The North American Slime-Moulds Part 42

i. Sporangia long, 10-12 mm. 4. _C. longa_

ii. Sporangia shorter, capillitium irregular 5. _C. irregularis_

_b._ Capillitium dense.

i. Sporangia large, to 10 mm., spore-ma.s.s black 7. _C. suksdorfii_

ii. Sporangia smaller--6 mm.

O Spore-ma.s.s brown, spherical, conoidal, etc., generally with more or less lengthened stipe 8. _C. nigra_

OO Spore-ma.s.s violaceous or purplish 9. _C. aequalis_

iii. Sporangia ovate or cylindric, minute, to 3.5 mm.

O Cylindric, spore with few, scattered warts 10. _C. typhoides_

OO Smaller, capillitium irregular, loose 6. _C. laxa_

OOO Total height to 2 mm. or much less.

+ Columella digitately divided 11. _C. elegans_

++ Columella lamprodermoid, and on leaves 12. _C. rubens_

+++ Columella stemonitoid 13. _C. pulch.e.l.la_

++++ Columella furcate at tip 14. _C. ellisii_

+++++ Columella almost percurrent. 15. _C. subcaespitosa_

1. COMATRICHA CaeSPITOSA _Sturgis._

PLATE XI., Figs. 12, 13, 14.

1893. _Comatricha caespitosa_ Sturg., _Bot. Gaz._, XVIII., p. 186.

1894. _Diachaea thomasii_ Rex, var., List., _Mycetozoa_, p. 92.

1899. _Comatricha caespitosa_ Sturg., Macbr., _N. A. S._, p. 124.

1911. _Diachaea caespitosa_ Lister, _Mycetozoa, 2nd ed._, p. 121.

Sporangia densely crowded or cespitose, sub-sessile or short stipitate, clavate, 1-1.5 mm. high, the peridium gray, iridescent with blue tints, comparatively permanent but finally disappearing; columella attaining two-thirds to three-fourths the height of the sporangium, giving rise throughout its length to the dense blackish capillitium; hypothallus delicate, inconspicuous; capillitium, the main branches thick at the point of origin, frequently anastomosing, and becoming gradually thinner toward the surface of the sporangium, the tips pointed, free, forming the network; spores blackish-violet in ma.s.s, by transmitted light pale brownish-violet, rough, 9.5-13 .

A very distinct and curious species. The sporangia are densely crowded, though by the nature of habitat somewhat tufted. The shape of the individual sporangium is quite uniformly clavate or obovate, decidedly truncate above. The spores are uniformly verruculose and plainly unequal.

This species, as indicated, was by its author described as a comatricha.

To transfer it to another genus seems idle, especially when long established generic boundaries must be seriously disturbed expressly to admit the new arrival.

New England, North Carolina, on moss and lichens.--_Dr. Sturgis._

2. COMATRICHA CYLINDRICA (_Bilgram_) _Macbr._

1905. _Diachaea cylindrica_ Bilgram, _Proc. Acad. Nat. Sci. Philad._, 524.

1911. _Diachaea cylindrica_ Bilgram, List., _Mycetozoa, 2nd ed._, p. 121.

Sporangia cylindrical with obtuse apex, sessile, gregarious, iridescent, steel-gray or bronze, 1 to 1.7 mm. high, .5 to .65 mm.

thick; hypothallus whitish, rugose; sporangium-wall membranous, hyaline, not adhering to the capillitium; columella arising from the hypothallus and extending nearly to the apex, brown, very light and semi-translucent near the base, irregular, flexuous, limeless throughout; capillitium brown, radiating from the columella to the periphery, repeatedly branching and anastomosing; spores warted, the warts connected by ridges forming a more or less perfect, coa.r.s.e reticulation, violaceous, pale, 10-12 .

This is a very interesting species closely related to the preceding from which it differs chiefly in the reticulation and generally more uniform character of the spores. The author hesitated about the generic reference, finally referring it to _Diachaea_ despite the lack of calcium, because it was sessile and had a peridium rather more persistent than is usual in comatrichas. But the presence of lime in stipe and columella is an essential element in the diagnosis of _Diachaea_, while length of stem is everywhere variable in stipitate forms of every genus, and the persistence of the peridium is also an uncertain factor; hangs on long in _C. typhoides_, _e. g._

On dead twigs, etc.--Philadelphia,--_Mr. Bilgram_; New Hamps.h.i.+re.

