The North American Slime-Moulds Part 44

PLATE VI., Figs. 1, 1 _a_, 1 _b_.

1772. _Mucor stemonitis_ Scopoli, _Fl. Carn._, II., pp. 493-494 (?).

1774. _Mucor stemonitis_ Schaeffer, _Icones. Tab._, CCXCVII (?).

1780. _Stemonitis typhina_ Wiggers, _Prim. Fl. Hols._, p. 116 (?).

1791. _Trichia typhoides_ Bulliard, _Champ. de la France_, p. 119, t. 477, II.

1796. _Stemonitis typhina_ Persoon, _Myc. Obs._, I., p. 57, in part.

1805. _Stemonitis typhoides_ (Bull.) D. C., _Fl. Fr._, p. 257.

1829. _Stemonitis typhoides_ (Bull.) Fr., _Syst. Myc._, III., p. 158.

1873. _Comatricha typhoides_ (Bull.) Rost., _Vers._, p. 7.

1875. _Comatricha typhina_ (Pers.) Rost., _Mon._, p. 197.

1895. _Comatricha stemonitis_ (Scop.) Sheldon, _Minn. Bot. Stud._, p. 473.

1899. _Comatricha stemonitis_ (Scop.) Sheld., Macbr., _N. A. S._, p. 130.

1911. _Comatricha typhoides_ Rost., List., _Mycetozoa, 2nd ed._, p. 157.

Sporangia gregarious, scattered, cylindric, erect, sometimes arcuate, obtuse, 2-3 mm. high, at first silvery, then brown, as the peridium vanishes, stipitate; stipe black, about one-half the total height or less; hypothallus distinct, more or less continuous, reddish-brown; columella tapering upward, black, attaining more or less completely the apex of the sporangium; capillitium, arising as rather stout branches of the capillitium, soon taking the form of slender, flexuous, brownish threads, which by repeated anastomosing form at length a close network, almost as in _Stemonitis_, the free, ultimate branches very delicate and short; spore-ma.s.s dark brown; spores by transmitted light, pale, almost smooth, except for the presence of a few scattered but very prominent umbo-like warts, of which four or five may be seen at one time, 5-7.5 .

This is our most common North American species. It occurs everywhere on decaying wood, sometimes in remarkable quant.i.ty, thousands of sporangia at a time. The plasmodium, watery white in color, infests preferably very rotten logs of _Quercus_, on which in June the sporangia rise as white or pallid columns. The peridium is exceedingly delicate, less seldom seen here than in some other species, but likely to be overlooked entirely. The spores when fresh have a distinct violet or bluish tinge; in old specimens they are almost colorless. In any case they are well marked by the large papillae already referred to.

_C. typhina_, var. _heterospora_ Rex, differs from the type in several particulars: the sporangia manifest a closer habit; the capillitium is made up of more slender threads and forms a yet denser network; the spores between the large papillae are marked by a more or less perfectly formed reticulation.[37]

As to nomenclature, this is our old friend _C. typhina_ (Pers.) Rost. It should be, more properly, called _C. typhina_ Rost., for it is not Persoon's species exactly. But Scopoli, _l. c._, by citing Hall, Gleditsch, and Micheli, so describes our form as to leave small doubt that he had before him our common species. Schaeffer's figures also come to the rescue, which, though by no means satisfactory, yet can probably refer to no other species. However, Bulliard gives the first good account and figure, and in concord with the decision of our English colleagues, the name afforded by the famous _Champignons_ is here adopted.

Widely distributed. Maine to California, and from British America to Nicaragua.

11. COMATRICHA ELEGANS (_Racib._) _List._

PLATE XVI., Fig. 12.

1884. _Rostafinskia elegans_ Racib., _Rozpr. Akad. Krak._, XII., 77.

1888. _Raciborskia elegans_ Berl., _Sacc. Syl._, VII., p. 400.

1894. _Raciborskia elegans_ Berl., List., _Mycet._, p. 133.

1909. _Comatricha elegans_ List., _Br. Mus. Guide to Mycet._, p. 31.

Sporangia loosely gregarious, globose, purplish-brown, small, 1-1.5 mm.

in total height, stipitate; stipe black, subulate, to 1 mm,; columella at first divided into a few main branches, from which by repeated subdivision the delicate, anastomosing, flexuose capillitial threads take origin; spores pale brownish-violaceous, spinulescent, 8-10 .

South Carolina. Colorado:--_Dr. Sturgis._

12. COMATRICHA RUBENS _Lister._

1894. _Comatricha rubens_ List., _Mycet._, p. 123.

Sporangia gregarious, globoid or ellipsoidal, 1-1.5 mm., pink-brown, stipitate; peridium persistent below; stipe .5-1 mm., black, s.h.i.+ning; columella to more than half the sporangium, giving off on all sides the brownish-violaceous, flexuose threads of the capillitium, somewhat thickened and broadly attached to the persisting peridial cup; spores lilac-brown, spinulescent, 7-8 .

Another border species, looking to the lamprodermas. Philadelphia, by courtesy _Mr. Bilgram_.

