The North American Slime-Moulds Part 25

Sporangia more or less distinctly cyathiform, stipitate, the peridium generally plainly of two layers or even of three, opening at the top by circ.u.mscission 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 circ.u.mscissile 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 circ.u.mscissile 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. cylindric.u.m_

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 circ.u.mscissile; stipe darker, one-half the height of the sporangium, longitudinally wrinkled; capillitium dense, abundantly calcareous; spores violet-brown, minutely roughened, 7-8 .

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 .

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."--_Ma.s.see._

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 circ.u.mscissile, 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-ma.s.s black, spores violaceous-brown, minutely spinulose, 8-9 .

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 ma.s.sed 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 CYLINDRIc.u.m _Ma.s.see_.

PLATE XVI., Fig. 2.

1873. _Craterium minimum_ Berk. & C., _Grev._, II., p. 67.

1892. _Craterium cylindric.u.m_ Ma.s.see, _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. _cylindric.u.m_ List., _Mycetozoa, 2nd ed._, p. 97.

Sporangia closely gregarious, very small, .5 or less, slender, cylindric, almost entirely white, stipitate, the peridium delicate, transparent although calcareous nearly to the base, opening by a dehiscence regularly circ.u.mscissile; 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-ma.s.s black, spores minutely roughened, violaceous-brown, 8-9 .

This is the common form in the United States. Ma.s.see describes it as _C.

cylindric.u.m_ Ma.s.s., 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.