _Didymium microcarpon_ (Fr.) Rost., Macbr., _Bull. Lab. Nat.
Hist. Iowa_, II., p. 146, in part.
1894. _Didymium nigripes_ Fr., List., _Mycetozoa_, p. 98, in part.
Sporangia gregarious, white, globose, slightly umbilicate, stipitate;
the peridium thin, and nearly or quite colorless, frosted with crystals
of lime; the stipe yellowish or yellowish brown, corneous, erect,
subulate, slender; hypothallus none; columella pale or white,
turbinate, globose or depressed-globose; capillitium of dull brown, or
colorless threads more or less branched, always white at the tips;
spores violaceous, nearly smooth, 7.5-8.5 mu.
This seems to be the most common form in the United States. It is
distinguished from the preceding by the longer, more delicate, generally
orange-yellow, stem with pale or white columella. The spores also
average a shade larger. _N. A. F._, 412 and 2089, are illustrations of
_D. xanthopus_. The columella in blown-out specimens is very striking,
well confirming the diagnosis of Fries, "_valde prominens, globosa,
stipitata, alba_." Berkeley makes the color of the capillitium
diagnostic of _D. proximum_, but this feature is insufficient.
Eastern United States; common.
12. DIDYMIUM EXIMIUM _Peck._
PLATE XVI., Figs. 11, 11 _a_, 11 _b_.
1879. _Didymium eximium_ Peck, _Rep. N. Y. Mus._, XXXI., p. 41.
Sporangia scattered, dull grayish-yellow or gray, depressed-globose,
umbilicate, minute, stipitate; the peridium comparatively thick,
tenacious, especially persistent below, tawny or yellow; the stipe pale
brown or orange, erect, even or slightly enlarged at base; hypothallus
scant or none; columella prominent, more or less discoidal, rough, or
spinulose, especially on the upper surface, yellow; capillitium not
abundant, pale fuliginous, often branching and anastomosing so as to
form a loose net; spores nearly smooth, dark violaceous by transmitted
light, 8.5-9.5 mu.
The species differs from _D. xanthopus_ in several particulars,--in the
much firmer, more persistent, and less calcareous peridium, in the more
complex capillitium, in the darker and larger spores, and especially in
the peculiar and prominent columella, which is not only rough, but even
"sometimes spinulose even to the extent of long spicules penetrating to
one-third the height of the sporangia." _N. A. F._, 2493.
As stated under No. 8, these last two species are called varieties only
of _D. nigripes_. They are so retained in _Mycetozoa, 2nd ed._ Since,
however, they are the usual presentation of the species in the United
States, it seems wise to let them stand for the present, as here. They
are quite distinguishable; _D. eximium_ especially well marked.
Apparently rare, it yet ranges from New York to eastern Iowa, in
colonies rather large. Okoboji Lake;--fine!
13. DIDYMIUM TROCHUS _List._
1898. _Didymium trochus_ List., _Jour. Bot._, XXXVI., p. 164.
Sporangia plasmodiocarpous, hemispherical or turbinate, white, sessile
or very short-stalked, cream-colored or white; peridium double, the
outer shell-like, the inner membranaceous, more or less adherent to the
outer, both caducous together, leaving the thickened base surrounding an
expanded columella; stipe, when present, very short, stout; capillitium
colorless, nearly simple; spores brownish-purple, strongly warted, 9-10
mu.
On decaying leaves, rotten cactus, yucca, etc., Monrovia, California;
_Bethel_.
Reported from England on beds of leaves or straw; in Portugal Dr.
Torrend finds it on or _in_ dead leaves of _Agave americana_! Evidently
an American species, and belonging to arid regions; its occurrence in
England surprising!
14. DIDYMIUM ANNULATUM _Macbr. n. s._
PLATE XX., Figs. 4, 4 _a_.
Sporangia small, scattered, annulate, not only without columella but
perforate when the stipe is broken, umbilicate above and below, grey,
coated with crystalline frustules, opening irregularly about the
periphery; stipe white, or pallid, fluted, tapering upward from a
distinct hypothallus; capillitium scanty consisting of delicate,
sparsely branching threads, the branchlets anastomosing more or less at
length, attached to the peridial wall, radiating from the rim of the
slightly depressed top of stipe, without special thickenings save at the
insertion of the ramules a triangular enlargement is usual and of dark
or pallid shade; spores smooth; however they show three or four spots
on the hemisphere and other minute but variable markings; 9-10 mu.
Seattle, Washington.
Differs from _D. nigripes_ in color of the stipes, capillitium,
spore-diameter, etc.
15. DIDYMIUM DUBIUM _Rost._
1875. _Didymium dubium_ Rost., _Mon._, p. 152.
1892. _Didymium listeri_ Mass., _Mon._, p. 244.
1894. _Didymium dubium_ Rost., List., _Mycetozoa_, p. 95.
1911. _Didymium dubium_ Rost., List., _Mycetozoa, 2nd ed._, p. 126.
Fructification wholly plasmodiocarpous, snow-white, small,
2-6 mm., flat and thin; the outer wall double, membranous within,
calcareous-crystalline without; columella none; capillitium simple of
rather thick, vertical, brown threads, sparingly united laterally, and
only occasionally furcate at the ends, especially above; spores minutely
spinulescent, violaceous pale, 12-15 mu.
Massee thought English specimens out of harmony with the original
description and gave them a new name. To refuse this, Lister enlarges
the range of spore-measurements and disregards some of Rostafinski's
specifications as to capillitium. Our specimens are as described.
Bohemia. England. Shores of Lake Okoboji, Iowa.
This is indeed a doubtful form. It differs from _D. difforme_ chiefly in
that the outer calcareous shell is not smooth, but is covered with
abundant loose crystals, frosted. The spores are paler but about the
same size. The frosting may be incident to local climatic conditions at
the time and place of desiccation.
16. DIDYMIUM DIFFORME _Duby._
1797. _Diderma difforme_ Pers. _Tentamen Disp. Meth._, p. 19.
1830. _Didymium difforme_ Duby., _Bot. Gall._, ii., p. 858.
1875. _Chondrioderma difforme_ Pers., Rost., _Mon._, p. 177.
1894. _Didymium difforme_ Duby., List., _Mycetozoa_, p. 94.
1899. _Diderma personii_ Macbr., _N. A. S._, p. 96.
1911. _Didymium difforme_ Duby., List., _Mycetozoa, 2nd ed._, p. 124.
Plasmodiocarpous, the smooth, white outer peridium separable from the
thin, colorless or purplish inner layer; capillitium of rather coarse,
flat, dichotomously branching threads, broader below; spores minutely
warted, or almost smooth, dark brown, 12-14 mu.
The white crust-like outer wall has more than once carried this species
into _Diderma_. It is still doubtful whether we are here dealing with
_Chondrioderma calcareum_ Rost. Miss Lister cites a variety, _S.
difforme comatum_, with more abundant capillitium which may represent
Rostafinski's species.
Evidently rare in the United States; reported more common in Europe and
eastward. In our specimens the crust-like outer peridium shows crystals
on the broken edge only; the body of the object, as its outer surface
seems to be amorphous.
17. DIDYMIUM QUITENSE (_Pat._) _Torr._
1895. _Chondrioderma quitense_ Pat., _Bull. Soc. Myc. Fr._, XI.,
p. 212.
1909. _Didymium quitense_ (Pat.) Torr., _Flor. Myxom._, p. 150.
1911. _Didymium quitense_ Torr., List., _Mycetozoa, 2nd ed._, p. 126.
1913. _Didymium quitense_ (Pat.) Torr., Sturg., _Myx._, Col. II.,
p. 446.
Sporangia more or less plasmodiocarpous, scattered, depressed, white;
the outer peridium distinct, crust-like, remote from the thin membranous
inner wall; columella undefined; capillitium brown, much branched,
forming a network especially outwardly; spores very dark
violaceous-brown, rough with a tendency to obscure reticulation; 12-14
mu.
This species is different from _D. difforme_ chiefly in the rougher and
somewhat banded epispore. It is reported from Ecuador by Father Torrend,
and from Colorado mountains by Dr. Sturgis to whose kindness I am
indebted for the specimens here described. Evidently a high mountain
species.
Colorado.
18_a_. DIDYMIUM ANOMALUM _Sturg._
PLATE XIX., Figs. 13 and 13 _a_.
1913. _Didymium anomalum_ Sturg. _Myxomycetes of Col._, II., p. 444
Sporangia in the form of very thin effused grey plasmodiocarps, 2-10 cm.
long, 1 mm. or less in thickness. Wall single or membranous, hyaline or
yellowish, with rather scanty deposits of small, stellately crystalline
or amorphous lime. Columella none. Capillitium consisting entirely of
straight membranous, tubular, columns, extending from the base to the
upper wall of the plasmodiocarp, 7-22 mu thick and usually containing
small crystalline masses of lime. Spores bright violet-brown, minutely
and irregularly spinulose, 10-11.5 mu diam.
Hab. on the inner bark of Populus. Colorado Springs, Colo., July 1911.
Our specimens by the courtesy of Dr. Sturgis.
