THE NORTH AMERICAN SLIME-MOULDS (continued 4)

The genus Comatricha was set off from Stemonitis by the joint effort of Preuss (1851) and Rostafinski (1873–5). Preuss included in his genus, Comatricha, alien forms, and besides failed to give an accurate definition; included, however, in his list some species which have since been known by his generic name.

The distinction between the two genera is almost an artificial one, and species are sometimes arbitrarily assigned to one genus or the other. The diagnosis in any case turns upon the presence or absence of a surface net, formed, in Stemonitis, by the anastomosing of the ultimate divisions of the capillitial branches. In Comatricha the anastomosing is general, from the columella out, and is not specialized at the surface.

Recent attempts to reunite the genera here compared seem to result in no apparent advantage. The genera come very near together, but their separation along the line suggested by Rostafinski remains convenient.

Key to the Species of Comatricha

A. Sporangia closely clustered.

a. Obovate or short cylindric.

1. Spores verruculose1. C. caespitosa

2. Spores reticulate2. C. cylindrica

b. Elongate, reddish-brown, tufts extended3. C. flaccida

B. Sporangia scattered more or less widely.

a. Capillitium lax, open.

i. Sporangia long, 10–12 mm.4. C. longa

ii. Sporangia shorter, capillitium irregular5. C. irregularis

b. Capillitium dense.

i. Sporangia large, to 10 mm., spore-mass black7. C. suksdorfii

ii. Sporangia smaller—6 mm.

O Spore-mass brown, spherical, conoidal, etc., generally with more or less lengthened stipe8. C. nigra

OO Spore-mass violaceous or purplish9. C. aequalis

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

O Cylindric, spore with few, scattered warts10. C. typhoides

OO Smaller, capillitium irregular, loose6. C. laxa

OOO Total height to 2 mm. or much less.

+ Columella digitately divided11. C. elegans

++ Columella lamprodermoid, and on leaves12. C. rubens

+++ Columella stemonitoid13. C. pulchella

++++ Columella furcate at tip14. C. ellisii

+++++ Columella almost percurrent.15. C. subcaespitosa

1. Comatricha cæspitosa 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 mass, by transmitted light pale brownish-violet, rough, 9.5–13 µ.

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, coarse reticulation, violaceous, pale, 10–12 µ.

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 Hampshire.

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 sparsely and irregularly as in C. irregularis, and present when freed from spores the same chenille-like appearance; spore-mass ferruginous brown; spores by transmitted light bright reddish brown, minutely warted, 8–10 µ.

"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 mass 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., associated 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 relationship 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 Washington differ in some particulars but are apparently the same thing.

Ohio, Kentucky, Washington, 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 masses or tufts, black, long, cylindric, even, stipitate; stipe black, shining, 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-mass blue-black, spores by transmitted light dark brown, globose, spinulose, some of them faintly reticulate, about 9 µ.

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.

5. Comatricha irregularis Rex.

1891. Comatricha irregularis Rex, Proc. Phil. Acad., p. 393.

Sporangia crowded in flocculent tufts, very dark brown or black, semi-erect or drooping, 4–5 mm. in height, irregularly cylindric, variable, stipitate; stipe black, distinct, often one-half the total height; hypothallus well developed, brown, shining; columella central, slender, flexuous, reaching the apex, where it blends, by branching, with the capillitium; capillitium loose, open, composed of arcuate threads which radiate from the columella, and are joined together, forming a central, irregular reticulation of large meshes, brown, paler toward the surface, where the free ends are sometimes colorless; spore-mass black, spores by transmitted light brown, minutely warted, 7–8 µ.

Related, no doubt, to C. longa, but differing in habit, stature, as in texture and structure of the capillitium. In C. longa the inner net is extremely simple,—a row or two of meshes at most, and the radiating branches are long and straight; in the species before us the inner network is well developed, and the radiating branches proportionately shorter and abundantly branching, with pale or white free tips.

Generally, though not always, found growing in the crevices of the bark on fallen logs of various deciduous trees. September. Not common.

This is thought to be C. crypta Schw., N. A. F., 2351; but the description under that number does not make clear what form Schweinitz had before him, the present species or C. longa, and the herbarium specimen of Schweinitz is "utterly lost"; the later specific name is accordingly adopted.

New England west to the Cascade Mountains; south to Kansas and Texas.

6. Comatricha laxa Rostafinski.

Plate V., Figs. 5, 5 a.