3. COMATRICHA FLACCIDA _List._

1894. _Comatricha flaccida_ List., Morg., _Jour. Cin. Soc._, p. 51.

1894. _Stemonitis splendens_, var. _flaccida_ List., _Mycetozoa_, p. 112.

1894. _Comatricha flaccida_ (List.) Morg., Macbr., _N. A. S._, p. 133.

1911. _Stemonitis splendens_, var. _flaccida_ List., _Mycetozoa, 2nd ed._, p. 146.

Sporangia semi-erect, close crowded in tufts two inches in diameter, ferruginous, from a dark brown hypothallus, sessile or short stipitate; columella weak, crooked, percurrent, generally enlarged irregularly at the apex; capillitium of few, slender, brown branches which anastomose spa.r.s.ely and irregularly as in _C. irregularis_, and present when freed from spores the same chenille-like appearance; spore-ma.s.s ferruginous brown; spores by transmitted light bright reddish brown, minutely warted, 8-10 .

"Growing on old wood and bark of Oak, Willow, etc. The component sporangia 5-10 mm. in length. The early appearance is much like that of a species of _Stemonitis_, but the mature stage is a great ma.s.s of spores with scanty capillitium, as in _Reticularia_; the columellas, however, are genuine and not adjacent portions of wall grown together."--_Professor Morgan._

Professor Morgan's herbarium material is at hand for study. It meets his description, needless to say, very generally. In what remains of the type the membranous connections are obscure; in fact the relation of such peridial (?) fragments to the capillitium in any way, is no longer evident. But in any event the colony does not impress one as something prematurely or improperly developed, a stemonitis gone begging;--nothing of that kind; it is clearly a comatricha, easily identifiable with no trace of a surface net but, with long free tips in plenty.

Misled no doubt, by the peridial fragments referred to, Mr. Lister in _Mycetozoa, l. c._, a.s.sociated this with _S. confluens_ Cke. & Ell., but entered it as a variety of _S. splendens_ Rost., just the same. In the second edition of the _Monograph_, Ellis' species is set out, but Morgan's retains the old position.

In light of present knowledge, the relations.h.i.+p suggested would be difficult of proof. If _C. flaccida_ Morgan be related to the _splendens_ group at all, it must be with the form known as _S. webberi_ Rex., but it differs from this in almost every particular. It has no net, with meshes uniform or diverse; it is clear brown in color, with a tinge of red, beneath the lens; the spores are smaller, distinctly warted and with the reddish tinge of the capillitium; and in short, it seems to be a comatricha and not a stemonitis.

Specimens from western Was.h.i.+ngton differ in some particulars but are apparently the same thing.

Ohio, Kentucky, Was.h.i.+ngton, California; not common.

4. COMATRICHA LONGA _Peck._

PLATE VI., Figs. 2, 2 _a_, 2 _b_.

1890. _Comatricha longa_ Peck, _Rep. N. Y. Mus._, XLIII., p. 24.

Sporangia crowded in depressed ma.s.ses or tufts, black, long, cylindric, even, stipitate; stipe black, s.h.i.+ning, generally very short; hypothallus well developed, black; columella black, slender, weak, generally dissipated some distance below the apex; capillitium of slender brown or dusky threads anastomosing to form an open network next the columella, but extended outwardly in form of long free slender branchlets, now and then dichotomously forked; spore-ma.s.s blue-black, spores by transmitted light dark brown, globose, spinulose, some of them faintly reticulate, about 9 .

A very remarkable species. Rare in the west, more common, as it appears, in the eastern states. The sporangia occur in tufts about 1 or 2 cm.

wide, springing generally from crevices in the bark of decaying logs, especially willow and elm, in swampy places. The sporangia are remarkable for their great length. Generally about 20-25 mm., specimens occasionally reach 50 mm.! The capillitial branches are so remote that the spores are scarcely retained by the capillitium at all. Well described and figured by the author of the species, _Forty-third Rep. N.

Y. State Museum_, p. 24, Pl. 3.

New York, Pennsylvania, Ohio, Iowa.