=EXTRA-LIMITAL=
18. DIDYMIUM INTERMEDIUM _Schroeter._
1896. _Didymium intermedium_ Schroet., _Hedwigia_, Vol. XXXV., p. 209.
1902. _Didymium excelsum_ Jahn, _Ber. Deut. Bot. Ges._, XX., p. 275.
Sporangia clustered or gregarious, discoidal and umbilicate below, or
lobed or convolute, greyish white, stipitate; stipe pale yellow,
tapering upwards, stuffed with lime crystals, expanding into the
yellowish, discoidal, recurving columella; capillitium colorless, more
or less branching; spores dark purple-brown, irregularly reticulate,
9-12 mu.
Differs from _D. squamulosum_ in the reticulate epispore. Brazil.
19. DIDYMIUM LEONINUM _Berk. & Br._
1873. _Didymium leoninum_ Berk. & Br., _Jour. Linn. Soc._, XIV.,
p. 83.
1876. _Lepidoderma tigrinum_ Rost., _App. to Mon._, p. 23.
1909. _Lepidodermopsis leoninus_ v. Hoehnel, _Sitz. K. Ak. Wiss. Wien,
Math. Nat. Ks._, CXVIII., 439.
Sporangia gregarious, sub-globose, covered more or less completely with
white or yellowish deposits of crystalline lime, stipitate; stipes
short, orange or brown, containing lime, enlarged to form the globose
orange columella and often connected at base by a venulose hypothallus;
capillitium of slender threads, anastomosing, colorless at the tips;
spores violet-grey, minutely warted, 7-9 mu.
Like _Lepidoderma tigrinum_, but has different calcic crystals.
Java and Ceylon.
=3. Diderma= _Persoon_
1794. _Diderma Persoon_, _Roem. N. Mag. Bot._, I., p. 89.
1873. _Chondrioderma_ Rost. _Versuch_, p. 13, _Mon._, p. 167.
1894. _Chondrioderma_ Rost., List., _Mycetozoa_, p. 75.
1899. _Diderma Persoon_, Macbr., _N. A. S._, p. 92.
Sporangia plasmodiocarpous or distinct, sessile or stipitate; the
peridium as a rule double, the outer wall generally calcareous with the
lime granules globular, non-crystalline, the inner wall very delicate
and often, in the mature fructification, remote from the outer;
columella generally prominent.
The genus _Diderma_ is usually easy of recognition, by reason of its
double wall, the outer, crustaceous, usually calcareous, and its limits
remain substantially as originally set by Persoon. His definition is as
follows:--
"Peridium ut plurimum duplex; exterius fragile; interius pellucens,
subdistans. Columella magna, subrotunda. Fila parca latentia."--_Syn.
Meth. Fung._, p. 168.
Rostafinski changed the name of the genus to _Chondrioderma_ (_chondri_,
cartilage), seemingly at De Bary's suggestion, and seems to have
regarded Persoon's definition as applicable to those species only in
which the wall is not only plainly double, but in which the two walls
are as plainly remote from each other. More especially he esteemed a new
generic name necessary, since he regarded several included species, as
_D. spumarioides_, _D. michelii_, etc., monodermic.
Since it is doubtful whether any diderma is really monodermic, and since
Persoon's definition in any case seems sufficiently elastic, we have
seen no reason to discard the older name. Persoon's _Diderma_ when
established, _l. c._, included _D. floriforme_. He made some confusion
in his later work by admitting some physarums. This induced Schrader to
throw all the didermas into his new genus, _Didymium_.
According to the nature of the sporangial wall, the species fall rather
naturally into two sections:--
_A._ Outer sporangial wall distinctly calcareous, fragile;
species generally sessile _Diderma_
_B._ Outer sporangial wall cartilaginous, the inner less
distinct, or concrete with the outer; species
oftener stipitate _Leangium_
_A._ Sub-Genus DIDERMA
1. Fructification wholly plasmodiocarpous 1. _D. effusum_
2. Fructification of distinct sporangia.
_a._ Sporangia on a common hypothallus.
O Outer wall fragile, not widely remote from
the inner 2. _D. spumarioides_
OO Inner wall lacking 3. _D. simplex_
OOO Outer wall crustaceous, porcelain-like.
i. Spores 8-10 4. _D. globosum_
ii. Spores 12-15 5. _D. crustaceum_
OOOO Outer wall firm, not crustaceous 6. _D. lyallii_
_b._ Sporangia isolated, or, at least, not on a common hypothallus,
sessile.
O Outer wall porcellanous, roseate 7. _D. testaceum_
OO Outer wall white 8. _D. niveum_
OOO Outer wall ashen 9. _D. cinereum_
_c._ Sporangia stipitate 10. _D. hemisphericum_
_B._ Sub-Genus LEANGIUM
1. Sporangia generally sessile.
_a._ Inner peridium distinct.
O Membranous colorless, columella scant 11. _D. sauteri_
OO Colorless, columella prominent, red 12. _D. cor-rubrum_
OOO Outer ochraceous, inner yellow 13. _D. ochraceum_
_b._ Peridial layers inseparable.
O Peridium multifid; columella small
or none 16. _D. trevelyani_
OO Peridium breaking into but few irregular lobes; columella
prominent.
i. Peridium umber brown 14. _D. roanense_
ii. Peridium ashen 15. _D. radiatum_
iii. Peridium chocolate without,
inside white 17. _D. asteroides_
2. Sporangia stipitate.
_a._ Peridium pallid, smooth 18. _D. floriforme_
_b._ Peridium white, rugulose 19. _D. rugosum_
1. DIDERMA EFFUSUM (_Schw._) _Morgan._
1831. _Physarum effusum_ Schw., _N. A. F._, p. 257.
1896. _Diderma effusum_ (Schw.) Morg., _Jour. Cin. Soc._, p. 71.
1899. _Diderma effusum_ (Schw.) Morg., Macbr., _N. A. S._, p. 94.
1899. _Diderma reticulatum_ Rost., Macbr., _N. A. S._, p. 95.
1911. _Diderma effusum_ Morg., Lister, _Mycetozoa, 2nd ed._, p. 102.
Fructification plasmodiocarpous, reticulate, creeping, applanate and
generally widely effused, white; the peridium thin, cinereous, covered
by a delicate, white, calcareous crust; the columella simply the base of
the plasmodiocarp, thin alutaceous; the capillitium pale, consisting of
short threads somewhat branched toward their distal extremities; spores
smooth, pale violaceous, 8-10 mu.
This is _Physarum effusum_ Schw., _vid. N. A. F._, No. 2297. It is
reported by Morgan from Ohio, and we have one specimen from eastern
Nebraska, so that it is probably of general distribution in the eastern
United States.
This species was in the previous edition distinguished from the
Rostafinskian _P. reticulatum_ with spores a little smaller, 6-8 mu, and
with a much stronger tendency to the formation of definite sporangia,
elongate indeed and branching but often globose or depressed globose.
This we may know as,
VAR. RETICULATUM Rost.
1875. _Chondrioderma reticulatum_ Rost., _Mon._, p. 170.
1894. _Diderma reticulatum_ (Rost.) Morg., _Jour. Cin. Soc._, p. 71.
Sporangia gregarious, generally rounded, not much depressed, flat,
sometimes, especially toward the margin of a colony, elongate, venulose
or somewhat plasmodiocarpous, dull white, the inner peridium ashen or
bluish, remote from the calcareous crust, which is extremely fragile,
easily shelling off; columella indistinguishable from the base of the
sporangium, thin, alutaceous; capillitium of short, generally colorless,
delicate, sparingly branching or anastomosing threads perpendicular to
the columella; spores black in mass, by transmitted light violet-tinted,
smooth, 6-8 mu.
Perhaps our most common form. Found in fall on dead twigs, leaves, etc.
Recognized by its rather large, white, depressed or flattened sporangia
tending to form reticulations, and hence suggesting the name. The lines
of fruiting tend to follow the venation of the supporting leaf; where
the sporangium is round, the columella is a distinct rounded or
cake-like body; where the fruit is venulose, the columella is less
distinct.
By these rounded forms we pass easily, as by a gate, to _D.
hemisphericum_, which, when wholly sessile, differs still in greater
diameter of the sporangia and in having somewhat larger spores. Usually
in such case the compared colony will show somewhere a very short and
stout but very real stipe supporting the discoid fruit.
Rostafinski divided the genus _Chondrioderma_, i. e. _Diderma_, into
three sections:--
_Monoderma_ to include those species in which the calcareous crust is
less distinct or connate with the true peridium.
_Diderma_, in which the two structures were plainly separate.
_Leangium_, used as in the present work. In his first section
Rostafinski placed _C. reticulatum_ and _C. michelii_; in the second,
_C. difforme_ and _C. calcareum_.