1875. Comatricha laxa Rost., Mon., p. 201.

1877. Lamproderma ellisiana Cooke, Myx. U. S., p. 397.

1891. Comatricha ellisiana (Cooke) Ell. & Ev., N. A. F., 2696.

Sporangia scattered, gregarious, sub-globose or short cylindric, and obtuse, dusky stipitate; stipe short, black, tapering rapidly upward from an expanded base; hypothallus scant or none; columella erect, rigid, sometimes reaching nearly to the apex of the sporangium, sometimes dichotomously branched a little below the summit, before blending into the common capillitium; capillitium lax, of slender, horizontal branches, anastomosing at infrequent intervals and ending in short, free tips; spores pallid, nearly smooth, 7–9.5 µ.

A very minute, delicate little species, about 1½ mm. high; the stipe half the total height. In general appearance the shorter forms of the species resemble slightly C. nigra, but are distinguished by a much shorter stipe and much more open capillitium. The sporangia of C. nigra mounted on long capillary stipes always droops more or less; the sporangia of the present species stand rigidly erect. The sporangia vary in form and in the branching of the columella. In the more globose phases, the columella almost always shows a peculiar dichotomy near the apex; in the cylindric types, this peculiar division fails.[36] In fact, the shape is determined chiefly by the mode of branching as affects the columella. Rostafinski's figure, on Tab. XIII, does not present the type usually seen in this country, nor even in Europe if we may judge from later illustrations.

The species with us has received various names, but so far as can be determined, all apply to the same thing, and comparison of specimens from Mr. Ellis with those from Europe show the correctness of the nomenclature here adopted.

Rare, but widely distributed; across the continent.

7. Stemonitis suksdorfii Ell. & Everh.

Plate XI., Figs. 9, 10, 11.

1882. Stemonitis suksdorfii Ell. & Everh., Bull. Washb. Coll., Vol. I., p. 5.

1892. Stemonitis suksdorfii Ell. & Everh., Mass., Mon., p. 76.

Sporangia scattered in small tufts or gregarious, cylindric, obtuse at both ends, sometimes widened above, black, 2–6 mm., stipitate; stipe jet-black, shining, even, about one-half the total height; hypothallus not continuous, dark brown; columella black, rather slender, terminating in two or more large branches just below the apex; capillitium exceedingly dense, dark fuscous or black, the flexuous threads anastomosing in a close network, with abundant free pallid extremities; spores in mass, blue-black, by transmitted light fuscous or dark violaceous-brown, minutely warted, 10–12 µ.

Easily recognizable at sight by its sooty color. Entirely unlike any of the preceding. The type of the capillitium is that of C. pulchella, but it is very much more dense and entirely different in color. The sporangia are often widened above, and fairly truncate; the total height about 6 mm. Found on the bark of fallen twigs of Abies, Larix, etc. Distributed by Ell. & Everh. under this name as an exsiccata. The evanescent peridium is colorless; when free, white or silvery.

8. Comatricha nigra (Pers.) Schroeter.

Plate XI., Figs. 1, 2, 3.

1791. Stemonitis nigra Pers., Gmel., Syst. Nat., p. 1467.

1801. Stemonitis ovata, var. nigra Pers., Syn., p. 189.

1863. Stemonitis friesiana DeBy., Rab. Eur. Fung., No. 568.

1875. Comatricha friesiana (DeBy.) Rost., Mon., p. 200.

1889. Comatricha nigra (Pers.) Schroeter, Pilz. Krypt. Fl. v. Schles., I., p. 118.

1894. Comatricha obtusata Fr., Lister, Mycetozoa, p. 117.

1899. Comatricha nigra (Pers.) Schroeter, Macbr., N. A. S., p. 128.

Sporangia scattered, ferruginous or dark brown, globose or ovoid, stipitate; stipe long, hair-like, tapering upward, black; hypothallus none; columella rapidly diminished toward the top, at length dissipated; capillitium of slender flexuous threads, radiating horizontally, repeatedly branching and anastomosing to form an intricate dense network, from the surface of which project a few short hook-like peridial processes; spore-mass black, spores by transmitted light dark violaceous, smooth or nearly so, 7–10 µ.

This species, when typical, is easily recognized by its almost globose sporangia mounted on long slender stocks. These are 2 or 3 mm. high and generally persist, as Persoon noticed, a long time after the sporangium has fallen. The sporangia are at first black; after spore disposal pale ferruginous. In shape they vary from ovate to spherical. Sometimes they are umbilicate below, so that a vertical section would be obcordate. Care must be taken to distinguish the present species from blown-out forms of Lamproderma.