13. COMATRICHA PULCh.e.l.lA (_Bab._) _Rost._

PLATE XIII., Fig. 4, and PLATE XII., Figs. 16 and 16 _a_.

1837. _Stemonitis pulch.e.l.la_ Bab., _Trans. Lin. Soc._, p. 32.

1841. _Comatricha pulch.e.l.la_ Bab., Berk., _Ann. Mag. Nat. Hist._, I. vi., p. 431, Pl. XII., 11. _a._ _b._ 1848. _Stemonitis tenerrima_ Curtis, _Am. Jour._, VI., p. 352.

1873. _Stemonitis tenerrima_ Berk. & C., _Grev._, II., p. 69.

1876. _Comatricha pulch.e.l.la_ (Bab.) Rost., _Mon. App._, p. 27.

1875. _Comatricha persoonii_ Rost., _Mon._, p. 201.

1894. _Comatricha persoonii_ Rost., List., _Mycet._, p. 122.

1899. _Comatricha pulch.e.l.la_ (Bab.) Rost., Macbr., _N. A. S._, p. 129.

1899. _Comatricha persoonii_ Rost., Macbr., _N. A. S._, p. 132, _excl. syn._ 1911. _Comatricha pulch.e.l.la_ Rost., List., _Mycet., 2nd ed._, p. 156.

1911. _Comatricha pulch.e.l.la_ var. _gracilis_ Wing., List., _Mycet., 2nd ed._, p. 156.

Sporangia very minute, 1 mm. high, scattered, ovate or ovate-cylindric ac.u.minate, pale brown or ferruginous, stipitate; stipe short, black, nearly even; hypothallus none, or merely a circular base to the tiny stem; columella straight, gradually tapering, reaching almost if not quite to the apex of the sporangium; capillitium dense, a network of flexuous brown threads, rather broad within, ending in slender tips without; spore-ma.s.s brown, spores by transmitted light pale "lilac brown," or pale ferruginous, minutely but uniformly warted, 6-8 .

Probably widely distributed but rarely collected. Pennsylvania, Iowa; _Okoboji_. Toronto,--_Miss Currie._

14. COMATRICHA ELLISII _Morg._

PLATE XII., Figs. 15 and 15 _a_.

1894. _Comatricha ellisii_ Morg., _Jour. Cin. Soc._, p. 49.

1899. _Comatricha laxa_ Rost., Macbr., _N. A. S._, p. 127.

1911. _Comatricha nigra_ Schroet., List., _Mycet., 2nd ed._, p. 152.

Sporangia short, erect, oval or ovoid to oblong. Stipe and columella erect, brown and smooth, rising from a thin pallid hypothallus, tapering upward and vanis.h.i.+ng into the capillitium toward the apex of the sporangium, the stipe usually longer than the columella. Capillitium of slender pale brown threads; these branch several times with lateral anastomosing branchlets, forming a rather open network of small meshes, ending with very short free extremities. Spores globose, even, pale ochraceous, 6-7 mic. in diameter.

Growing on old pine wood. Sporangium .3-.6 mm. in height by .3-.5 mm. in width, the stipe usually a little longer than the sporangium.

On the strength of the clear descriptions and beautiful drawings of Celakowsky, _Myxomyceten Bohmens_, p. 52; Taf. 2, Figs. 7 and 8, this elegant little species as described by my colleague Professor Morgan was, in the former edition, referred to _C. laxa_ Rost. It was then reported from New Jersey only. Since then we have specimens from Ohio and from southern Missouri, all true to form, almost identical. It seems wise accordingly, while recognizing the relations.h.i.+p of the form to both _C. laxa_, and to _C. nigra_ as well, to give it here an individual place again. It is very small; but once studied may thereafter be easily recognized by a hand-lens. The form is definite, clean-cut, and the spores are p.r.o.nouncedly smaller than in either of the two related species.

15. COMATRICHA SUBCAESPITOSA _Peck._

PLATE XII., Figs. 17, 17 _a_.

1890. _Comatricha subcaespitosa_ Peck, _N. Y. Mus. Rep._ 43, p. 25.

Sporangia scattered or sometimes in loose cl.u.s.ters, cylindric, obtuse, about 1.5-2 mm., dark brown, stipitate; stipe short, one-fifth total height; hypothallus minute; capillitium regular, the branching quite uniform parallel, flexuous, brown with a tinge of violet, not dense; columella well-defined, almost percurrent; spores brown in ma.s.s, under lens dusky, nearly smooth, 9-10 .

The larger spores, regular, erect form, and cl.u.s.tered habit separate this form from others with which it will be naturally a.s.sociated. See page 283 under _Addenda_.

=4. Diachaea= _Fries_

1825. _Diachaea_ Fries, _Syst. Orb. Veg._, I., p. 143.[38]

Sporangia distinct, globose or cylindric, the peridium thin, iridescent, stipitate; the stipe and columella surcharged with lime, white or yellowish, rigid, thick, tapering upward; capillitium of delicate threads free from lime, radiating from various points on the columella, branching and anastomosing as in _Comatricha_ to form a more or less intricate network, the ultimate branchlets supporting the peridial wall.