Lister has examined Rostafinski's type of _C. reticulatum_ and declares
that it has the usual didermic characters. Hence there is no doubt that
our small-spored American specimens are covered by Rostafinski's
description, No. 72. On the other hand, Lister makes _C. difforme_
(Pers.) Rost. a _Didymium_, by its crystalline coat. That species
therefore is removed from consideration in this connection. _C.
calcareum_ remains as applicable to American forms having the spores
10-12 mu, but according to the author of the species the capillitium is
abundant and definitive. Unhappily the type of _C. calcareum_ is lost
(Lister, _Mon._, p. 95), so that there is no other means of verification
than the description and Rostafinski's figure. Under these circumstances
we consider the name _calcareum_ inapplicable to any American forms we
have so far seen. See next species. As to the American species which
have been distributed as _C. calcareum_ (Lk.) Rost., they are, so far as
seen, referable to _D. reticulatum_ (Rost.), Morg. Here also belongs No.
1217, Ellis, _N. A. F._
New York, Pennsylvania, Ohio, Iowa, Nebraska. Probably to be found
throughout the eastern United States.
2. DIDERMA SPUMARIOIDES _Fries_.
1829. _Diderma spumarioides_ Fries, _Syst. Myc._, III., p. 104.
1833. _Physarum stromateum_ Link., _Handb._, III., p. 409.
1876. _Chondrioderma stromateum_ (Lk.) Rost., _App._, p. 18.
Sporangia sessile, crowded, spherical, or by mutual pressure irregular,
white; the peridium plainly double, but the layers adhering, the outer
more strongly calcareous, but very frail, almost farinaceous;
hypothallus more or less plainly in evidence, white or pale alutaceous;
columella distinct, though often small, globose, yellowish; capillitium
variable in quantity, sometimes abundant, brown, somewhat branching and
anastomosing outwardly, the tips paler; spores minutely roughened, dark
violaceous, about 10 mu.
This species has the outward seeming of a didymium, but is plainly
different as that genus is here defined, since the calcareous crust,
although inclined to be pulverulent, is made up of minute granules, not
crystals, of lime. The hypothallus is sometimes hardly discoverable,
anon well developed, out-spread, rugulose, far beyond the limits of the
fructification. In his _Monograph_, p. 175, Rostafinski includes here
_Physarum stromateum_ Link. In the Appendix he is inclined to raise
Link's form to the dignity of a distinct species, basing the diagnosis
upon the superposition of the sporangia in certain cases, a feature
entirely unknown to Link's description and of extremely uncertain value,
since by their crowding the sporangia are liable always to be pushed
above each other. We therefore regard _C. stromateum_ (Link) Rost. as a
synonym of the present species, as the description, Link, Handb., III.,
409, indicates, so far as it goes.
3. DIDERMA SIMPLEX (_Schroet._) _Lister._
1885. _Chondrioderma simplex_ Schroet., _Krypt. Fl. Schles._, III.,
1, p. 123.
1911. _Diderma simplex_ List., _Mycetozoa, 2nd ed._, p. 107.
"Plasmodium bright yellowish brown." Sporangia gregarious, sessile,
globose or depressed globose, .3-.5 mm., or anon plasmodiocarpous, brown
or brick-red when fresh, becoming paler, ochraceous, etc.; hypothallus
everywhere in evidence; columella ill-defined; capillitium scanty, the
threads delicate, pale, branching as they join the peridial wall; spores
dull violaceous, slightly roughened, 8-10 mu.
A rather crude, primitive representative of this beautiful genus. The
inner peridium seems to be lacking,--a comfort to Rostafinski! Rare. Our
best specimens are from New Jersey, by courtesy of Dr. C. L. Shear.
These went to fruit on leaves and branches of _Vaccinium_. It seems to
affect the heather of Europe, moorland, etc. I have also specimens from
the herbarium of the lamented Dr. Rex. These are more plasmodiocarpous,
but open beautifully by a median fissure as in _Physarum sinuosum_
Bull. In no American gathering that I have examined does the capillitium
show calcareous thickenings as described by the British text.
4. DIDERMA GLOBOSUM _Persoon._
PLATE VII., Figs. 5, 5 _a_.
1794. _Diderma globosum_ Pers., _Roem. N. Mag. Bot._, I., p. 89.
1875. _Chondrioderma globosum_ (Pers.) Rost., _Mon._, p. 180.
Sporangia more or less closely gregarious, sessile, globose or by mutual
pressure prismatic or polyhedral, white, the outer wall smooth,
polished, crustaceous, fragile, far remote from the inner, which is
thin, smooth, or rugulose, iridescent blue; hypothallus usually
pronounced and spreading beyond the sporangia, sometimes scanty or
lacking, columella variable, sometimes very small, inconspicuous,
sometimes large, globose, ellipsoidal, even pedicellate; capillitium
abundant, brown or purplish brown, branching and occasionally
anastomosing to form a loosely constructed superficial net; spores
globose, delicately spinulose, 8 mu.
This species seems rare in this country. We have specimens from Iowa. It
is distinguished by small spores and generally snow-white color.
Lister has thrown doubt upon Rostafinski's definition of this
form--_Mycetozoa_, p. 78. Almost everything distributed in the United
States under this name belongs in the next species. Reported also from
Ohio,--_Morgan._ Washington. But:--it should be found in Europe, where
first described!
There are two ways to meet the difficulty. In the first place it seems
probable that a small-spored form really hides somewhere in Europe. The
difference between the _Monograph_ measurement and the size admitted for
_D. crustaceum_ Pk., evidently considered by Mr. Lister as type and so
used in his illustration, Pl. 85, is too great to be esteemed merely an
error. That added .3 (Rost.) indicates caution, the average of several
measurements. Our _D. globosum_ may represent what the _Monograph_
describes.[32] In the second place we may as American students mistake
larger and more globular forms of something else, of _D. spumarioides_
Fr., whose spores are but little larger; or of _D. effusum_ (Schw.)
Morg., where the flattened plasmodiocarps anon splatter out to globose
drops of polished whiteness, and whose spores are 8 mu. But even here the
chances of error are small. In the species last named the columella or
sporangial base is alutaceous, not white; in Fries' species, while the
columella if present may be white, the peridial walls are different,
difficult to distinguish.
For these reasons, _D. globosum_ Pers. may stand, waiting further light
from Europe.
5. DIDERMA CRUSTACEUM _Peck._
PLATE VII., Fig. 7
1871. _Diderma crustaceum_ Peck, _Rep. N. Y. Mus._, XXVI., p. 74.
1889. _Chondrioderma crustaceum_ (Peck) Berl., _Sacc._, VII., p. 373.
Plasmodium at first watery, colorless, becoming at length milky white;
sporangia closely crowded or superimposed, in a cushion-like colony,
creamy white, globose, imbedded in the substance of the hypothallus, the
outer peridium smooth, delicate, crustaceous, fragile, remote from the
blue iridescent inner membrane; hypothallus prominent; columella
variable, generally present, globose; capillitium dark-colored, the
threads branching and combining to form a loose net; spore-mass black,
spores by transmitted light dark violaceous, delicately roughened, 12-15
mu.
Common. Readily to be distinguished from the preceding by the larger
spores and more crowded habit. New England west to Nebraska.
The didermas are generally delicately beautiful. The outer wall in the
present species is like finest unglazed china, softly smooth, and yet
not polished, often absolutely white, with porcellanous fracture. An
inter-parietal space separates the outer from the inner wall, so that
the former may be broken, bit by bit, without in the least disturbing
the underlying structure. The inner wall is ashen or gauzy iridescent
green, sending back all colors in reflected light. The spores are
violet, deeply so when fresh, the capillitium strong and likewise
tinted; the columella passing down and blending with the common
snow-white hypothalline base. The distinct habits of the two species are
represented in Figs. 5 and 7. In the one the distinct sporangia are
associated but not crowded; in the other all are massed together in
quite aethalioid fashion, forming circumambient, chalky masses of
considerable size, 2 or 3 cm., overcrowded, superimposed, where the
sporangia are regular in shape and size by reason of mutual pressure.
The plasmodium develops in forests and orchards, among decaying leaves,
but is inclined to rise as maturity draws near, to ascend some twig
erect, or the stem of a living plant to the height of several inches
where the sporangia at length appear "heaped and pent", an encircling
sheath, conspicuous after the fashion of a spumaria for which it is
indeed sometimes mistaken.
6. DIDERMA LYALLII (_Massee_) _Macbr._
PLATE XVIII., Figs. 5 and 5 _a_
1892. _Chondrioderma lyallii_ Massee, _Mon._, p. 201.
1894. _Chondrioderma lyallii_ Mass., List., _Mycetozoa_, p. 81.
1899. _Diderma lyallii_ Mass., Macbr., _N. A. S._, p. 99.
1911. _Diderma lyallii_ List., sub-species, _Mycetozoa, 2nd ed._,
p. 105.
Sporangia obovate, more or less closely crowded, white, stipitate, about
1 mm. in diameter, the outer peridium firm, stout, encrusted, especially
above, with granular masses of lime, the inner well developed, more or
less cartilaginous, opaque, yellow or buff-colored; hypothallus well
developed, venulose, white, passing up unchanged to form the short,
stout stipe and lower outer peridium; columella prominent, half the
height of the sporangium, brown; capillitium of short, brown threads,
rigid, much branched, forming a net, widened irregularly and especially
at the net-nodes; spore-mass black, spores by transmitted light bright
brown, rough, 15-17 mu.