This most common species seems to be also the center of widest differentiation. In a valuable paper on the Myxomycetes of Dr. C. H. Peck's Herbarium Dr. Sturgis points out the varying relationships of a group of surrounding forms. According to account C. nigra verges on one side to C. laxa, on the other to aequalis which the Listers enter as varietal here. However, in the former the more rigid, direct and simple branching from the columella is usually determinative; in the latter the color, form, and generally more delicate structure, and a tendency to grow in tufts will serve to distinguish.

In this discussion we have assumed as typical the globose sporangium, with the variations in the direction of ovate, obovate, ellipsoidal, etc., the capillitium flexuous and more richly anastomosing near the columella. On the drier slopes in the mountains of Colorado specimens are especially abundant, in proper season covering apparently the lower surface of every barkless twig or fallen stem or tree entire! In such a field one might imagine every possible variation open to observation. Probably such is the case; but as a matter of fact a single small plasmodium at lower levels will sometimes show greater range of variation than were noted on the mountain-side. The cylindric forms were for some reason few, and when noted were short, though often surmounting stems of double the usual length.

Rostafinski calls this C. friesiana, a name suggested by De Bary. By this name the species was commonly known for many years. More recently some writers prefer C. obtusata Preuss; but C. obtusata Preuss, as figured by that author (Sturm's Deutsch. Fl., Pl. 70), is surely more likely Enerthenema papillata, and the author says in his description "capillitio vertice soli innato." Persoon certainly recognized the species, and his description, though brief, is yet applicable to no other European species. There seems no reason why the name he gave should not be permanently adopted. Rostafinski's figure, Tab. XIII., shows an ellipsoidal sporangium, not cylindric.

On the lower levels of the Mississippi valley, the species is not common. Possibly overlooked by reason of its minuteness.

Massachusetts, Pennsylvania, Ohio, Iowa, Colorado, North Carolina, Missouri.

9. Comatricha æqualis Peck.

Plate VI., Figs. 3, 3 a, 3 b, 3 c, 3 d; and Plate XVIII., Figs. 13, 13 a, 13 b.

1890. Comatricha equalis Peck., Rep. N. Y. Mus., XXXI., p. 42.

Sporangia gregarious, seldom erect, usually inclined, curved or nodding, dark brown, becoming violet, cylindric, acuminate-obtuse, stipitate; stipe about half the total height, 2–2½ mm., black, polished, even; hypothallus well developed, brown, continuous; columella black, tapering gradually, and attaining almost the summit of the sporangium; capillitium dense, of flexuous tawny threads which, by repeated branching, form an intricate network, the free extremities numerous, short, and pale; spores dark violaceous, distinctly warted, 7.5–8 µ.

A very graceful, elegant species, related to C. pulchella and C. persoonii, but distinct by its much greater size and smaller spores. The specimens before show us the perfection of beauty in this genus; the polished stipe, the symmetrical capillitium, the soft purple-brown tints, are remarkable, and enable one to recognize the form at sight.

Specimens from Oregon are unusually fine; larger than usual, reach 7 mm. total height, and when blown out present the tints of violet in unusual clearness; var. C. pacifica. Plate XVIII., Figs. 13, 13a, and 13b.

New York, Pennsylvania, Ohio, Illinois; Oregon, Professor Peck.

10. Comatricha typhoides (Bull.) Rost.

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-mass 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 µ.

This is our most common North American species. It occurs everywhere on decaying wood, sometimes in remarkable quantity, 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 papillæ 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 papillæ 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 µ.

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, shining; 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 µ.

Another border species, looking to the lamprodermas. Philadelphia, by courtesy Mr. Bilgram.

13. Comatricha pulchella (Bab.) Rost.

Plate XIII., Fig. 4, and Plate XII., Figs. 16 and 16 a.

1837. Stemonitis pulchella Bab., Trans. Lin. Soc., p. 32.

1841. Comatricha pulchella 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 pulchella (Bab.) Rost., Mon. App., p. 27.