A very distinct species; large, fine, showy sporangia in more or less
crowded clusters spring from a snow-white, common hypothallus. First
reported from western Canada. Our first specimens were collected by the
late Mr. Charles Irish, on the eastern slopes of the Sierras, in Nevada;
now coming in abundantly from all the western mountains to the Pacific.
7. DIDERMA TESTACEUM (_Schrad._) _Pers._
PLATE VII., 4, 4 _a_, and 4 _b_.
1797. _Didymium testaceum_ Schrad., _Nov. Gen. Plant._, p. 25.
1801. _Diderma testaceum_ Persoon, _Syn._, p. 167.
1873. _Chondrioderma testaceum_ (Schrad.) Rost., _Vers._, p. 13.
1874. _Diderma mariae-wilsoni_ Clinton, _Rep. N. Y. Mus._, XXVI.,
p. 74.
1899. _Diderma testaceum_ (Schrad.) Pers., Macbr., _N. A. S._, p. 99.
1911. _Diderma testaceum_ Pers., List., _Mycetozoa, 2nd ed._, p. 106.
Sporangia gregarious, sessile, depressed-spherical or sometimes
elongate, small, 1 mm. or less, rose-white, smooth, the outer peridium
crustaceous, rather thick and persistent, polished, slightly raised
above the inner, which is dull ashen and more or less wrinkled;
hypothallus none; columella prominent, hemispherical in the typical
rounded forms, slightly rough, reddish or reddish alutaceous;
capillitium usually abundant, of slender, delicate pale or colorless
threads, little branched, and smooth; spores violaceous-brown, minutely
roughened, 8-9 mu.
A very beautiful species occurring at the same time as the preceding and
in similar situations. All our specimens from the west are on dead
leaves of oak; some eastern gatherings are on moss. Easily recognized
when fresh by its delicate pink or roseate color; weathered specimens
are white, and might be confused with forms of _D. reticulatum_, but the
sporangia in the present species are less flattened and only rarely in
special situations run off to linear or plasmodiocarpous shapes
characteristic of _D. reticulatum_.
Not common, although widely distributed from east to west. New England,
New York, New Jersey, South Carolina, Ohio, Illinois, Iowa, Nebraska,
California (_Harkness_), Washington, Oregon.
8. DIDERMA NIVEUM (_Rostafinski_) _Macbr._
PLATE XVIII., Fig. 11 and 11 _a_
1875. _Chondrioderma niveum_ Rost, _Mon._, p. 170.
1877. _Diderma albescens_ Phillips, _Grev._, V., p. 114.
Sporangia gregarious, scattered, or more often crowded, sessile,
depressed-spherical, sometimes ellipsoidal or elongate, white, the outer
peridium crustaceous, chalky, smooth and fragile, the inner distinct,
delicate, ochraceous; hypothallus scant or none; columella well
developed, globose or hemispherical, orange-tinted or ochraceous;
capillitium abundant, made of threads of two sorts, some purplish or
dusky, with pale extremities, uneven, others more delicate and
colorless, and with wart-like thickenings, all sparingly branched;
spores violet-brown, minutely roughened, 9-10 mu.
This species is not common. From Colorado we have fine specimens typical
in every way. Specimens from Washington are flat so far as at present at
hand; probably represent _D. deplanatum_ (R.) List., which the last
named author regards as varietal of the present species, entering it and
_D. lyallii_ as sub-species 2 and 1 respectively. _D. deplanatum_ may
perhaps be best so disposed of; but _D. lyallii_ is distinguished at
sight, as well as by microscopic characters, spores nearly twice as
great, rougher and different in color.
9. DIDERMA CINEREUM _Morg._
1894. _Diderma cinereum_ Morg., _Myx. Mi. Val._, p. 70.
Sporangia gregarious, more or less crowded or even confluent,
sub-globose, only slightly depressed, ashen white; the peridium not
obviously double, very smooth and thin, rupturing irregularly;
hypothallus an indistinct membrane or wholly wanting; columella large,
globose or hemispheric, white, the surface granulose; capillitium of
very slender colored threads, the extremities pellucid, more or less
branched; spores violaceous, minutely warted, 9-11 mu.
Growing on old wood, leaves, etc. The sporangium .3-.5 mm., thin and
smooth or rugulose. This elegant little species I know only from
specimens received from Mr. Morgan. It seems to be closely related to
_D. spumarioides_, from which it is distinguished by its color, darker,
and its smoother, or less spinulose spores. The author compares the
color and external appearance to that of _P. cinereum_,--_Jour. Cin.
Soc._, XVI., p. 154.
Ohio, Pennsylvania.
10. DIDERMA HEMISPHERICUM (_Bull._) _Horne._
1791. _Reticularia hemispherica_ Bull., _Cham. de Fr._, I., p. 93.
1829. _Didymium hemisphericum_ (Bull.) Fr., _Syst. Myc._, III.,
p. 115.
1829. _Diderma hemisphericum_ (Bull.) Horne., _Fl. Dan._, XI., p. 18.
1832. _Didymium michelii_ Lib., _Pl. Ard._, No. 180.
1873. _Chondrioderma michelii_ (Lib.) Rost., Fuckel, _Sym. Myc._,
p. 74.
Sporangia gregarious, orbicular, discoid, depressed above and often
umbilicate below, stipitate or sometimes sessile, the outer peridium
white, fragile, crustaceous, soon breaking about the margins, closely
applied to the inner, which is delicate, cinereous, and ruptures
irregularly; stipe about equal to the diameter of the sporangium, 1 mm.,
rather stout, calcareous but colored, brownish or alutaceous, more or
less wrinkled longitudinally, the wrinkles when present forming veins on
the lower surface of the sporangium; hypothallus small; columella not
distinct from the thickened brownish or reddish base of the sporangium;
capillitium of delicate threads, mostly simple and colorless, often
scanty; spores pale violaceous, nearly smooth, 8-9 mu.
A very well marked species, easily recognized, at least when stipitate,
by its remarkable discoid or lenticular sporangia. After the
spore-dispersal, the stipes are long-persistent, surmounted by a
peculiar disk representing the consolidated columella, lower sporangial
wall, and expanded stem-top. Sessile specimens are like similar forms of
_D. reticulatum_, but in all the gatherings before us the stipitate type
is at hand to reveal the identity of the species.
Rostafinski's figures, 131, 146, 149, and 150, adapted from Corda,
exaggerate the hypothallus, but otherwise leave nothing to be desired.
As to synonymy, Bulliard has plainly the priority. His figure, t. 446,
Fig. 1, can refer to nothing else, especially reenforced as it is by
Sowerby, _Eng. Fung._, t. 12.
Rather rare on fallen stems of herbaceous plants, but widely
distributed, New England to Oregon and Washington.
11. DIDERMA SAUTERI (_Rost._) _Macbr._
1875. _Chondrioderma sauteri_ Rost., _Mon._, p. 181.
1891. _Chondrioderma aculeatum_ Rex, _Proc. Phil. Acad._, p. 390.
Sporangia scattered, gregarious, sessile, lenticular or hemispherical,
flattened above and sometimes concave or umbilicate below, dusky or
yellowish white, the outer peridium papyraceous, thin, occasionally
wrinkled, rupturing irregularly, remote from the inner, which is thin,
delicate, semi-transparent, grayish, rarely iridescent; hypothallus
none; columella irregular, sometimes small and hardly evident, rugose,
with spine-like processes, the persisting bases of the capillitial
threads, reddish brown; capillitium scanty, white, or colorless, simple
or sparingly branched; spores dark violaceous, spinulose, 12-13 mu.
This is _Chondrioderma aculeatum_ Rex, _Proc. Acad. Nat. Sci. Phil._,
1891, p. 390. After careful comparison of specimens and various
descriptions, especially that of Rostafinski with the type specimens of
Dr. Rex, I am constrained to concur with Lister in adopting
Rostafinski's name. The sporangia in the type specimens (Rex) are on
moss, borne at the extreme tips of acuminate or aculeate leaves, so that
at first sight they appear stipitate.
Apparently rare. Maine, New York.
12. DIDERMA COR-RUBRUM _Macbr. n. s._
PLATE XVIII., Fig. 2
Sporangia gregarious clustered, small .5-.7 mm., sessile
corrugate-plicate, especially above, snow-white, the outer peridium
cartilaginous polished without and within, the inner delicate,
evanescent; columella well developed, globose or clavate, anchored by
several stout transverse trabeculae to the peridial wall, papillate,
deep-red as is the peridium especially below; capillitium very delicate,
sparingly branching, colorless; spores verruculose, fuliginous tinged
with red, about 12 mu.
This curious but elegant little species is represented by a single
colony collected by Professor Morton Peck in Iowa. It resembles _D.
sauteri_ but is distinguished by the plicate white wall, the stout
columella with its lateral extensions, as by the more delicate spores.
On rotten wood.
13. DIDERMA OCHRACEUM _Hoffm._
1795. _Diderma ochraceum_ Hoffm., _Deutsch. Fl. Tab._ 9, 2, b.
1911. _Diderma ochraceum_ Hoffm., List., _Mycetozoa, 2nd ed._, p. 109.