1875. Comatricha persoonii Rost., Mon., p. 201.

1894. Comatricha persoonii Rost., List., Mycet., p. 122.

1899. Comatricha pulchella (Bab.) Rost., Macbr., N. A. S., p. 129.

1899. Comatricha persoonii Rost., Macbr., N. A. S., p. 132, excl. syn.

1911. Comatricha pulchella Rost., List., Mycet., 2nd ed., p. 156.

1911. Comatricha pulchella var. gracilis Wing., List., Mycet., 2nd ed., p. 156.

Sporangia very minute, 1 mm. high, scattered, ovate or ovate-cylindric acuminate, 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-mass brown, spores by transmitted light pale "lilac brown," or pale ferruginous, minutely but uniformly warted, 6–8 µ.

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 vanishing 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 Böhmens, 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 relationship 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 pronouncedly 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 clusters, 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 mass, under lens dusky, nearly smooth, 9–10 µ.

The larger spores, regular, erect form, and clustered habit separate this form from others with which it will be naturally associated. See page 283 under Addenda.

4. Diachæa 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.

Rostafinski placed this genus near the Didymieae on account of the calcareous columella and the non-calcareous capillitium. On the other hand the structure of the capillitium and the iridescent simple peridium ally Diachaea to Lamproderma and the Stemoniteae; the only distinction being the calcareous stem. It is simply an intermediate genus to be placed here more conveniently than anywhere else in what is of necessity a linear arrangement.

Key to the Species of Diachæa

A. Stipe and columella white.

a. Sporangium cylindric1. D. leucopodia

b. Sporangium globose.

i. Evidently stalked2. D. splendens

ii. Stalk very short, 5 mm., conic.

O Spores warted3. D. bulbillosa

OO Spores faintly netted4. D. subsessilis

B. Stipe yellowish or orange5. D. thomasii

1. Diachaea leucopodia (Bull.) Rost.

1791. Trichia leucopodia Bull., Champ. de la France, Pl. 502, Fig. 2.

1825. Diachaea elegans Fries, Syst. Orb. Veg., I., p. 143.

1875. Diachaea leucopoda (Bull.) Rost., Mon., p. 190.

Sporangia rather closely gregarious, metallic blue or purple iridescent, cylindric or ellipsoidal, obtuse, sub-umbilicate below, stipitate; stipe short, much less than one-half the total height, snow-white, tapering upward; hypothallus white, venulose, occurring from stipe to stipe to form an open network over the substratum; columella thick, cylindric, tapering, blunt, terminating below the apex, white; capillitium springing from every part of the columella, of slender threads, brown, flexuous, branching and anastomosing to form an intricate net; spores in mass nearly black, by transmitted light dull violaceous, minutely roughened, 7–9 µ.

A very beautiful species; not uncommon in the eastern states; rare west of the Mississippi. Easily recognized, amid related forms, by its snow-white stem, a feature which did not escape the notice of Bulliard and suggested the accepted specific name. Fries adopted the specific name proposed by Trentepohl and wrote D. elegans, simply because to him the peridium was "admodum elegans."

The peridium is exceedingly thin and early deciduous; the stipe long persistent. The plasmodium, dull white, was observed by Fries at the beginning of the century; "morphoseos clavem inter myxogastres hoc genus primum mihi subministravit."

This species, as the diachæas generally, affects fallen sticks and leaves in orchards and forests and even spreads boldly over the foliage and stems of living plants.

New England, New York, Pennsylvania, Maryland, Virginia, South Carolina, Ohio, Iowa, California, Canada.

2. Diachaea splendens Peck.

Plate VII., Figs. 1, 1 a, 1 b, 1 c.

1877. Diachaea splendens Peck, Rep. N. Y. Mus., XXX., p. 50.

Sporangia gregarious, metallic blue with brilliant iridescence, globose, stipitate; stipe white, short, tapering upward; hypothallus white, venulose, a network supporting the snowy stipes; columella white, cylindric, passing the centre, obtuse; capillitium lax, of slender, anastomosing, brown, translucent threads; spores in mass black, by transmitted light dark-violaceous, very coarsely warted, 7–10 µ.

This is perhaps the most showy species of the list. The globose brilliantly iridescent sporangia are lifted above the substratum on snow-white columnar stalks; these are again joined one to another by the pure white vein-like cords of the reticulate hypothallus. The plasmodium may spread very widely over all sorts of objects that come in the way, dry forest leaves and sticks, or the fruit and foliage of living plants. Closely resembling the preceding, but differing in the globose sporangia, it may be instantly recognized under the lenses by its coarsely papillate spores.

Not common. New York, Pennsylvania, Ontario, Ohio, Iowa, Nebraska.