Sporangia gregarious or clustered, .7-1 mm., sessile, globose or
sometimes plasmodiocarpous, ochraceous yellow; outer wall cartilaginous
with yellow deposits of lime, the inner also yellow, adherent or free;
columella not distinct; capillitium simple or branching, purple-brown,
hyaline at base; spores spinulose, purplish-grey, 9-11 mu.
Mr. Lister reports this species from Massachusetts.
14. DIDERMA ROANENSE (_Rex_) _Macbr._
1893. _Chondrioderma roanense_ Rex, _Proc. Phil. Acad._, p. 368.
Sporangia scattered, discoidal, thin, flattened or slightly convex
above, plane or plano-concave below, umber-brown, stipitate, the outer
peridium smooth, brittle, rupturing irregularly, the basal fragments
somewhat persistent, concrete with the inner peridium, which is pure
white, except near the columella, and punctate; stipe short, variable,
longitudinally ridged, jet-black; hypothallus none; columella flat,
discoidal, pale ochraceous; capillitium sparse, white or colorless,
composed of simple, rarely forked, sinuous threads occasionally joined
by lateral branches; spores dark violaceous, distinctly warted, 12-14 mu.
This species is readily distinguished by its color. The sporangia, found
on rotten wood, are large, 1 mm., brown, and have thick, persistent
walls. Dr. Rex considered that the species differs from other related
forms not only in color, but in the well-marked discoidal columella and
the jet-black irregular stipe. It is perhaps most nearly related to the
following species.
Tennessee.
15. DIDERMA RADIATUM (_Linn._) _Morg._
PLATE XVIII., Fig. 8
1753. _Lycoperdon radiatum_ Linn. (?) _Sp. Pl._, 1654.
1797. _Didymium stellare_ Schrad., _Nov. Gen. Pl._, p. 21.
1801. _Diderma stellare_ (Schrad.) Persoon, _Syn._, p. 164.
1875. _Chondrioderma radiatum_ (Linn.) Rost., _Mon._, p. 182.
1894. _Diderma radiatum_ (Linn.) Morg., _Jour. Cin. Soc._, p. 66.
1899. _Diderma stellare_ Schrad., Macbr., _N. A. S._, p 104.
1911. _Diderma radiatum_ List., _Mycetozoa, 2nd ed._, p. 112.
Sporangia scattered, depressed-globose, sometimes also flattened below,
stipitate, smooth or slightly corrugate, ashen or brownish, about 1 mm.
in diameter, the peridium dehiscing irregularly or somewhat radiately
from above downwards, the segments reflexed, the inner layer not
distinguishable, or inseparable; stipe short, stout, brownish, sometimes
almost lacking; hypothallus not conspicuous, but sometimes sufficient to
connect the bases of adjacent stipes; columella large, hemispherical or
globose, pallid or yellowish; capillitium abundant, of slender generally
simple, colored threads, paler at the furcate tips; spores dark
violaceous, minutely roughened, 8-11 mu.
Rare on rotten logs in the forests; September. Easily recognized by the
short-stiped, ashen sporangia which before dehiscence indicate by
delicate tracings the lines which subsequent cleavage is to follow. In
texture the peridium resembles that of _D. floriforme_.
Pennsylvania, Ohio, Iowa, Virginia, Colorado, Washington, Oregon; Europe
generally.
The Linnaean description on which to base the specific name _D. radiatum_
is wholly inadequate. It appears also by the testimony of Linne _fils_,
that _L. radiatum_ Linne is a lichen! and the name is so applied by
Persoon. But in the Linnaean herbarium preserved at London, _teste_
Lister, the original type of _Lycoperdon radiatum_ L. may yet be seen!
to the confusion of _fils_, Persoon, and other followers of Schrader
all, and our stellar species becomes radiate now, let us hope for long!
16. DIDERMA TREVELYANI (_Grev._) _Fr._
1825. _Leangium trevelyani_ Grev., _Scot., Cr. Fl._, Tab. 132.
1829. _Diderma trevelyani_ (Grev.) Fr., _Syst. Myc._, III., p. 105.
1875. _Chondrioderma trevelyani_ (Grev.) Rost., _Mon._, p. 182.
1877. _Diderma geasteroides_ Phill., _Grev._, V., p. 113.
1877. _Diderma laciniatum_ Phill., _Grev._, V., p. 113.
Sporangia scattered, globose or nearly so, smooth or verruculose,
reddish-brown or rufescent, sessile or short-stipitate, the outer
peridium firm, splitting more or less regularly into unequal, revolute,
petal-like lobes which are white within, the inner not distinguishable
as such; stipe, when present, equal, furrowed, concolorous; columella
small or none; capillitium abundant, the threads rather rigid, purple or
purplish brown, branching and anastomosing, more or less beaded; spores
dark, violaceous brown, spinulose, 10-13 mu.
In 1876, Harkness and Moore collected in the Sierra Nevada Mountains of
California, forms of _Diderma_ which are described by Phillips, _Grev._,
V., p. 113, as _D. geasteroides_ and _D. laciniatum_. English
authorities who have examined the material agree that the forms
described constitute but a single species, and Lister makes them
identical with _D. trevelyani_ (Grev.) Fr. Rostafinski's figures, 161,
162, are a curious reproduction, evidently, of Fried. Nees von
Esenbeck's, Plate IX., Fig. 4. Massee describes a columella; Lister
says there is none. What may occasion such divergence of statement none
may say; such forms as come in so far from our western mountains have no
columella.
17. DIDERMA ASTEROIDES _List._
PLATE XVIII., Figs. 3, 3 _a_
1902. _Diderma asteroides_ List., _Jour. Bot._, XL, p. 209.
1911. _Diderma asteroides_ List., _Mycetozoa, 2nd ed._, p. 113.
Sporangia globose or ovoid-globose, the apex more or less acuminate,
sessile, sometimes narrowed at the base to a short, thick stalk, brown
or chocolate tinted, marked at the apex by radiant lines, and at length
dehiscent by many reflexing lobes revealing the snow-white adherent
inner peridium on the exposed or upper side; columella also white,
globose or depressed-globose; capillitium generally colorless, somewhat
branched, especially above; spores dark violaceous, verruculose, 10-12
mu.
Oregon, the Three Sisters Mountains; Colorado; California.
A very beautiful species, recognizable at sight; when unopened, by the
peculiar chocolate brown, the sporangia smaller than in _D. radiatum_.
When opened, the snow-white flower-like figure, flat against the
substratum, is definitive. Very near number 16 preceding; the dehiscence
more regular.
18. DIDERMA FLORIFORME (_Bull._) _Pers._
PLATE VIII., Figs. 1, 1 _a_, 1 _b_.
1791. _Sphaerocarpus floriformis_ Bulliard, _Champ._, p. 142, t. 371.
1794. _Diderma floriforme_ (Bull.) Persoon, _Roem. N. Mag. Bot._,
p. 89.
Sporangia crowded, generally in dense colonies, globose, smooth,
ochraceous-white, stipitate, the peridium thick, cartilaginous,
splitting from above into several petal-like lobes, which become
speedily reflexed exposing the swarthy spore-mass, the inner peridium
not discoverable, inseparable; stipe concolorous, about equal to the
sporangium; hypothallus, generally well developed, but thin,
membranaceous, common to all the sporangia; columella prominent, globose
or cylindric, often constricted below, and prolonged upward almost to
the top of the spore-case; capillitium of slender, delicate, sparingly
branched threads; spores dark violaceous-brown, studded with scattered
warts, 10-11 mu.
Not uncommon, especially on rotten oak logs. Easily recognized by the
peculiar form of the fruit, spherical before dehiscence, floriform
after. Unlike most species, this form often fruits in dark places, in
the interior of a log, even in the ground.
New England, Ontario to Iowa and Nebraska, and south.
19. DIDERMA RUGOSUM (_Rex_) _Macbr._
PLATE XVIII., Fig. 10.
1893. _Chondrioderma rugosum_ Rex, _Proc. Phil. Acad._, p. 369.
Sporangia gregarious, scattered, white or ashen, rugulose over the whole
surface, the ridges marking the lines of subsequent rupture or
dehiscence, the peridium thin papyraceous, stipitate; stipe well
developed about equal to the sporangium, subulate, almost black;
hypothallus none; columella distinct, generally white, sometimes small,
globose, sometimes penetrating the sporangium, to one-half the height;
capillitium white or colorless, the filaments freely forked and combined
by lateral branches into a loose network attached to the columella and
basal wall below and the upper sporangial wall above; spores
violaceous-brown, warted, 8-10 mu.
This species is well designated _rugosum_, and is recognizable at sight
by its wrinkled, areolate surface. Related to _D. radiatum_ in the
prefigured dehiscence, but otherwise very distinct. Liable to be
overlooked as a prematurely dried physarum. Rare. Plasmodium gray.
North Carolina, Iowa.
=4. Lepidoderma= _DeBary_
1858. _Lepidoderma_ DeBy., MS. Rost., _Versuch_, p. 13.
Sporangia stalked or sessile; peridium cartilaginous, adorned without
with large calcareous scales, superficial or shut in lenticular
cavities; capillitium non-calcareous.[33]
=Key to Species of Lepidoderma=
_A._ Sporangia stipitate, stipe brown 1. _L. tigrinum_
_B._ Sporangia sessile, plasmodiocarpous,
spores 10-12 mu 2. _L. carestianum_
_C._ Sporangia plasmodiocarpous, spores 8-10 mu 3. _L. chailletii_
1. LEPIDODERMA TIGRINUM (_Schrad._) _Rost._
PLATE XIV., Fig. 7.
1797. _Didymium tigrinum_ Schrad., _Nov. Gen. Plantarum_, p. 22.
1873. _Lepidoderma tigrinum_ (Schrad.) Rost., _Versuch_, p. 13.
Sporangia scattered, rather large, hemispherical-depressed, stipitate,
umbilicate beneath, the peridium shining, olivaceous or purplish, tough,
covered more or less abundantly with angular scales; the stipe stout,
furrowed, dark brown, but containing calcareous deposits withal,
tapering upward, and continued within the peridium as a pronounced more
or less calcareous columella; hypothallus more or less prominent,
yellowish or brownish; capillitium dark, purplish-brown, of sparingly
branching threads radiating from the columella; spores dull
purplish-brown, minutely roughened, 10-12 mu.
A singular species, rare, but easily recognized by its peculiar, placoid
scales, large and firmly embedded in the peridial wall. The internal
structure is essentially that of _Diderma_ or _Didymium_. The species
occurs in hilly or mountainous regions, on moss-covered logs. The
plasmodium pale yellow, some part of it not infrequently remains as a
venulose hypothallus connecting such sporangia as are near together.
New England to Washington and Oregon; Vancouver Island.
2. LEPIDODERMA CARESTIANUM (_Rabenh._) _Rost._
1862. _Reticularia carestiana_ Rabenh., _MS. Fung. Eur. exsic._,
No. 436.
1875. _Lepidoderma carestianum_ (Rabenh.) Rost., _Mon._, p. 188.
1891. _Amaurochaete minor_ Sacc. & Ell., _Mich._, II., p. 566.
Fructification in the form of flat, pulvinate plasmodiocarps, or, anon,
sporangiate, the sporangia sessile, sub-globose, ellipsoidal, elongate,
irregular, confluent, yellowish-grey, the peridium covered more or less
completely with dull white, crystals or crystal-like scales; columella,
where visible, yellowish-brown, calcareous; capillitium, coarse, rigid,
more or less branched and united, or colorless, delicate, forming a
definite net; spores distinctly warted, purple 10-12 mu.
This is a most remarkable species. The sporangiate forms little resemble
those distinctly plasmodiocarpal. In the former the calcic scales and
crystals are distinct and quite as in _L. tigrinum_; in the latter they
are cuboid, irregular. The wall of the peridium in the plasmodiocarps at
hand is black, and the covering accordingly shows white; in the
sporangial forms the wall is brown, and the scales have a yellow tinge
as if tinged with iron. In the sporangial presentation the capillitium
is intricate delicate; in the plasmodiocarp, rigid, dark-colored, etc.
This looks like a didymium and in so far justifies the opinion of
earlier students. Fries, of course, includes all these things with the
didymiums, and _D. squamulosum_ probably often sheltered them under
extended wing.
_Didymium granuliferum_ Phill., _Grev._, V., p. 114, from California is
by European authors referred here. The capillitium carries calcareous
crystalline deposits in special vesicles and the spores show remarkable
variation in unusual size--15-30 mu.[1]
Should probably be entered _Lepidoderma granuliferum_ (Phill.) Fr.,
spores 15-18 mu.[34]
Utah,--Harkness.
3. LEPIDODERMA CHAILLETII _Rost._
PLATE XVIII., Figs. 6, 6 _a_, 6 _b_.
Sporangia distinct, coalescent or plasmodiocarpous, large, when isolated
1-1.5 mm., dull drab in color, very sparsely sprinkled with white
tetrahedral or irregular scales; the peridium thin, more or less
translucent, rugulose, dull brown, persistent; columella none;
capillitium abundant, under the lens purple-brown, sparingly branched,
even, stout, rigid, no calcareous deposits nor vesicles; spores 8-10 mu,
minutely warted, fuliginous.
Yosemite Canyon, California, _Prof. B. Shimek._
This is, no doubt, similar to _L. carestianum_ but differs in the size
and habit of the sporangia, and in the fact that the capillitium is
uniform throughout, whatever the style of fructification, and in the
size, color, and surface characters of the spore.
Evidently not _Didymium granuliferum_ Phill. Both will, no doubt, be
again collected, and we shall then have much needed light.
Nor is this quite Rostafinski's species as cited. The spores are much
smaller; Rostafinski says 10-12 or more, and calls for a distinctly
netted capillitium, the surface strongly marked by abundant calcareous
crystals. Ours may be a different thing.
=5. Colloderma= _G. Lister_
1910. _Colloderma, Jour. of Botany_, XLVIII., p. 312.
Peridium double; the outer gelatinous, the inner membranaceous;
capillitium intricate, limeless.
COLLODERMA OCULATUM (_Lipp._) _G. Lister._
1894. _Didymium oculatum_ Lipp., _Verh. Zo-Bot. Ges. Wien_, XLIV.,
p. 74.
1910. _Colloderma oculatum_ (Lipp.) G. List., _Jour. Bot._, XLVIII.,
p. 312.
Sporangia gregarious, globose, or sub-globose, sessile or
short-stipitate, olivaceous or purplish-brown, smooth and shining, the
outer peridium gelatinous, thickened by moisture, hyaline; stipe dark
brown; columella none; capillitium as in _Didymium_ purplish-brown,
colorless at the tips; spores spinulose, fuscous, about 12 mu.
New Hampshire, Europe.
Our specimens from the late Dr. W. G. Farlow who collected it in New
Hampshire. Swollen by immersion in water the sporangia take on an
eye-like appearance, oculate, etc.
=EXTRA-LIMITAL=
PHYSARINA _von Hoehnel._
1909. _Physarina_ von Hoehnel, _Akad. Wiss. Wien; Math-nat. KL._,
CXVIII., p. 431.
Sporangium wall rough with blunt spine-like processes, otherwise as
_Diderma_.
One species, _op. cit._, p. 432, _P. echinocephala_ v. Hoehn.
Java. Might as well be called _Diderma echinocephalum_, one would think.
Structure is that of _Leangium_. The striking character is a surface
modification of the outer peridium, according to the description.
ORDER II
=STEMONITALES=
Capillitium present, thread-like, arising in typical cases from a
well-developed columella; spores in mass, black or violet-brown, more
rarely ferruginous.
=Key to the Families of Stemonitales=
_A._ Fructification aethalioid, capillitium poorly
defined; columella rudimentary or none AMAUROCHAETACEAE
_B._ Fructification of distinct sporangia, capillitium
well defined; the columella generally prominent,
long and abundantly branched throughout STEMONITACEAE
_C._ Sporangia distinct; capillitium developed chiefly
or only, from the summit of the columella LAMPRODERMACEAE
_A._ AMAUROCHAETACEAE
Fructification aethalioid, an inch or two in diameter, in form varying
with the habitat and place; capillitium dendroid, consisting of rather
stout branches which rise irregularly more or less vertically from the
hypothallus, branch repeatedly, often anastomose to form a network,
especially toward the periphery; spores black.
A single genus--
=1. Amaurochaete= _Rostafinski_
1873. _Amaurochaete_ Rost., _Versuch._, p. 8.
The genus _Amaurochaete_ as defined by Rostafinski and the genus
_Reticularia_ as represented by _R. lycoperdon_ Bull. stand, the
expression, perhaps, of not dissimilar histories. Whether in regressive
or progressive series, each to-day presents a case of arrested
development. Each in aethalioid fructification, reveals a mass of
involved individual (?) sporangia, so imperfectly developed that their
outlines can be inferred rather than anywhere, with absolute
definiteness, certainly ascertained. Perhaps, because similar sporangia
in the group to which either belongs, do come under other circumstances,
to more perfect individual form and function--perhaps for this reason we
may look upon these aethalia as exhibiting a suspended performance; the
sporangia have failed to go forward to what was evidently a possible,
though apparently not an essential destiny in form and figure. For the
care and dispersal of the spores, achievement must surely be somewhat
impaired. Whatever the measure of such inefficiency, among the
_Stemonitales Amaurochaete_ shows the acme, as _Reticularia_ among the
brown-spored forms.
In _Amaurochaete_ the individuality of anything like separate sporangia
is less clear. The view afforded, however, by a good vertical section of
a well-developed colony or cushion is interestingly arborescent. Ragged,
dendroid stems arise, dissipated above into a network most intricate, a
"pleached arbor" if you please. The resemblance of the overhead net to
that presented by a stemonitis or comatricha is very striking.
=Key to the Species of Amaurochaete=
_A._ Capillitium rigid, irregular spores rough 1. _A. fuliginosa_
_B._ Capillitium soft, woolly, cincinnate,
spores as in _A_ 2. _A. tubulina_
1. AMAUROCHAETE FULIGINOSA (_Sowerby_) _Macbr._
PLATE V., Figs. 8, 8 _a_.
1803. _Lycoperdon fuliginosum_ Sow., _Eng. Fung._, t. 257.
1805. _Lycogala atrum_, Alb. & Schw., _Consp. Fung._, p. 83.
1875. _Amaurochaete atra_ (Alb. & Schw.) Rost., _Mon._, p. 211.
Fructification aethalioid, varying in form and size, if on the upper
side of the substratum, pulvinate, if below pendent and almost
stipitate, covered with a delicate cortex, at first shining, soon dull,
black, fragile, and early dissipated; hypothallus long-persisting,
supporting the capillitium, which is extremely variable, irregular, and
for its perfection dependent upon the form assumed by the aethalium, and
the conditions of weather, etc., under which it matures, sometimes,
especially when prostrate, in a very much depressed aethalium, spreading
into long fibrous threads, again under better conditions rising in
columella-like forms, supporting a peripheral net; spores dark brown or
black, irregularly globose, spinulose, 12.5-15 mu.
Common in Europe, and probably not uncommon in this country wherever
pine forests occur. Specimens before us are from New England and New
York, Ohio, Carolina, Colorado. Canada.
Sowerby, in his comment on plate 257, _Eng. Fungi_, says: "It appears to
consist of branching threads affixed to the deal and holding a dense
mass of sooty powder. Over the whole is a thin, deciduous pellicle."
This description seems to be applicable to nothing else. The figure
amounts to little. Fries recognizes the English description, as does
Rostafinski, but both authors adopt the later name given by Albertini
and Schweinitz, simply because of the excellent detailed description
found in the _Conspectus_.
2. AMAUROCHAETE TUBULINA (_Alb. & Schw._) _Macbr._
PLATE XX., 6 and 6 _a_.
1805. _Stemonitis tubulina_ (Alb. & Schw.), _Cons. Fung._, p. 102.
1825. _Lachnobolus cribrosus_ Fr., _Syst. Orb. Veg._, p. 14.
1912. _Amaurochaete cribrosa_ (Fr.) Macbr., _Com. in litt._
to Herbaria, Harvard, etc.[35]
1917. _Amaurochaete cribrosa_ (Fr.) Sturg., G. Lister, _Jour. Bot._,
LVIII, p. 109.
Plasmodium at first transparent then white then rosy, ashen or grey
finally deepening to jet-black; the aethalium even, thin, variable in
extent from one to ten centimeters, covered by a distinct but thin
transparent cortex, papillate, extended laterally but a short distance
beyond the fructification, fragile, soon disappearing; hypothallus
long-persistent, thin, silvery, supporting the capillitium as if by
stipes, short slender columns, irregular plates, expansions, etc.; the
capillitium an intricate network, very abundant, elastic, on fall of the
peridium appearing like tiny tufts of wool, the meshes large, but formed
as in _Stemonitis_, persistent, dull black; spores, under the lens, dull
olivaceous black, minutely roughened, 12-14 mu.
This species differs from the preceding, already well known, especially
in the capillitial characters. In the older species the capillitial
branches fray out, and are only sparingly united into a net extremely
lax. In the present form the net is the thing, common to all sporangia.
The total effect is to lend to the blown-out aethalium a woolly
appearance, entirely unlike that of its congener under the same
conditions. But until fructification is quite mature, the presence of
the collaborating sporangia below is indicated, suggested, by the
papillose upper surface.
The amaurochetes are remarkable in that they appear upon coniferous
wood, logs or lumber, to all appearance undecayed. The species just
described developed abundantly in August on the recently decorticated
logs of _Pinus ponderosa_, on the south-western slopes of Mt. Rainier,
Washington. In logging operations in the locality referred to, the trees
are felled often at considerable distance from the mill. They are not
infrequently large, 75-120 cm. in diameter. The logs are dragged along
the ground, the transportation facilitated by removal of the bark from
the new fallen trunk. In a few weeks' time, affected by alternate rain
and sun, the whole surface becomes marked with hundreds of minute,
almost invisible cracks, and it is in the larger of these that the
plasmodium of the present species has its habitat. Hardly any mycologic
phenomenon is more surprising than to see plasmodia rising to
fructification, scores at a time, upon a surface, new and white, showing
otherwise no evidence of any decomposition. Doubtless the persisting
cambium, the unused starches, sugars, the wood of the season yet
unlignified, afford easily accessible nutrition.
When this form was first examined in the laboratory its distinctness was
immediately seen. It was without doubt Fries' cribrose reticularia;
nobody questions that. Under this name, citing Fries' description,
specimens were sent out to herbaria as Harvard. Further study of the
records, however, soon convinces one familiar with the ontogeny of the
case that we are here face to face with the species, described by Alb. &
Schw. in their fine _Conspectus_. Their account of the form, evidently
often taken and now described with great care, is entirely clear when
read in presence of the facts. It is here submitted, as less easy of
access but essential, if the reader would appreciate the present
disposal of the species.
"S. Tubulina NOBIS
"_S. magna pulvinata subhemisphaerica, stylidiis gregariis
circinantibus, capillitiis elongatis cylindraceis in massam pulveraceam
fuscam connatis, apicibus obtusis, prominulis, lucidis nigris._
"The size indeed, the circumscribed form, the capillitiums conjoined
into a single body--indue this (form) with an appearance peculiar to a
degree; however, should anyone prefer to call it a very remarkable
variety of the preceding (_S. fasciculata_), we shall not strenuously
refuse. At first glance it looks like a tubulina. After the fashion of
its kind, the beginning is soft and milky. The diameter generally an
inch and a half to two inches, the height four to six lines; the form
perfectly round, or more rarely somewhat oblong. The hypothallus, stout,
pellucid silvery, betimes iridescent, when turned to the light, easily
separable from the substratum, bears the columellae, dusky, thin,
hair-like, aggregate and yet entirely free, and everywhere circinately
convergent, depressed by the superimposed burden, hence decumbent: ...
the capillitium loosely interwoven, coalesces to a common mass whose
smooth and shining surface shows above, regularly disposed minute
papillae, the apices of individual sporangia.
"Far from infrequent, on decorticate pine, of _Lycogala atrum_ a
constant companion"!
It goes of course without saying, that for the authors quoted, _Lycogala
atrum_ is _Amaurochaete atra_ Rost. _A. fuliginosa_ (Sow.) of more
recent students, described and perfectly figured in the volume cited.
It is surprising that they did not enter the present species also as a
lycogala. But the stemonitis relationship this time impressed them
rather than the aethalial; besides they were misled by the _S.
fasciculata_ of Gmelin and Persoon, a composite which the genius of
Fries hardly availed to disentangle twenty-five years later.
The last named author, as we see, wrote first _Lachnobolus_, then
_Reticularia_. He calls the interwoven capillitium--_lachne_, wool, a
"_pilam tactu eximie elasticam_," etc. He read the description in the
_Conspectus_, but carried away the stemonitis suggestion dominant there,
as we have seen, put _S. tubulina_ A. & S. as an undeveloped phase of
_S. fusca_, which, of course, it is not. It needed not the authority of
Rostafinski, _Mon._, p. 197, to assure us this. The earlier authors
describe the species in course of development to complete maturity, and
clinch the story by declaring the form a constant companion of the
commonly recognized amaurochete, so fixing the relationship for us by
habitat also.
These men made a mistake, of course, in placing their species among the
stemonites at all. They did much better however than Fries who called it
a reticularia. It was also a mistake to cite _S. fasciculata_,--the
small fasciculate tufts of _S. fusca_ and _S. axifera_ offering by the
aggregate habit only faint resemblance,--a possible refuge for those who
would prefer another disposition of their species distinct (_aliena_)
though it is.
Since Fries' day the species has been overlooked although the genus has
received more than once attention. Zukal _Hedwigia_, XXXV., p. 335,
describes _A. speciosa_ as a new species. This Saccardo writes down,
Syll. Fung., VII., p. 399, _S. tubulina_ A. & S., admitting, however, at
the same time, that as fine an authority as Raciborsky refuses to call
Zukal's species either a stemonite or an amaurochete, thinks it
deserving generic appellation of its own.
However, _A. speciosa_ Zuk. need not here concern us. Neither in his
description nor figures does Zukal at all approach the form we study.
His species is not an amaurochete; the size of the spores suggest that,
to say nothing of the capillitial structure.
In the same volume VII., the distinguished author introduces another
amaurochete, _A. minor_ Sacc. & Ellis, _Mich._ II., p. 566. This is
American; sent from Utah by our famous pioneer collector Harkness. A
specimen is before us: it is a lepidoderma! in shining, scaly armor
dressed; vid. under _L. carestianum_.
Since the distribution of Washington material, as mentioned, our species
reappears at various points in western Europe, points in England, etc.,
and will no doubt now share, hereafter as a century ago, the habitat so
long conceded to the long familiar older type.
_B._ STEMONITACEAE
Capillitium abundant, springing usually as dissipating branches from all
parts of the columella; the sporangia generally definite and distinct,
though sometimes closely placed and generally rising from a common
hypothallus.
=Key to the Genera of the Stemonitaceae=
_A._ Fructification aethalioid; capillitium charged
with vesicles 1. _Brefeldia_
_B._ Sporangia distinct, or nearly so.
_a._ Stipe and columella jet-black.
1. Capillitium so united as to form a surface
net 2. _Stemonitis_
2. Capillitial branch-tips free 3. _Comatricha_
_b._ Stipe and columella whitish; calcareous 4. _Diachaea_
=1. Brefeldia= _Rostafinski_
1873. _Brefeldia_ Rost., _Versuch_, p. 8.
Sporangia occupying in the aethalium several layers, those of the median,
and especially of the lowest layers, furnished with columellae which
blend beneath; capillitium threads in the lowest layers arising from the
columella, in the upper extending radiately between the individual
sporangia, and united at the sporangial limits by means of rather large
inflated sacs.
The genus _Brefeldia_ is, like some others, difficult to dispose of in
any scheme of classification where linear sequence must be followed.
Rostafinski placed it in an order by itself. Its relationships are on
the one hand with _Amaurochaete_ and _Reticularia_, and on the other
with the _Stemonitales_, though easily distinguished from either. It is
intermediate to _Amaurochaete_ and _Stemonitis_, and withal, as it
appears to us, a little nearer the latter, as the limits of the
individual sporangia are in _Brefeldia_ pretty well defined.
1. BREFELDIA MAXIMA (_Fr._) _Rost._
PLATE V., Figs. 7, 7 _a_, 7 _b_, and PLATES XXI., XXII.
1825. _Reticularia maxima_ Fries, _Syst. Orb. Veg._, I., p. 147.
1875. _Brefeldia maxima_ (Fr.) Rost., _Versuch._, p. 8.
Aethalium large, four to twenty cm, papillate above, violet-black at
first, then purple or purple-brown, developed upon a widespread,
silver-shining hypothallus; sporangia in favorable cases distinct,
indicated above by the papillae; columellae obscure, black; capillitium
abundant, the threads uniting by multifid ends to surround as with a net
the peculiar vesicles; spore-mass dark violet-black, the individual
spores paler by transmitted light, distinctly papillose, 12-15 mu.
A very remarkable species and one of the largest, rivalled by _Fuligo_
only. To be compared with _Reticularia_, which it resembles somewhat
externally, and with some of the larger specimens of _Enteridium_. The
plasmodium at first white with a bluish tinge is developed abundantly in
rotten wood, preferably a large oak stump, and changes color as maturity
comes on, much in the fashion of _Stemonitis splendens_, leaving a
widespread hypothallic film to extend far around the perfected
fruit-mass. In well-matured aethalia, "_Jove favente_," the sporangia
stand out perfectly distinct, particularly above and around the margins.
Closely and compactly crowded, they become prismatic by mutual pressure,
and attain sometimes the height of half an inch or more. In the centre
of the fructification, next the hypothallus, the sporangia are very
imperfectly differentiated. Many are here horizontally placed, and
perhaps supplied with an imperfectly formed peridium,--if so are to be
interpreted the lowest parts of the capillitial structure, the long,
branching, ribbon-like strands which lie along the hypothallus. Some of
these branch repeatedly with flat anastomosing branchlets, ultimately
fray out into lengthened threads, and perish after all the
superstructure has been blown away. From every part of the structure so
described, but more especially from the margins, are given off in
profusion the strange cystiferous threads, so characteristic of this
genus. These are exceeding delicate filaments, attached at one end, it
may be, to a principal branch, at the other free or united to a second
which again joins a third, and so looping and branching, dividing, they
form a more or less extended network, a capillitium in which are
entangled the myriad spores. Each filament bears at its middle point (or
is it the meeting point of two?) a peculiar plexus which embraces
several large cysts or vesicles whose function or further homology does
not readily appear.
From the base of the fructification rise also ascending branches which
are black, terete, and not infrequently branched as if to form the
capillitium of a stemonitis. These ascending branches are in many cases,
probably in all, real, though as yet imperfectly developed, columellae.
They rise, at least in many cases, directly from the hypothallus, each
is central to an individual sporangium, rises to about two-thirds its
height, but never attains the summit. The sporangia are so crowded that
many are choked off below, never reach the top of the aethalium. In such
cases the columella may cease at the sporangium-top. The columella bears
cystiferous threads sparingly, if at all; nevertheless these abound in
the peripheral portions of the sporangium all the way up, and are
especially noticeable beyond the level of the top of the columella. Many
are so arranged that the plexus with its vesicles occupies a place in
the plane separating adjacent sporangia, suggesting the possibility that
we have here to do with an imperfectly developed surface-net and
peridium. In this view the cysts would represent the meeting-point of
two opposite radial capillitial threads rather than the middle of one.
This accords with Rostafinski's observations and drawings. The cysts,
then, belong morphologically to the peridium or sporangium wall. It is a
stemonitis whose sporangia have never been perfectly differentiated, a
case of arrested development. See further under _Stemonitis confluens_.
Rostafinski really offers the first definitive description. Fries
probably distinguished it, but his description would not indicate the
fact except for the added note wherein appears the reason for discarding
an apparently older name, viz., that given by Link. But neither Link nor
Sowerby distinguished by description or figure _Brefeldia_ from
_Amaurochaete_.
Throughout the northern forest; Maine to Vancouver Island: not common.
=2. Stemonitis= (_Gleditsch_) _Rost._
1753. _Stemonitis_ Gleditsch, in part, _Meth. Fung._, p. 140.
1873. _Stemonitis_ (Gleditsch) Rost., _Versuch_, p. 7.
Sporangia distinct, though often closely aggregate, cylindric,
stipitate; columella prominent; capillitium well developed by repeated
lateral and apical branching of the columella, at length assuming at the
surface the form of a distinct net which supports an evanescent
peridium.
The genus is marked by its surface-net supported at the tips of the
dichotomously branched divisions of the columella. Over the net is
spread, theoretically at least, the peridial film supported by very
short points projecting from the net,--the peridial processes; the
peridium, however, is seldom seen; in some cases, certainly, is never
developed. Rostafinski first defined the genus as employed by recent
writers. Gleditsch simply renamed Micheli's _Clathroidastrum_; all
writers subsequent included species of other genera.
The taxonomy of this genus is of the most difficult. Macroscopic,
defining characters are few, and even these sometimes uncertain.
Microscopic distinctions also tend to be illusive, variable in such
fashion that often at the critical point the most exact description
fails. All that may be done at present is to recognize two or three
definite types and then cautiously differentiate among these with the
light we have, until more general study of the group brings to service a
wider range of observation with more comprehensive record on which
judgment may better be sustained.
We have before us many and beautiful forms of this genus yet unstudied.
Some of these doubtless have already found place in our growing
taxonomic literature; some apparently undescribed; all to wait wider
leisure or perhaps a younger hand.
The entire life-history of every form is none too much if we would set
out with any hope of accuracy the genetic relationships for which
taxonomy stands. Recently European students are making the color of the
plasmodium a basis for species-discrimination, which is good so far. But
plasmodic characters are at present unserviceable generally, for two
reasons; they vary in the same species; and unfortunately, when most
needed, they are unknown and inaccessible. The student is generally
confronted by forms mature, the plasmodic stage already past.
=Key to the Species of Stemonitis=
_A._ Sporangia connately united.
_a._ Spores verruculose 1. _S. confluens_
_b._ Spores reticulate 2. _S. trechispora_
_B._ Sporangia at maturity distinct.
_a._ Spore-mass grayish black.
1. Larger, 8-12 mm. spores distinctly
reticulate or warted, but sometimes
nearly smooth 3. _S. fusca_
2. Spores reticulate and spinulose.
i. Spores adherent, clustered 4. _S. uvifera_
ii. Sporangia very tall, 15-20 mm.,
rigid 5. _S. dictyospora_
iii. Sporangia short, jet- or
violet-black 6. _S. nigrescens_
_b._ Spore-mass rich brown.
1. Columella central.
i. Sporangia shorter, 5-6 mm., spores
banded 7. _S. virginiensis_
ii. Sporangia 8-10 mm.; spores
verruculose 8. _S. webberi_
iii. Sporangia tall, 15-20 mm. or more 9. _S. splendens_
2. Columella eccentric, sporangium in
cross-section, angular 10. _S. fenestrata_
_c._ Spore-mass ferruginous; sporangia in
tufts.
1. Spores smooth or nearly so.
i. Sporangia pale, small, 3-5 mm.,
crowded, stipe unpolished 11. _S. smithii_
ii. Sporangia ferruginous; columella
regular 12. _S. axifera_
iii. Sporangia ferruginous; columella
proliferate just below the apex 13. _S. flavogenita_
iv. Sporangia, spore-mass,
dusky-purplish or brown.
O On dead wood.
o Scattered, apex blunt 14. _S. pallida_
oo Clustered, acuminate 15. _S. carolinensis_
OO On living leaves, preferably,
spore-mass brown 16. _S. herbatica_
1. STEMONITIS CONFLUENS _Cooke & Ellis._
PLATE XI., Figs. 4, 4 _a_, 5.