3. Diachaea subsessilis Pk.

1879. Diachaea subsessilis Pk., Rep. N. Y. Mus. Nat. History, XXXI., p. 41.

1894. Diachaea subsessilis Pk., Lister, Mycetozoa, p. 92.

Sporangia gregarious or closely crowded, small, about .5 mm., dull iridescent-blue, greenish-gray, etc., globose or depressed-globose, short-stalked or nearly sessile; stipe generally very short, reduced sometimes to a mere persistent cone, white; columella obsolescent or reduced to white conical intrusion of the stipe; capillitium radiating from the stipe, brown, consisting of branching, anastomosing threads, paler at the tips; hypothallus very scanty or none; spores minutely warted, the papillæ arranged in an irregular, loose net-work, violet-brown, paler under the lens, 10–12 µ.

This species is easily recognizable by its diminutive size and generally defective structure; i. e. it has the appearance of a degenerate or depauperate representative of some finer form. Besides the type, yet to be seen in Albany, Dr. Sturgis reports the species from Connecticut and from the Isle of Wight! A small gathering is before me from Colorado. Every sporangium is borne upon a calcareous pedicel, very short indeed, but real. The var. globosa referred to in the English text under D. leucopodia has not appeared so far as reported, on this side the sea, but even such variety could scarcely in the hands of a collector take the place of the form now under consideration.

Specimens of D. subsessilis from Europe correspond remarkably with those described by Drs. Peck and Sturgis. Mr. Lister would have our species a synonym for Lamproderma fuckelianum cracovense (Rost.) Cel.

Rare; from Connecticut to Colorado.

4. Diachæa bulbillosa (Berk. & Br.) List.

1873. Didymium bulbillosum Berk. & Br., Jour. Linn. Soc., XIV., p. 84.

1898. Diachaea bulbillosa Lister, Jour. Bot., XXXVI., p. 165.

1911. Diachaea bulbillosa Lister, Mycetozoa, 2nd ed., p. 119.

Sporangia gregarious, globose, small, iridescent purple, stipitate; stipe conical, white, sometimes brown, half-a-mm., half the total height; columella clavate, white or brown; capillitium of purple-brown threads united to form a lax net; spores violet-grey, marked with scattered warts "6–8 in a row across the hemisphere", 7–9 µ.

Java, Berkeley & Broome, op. c. Toronto, Canada; cited here by courtesy of Miss Currie who gives the spores 7.8 µ.

5. Diachaea thomasii Rex.

Plate V., Fig. 6, 6 a.

1892. Diachaea thomasii Rex, Proc. Phil. Acad., p. 329.

Sporangia gregarious, more or less crowded, purple and bronze, iridescent, globose sessile or short stipitate; stipe, when present, very short, thick, tapering rapidly upward, orange; hypothallus orange, prominent venulose, continuous; columella ochre yellow, rough, cylindric, tapering upward to one-half the height of the sporangium, obtuse; capillitium lax, of slender brown rigid threads, radiating from the columella in every direction, anastomosing to form a loose, large-meshed network; spore-mass brown; spores by transmitted light violaceous, minutely, unevenly warted, 10–12 µ.

The peculiar orange color of the calcareous deposits in stipe and columella easily distinguish this species. The capillitium is also distinctive, rigid, simple, and comparatively scant, lamprodermoid. Rex calls attention to the fact that under low magnification the spores appear spotted; but the spots are occasioned simply by the closer aggregation, at particular points, of the ordinary papillæ.

A southern species. All the specimens so far reported are from the mountains of North Carolina.

The specimens referred to under this name by Lister, Mon., p. 92, as coming from "Kittery, U. S. A." (Kittery, Maine?), are, no doubt, according to Mr. Lister's figures, Comatricha caespitosa Sturgis. See under that species.

C. LAMPRODERMACEÆ

Sporangia distinct, generally gregarious, more or less spherical; capillitium developed chiefly or solely from the summit of the columella.

Key to the Genera of the Lamprodermaceæ

A. Columella percurrent; capillitium from a disk at the apex1. Enerthenema

B. Columella scarce reaching the centre of the sporangium.

a. Capillitium not forming a net2. Clastoderma

b. Capillitium forming an intricate net3. Lamproderma

c. Minute, capillitium rudimentary4. Echinostelium

1. Enerthenema Bowman

1828. Enerthenema Bowman, Trans. Linn. Soc., XVI., p. 152.

Sporangia stipitate, the stipe extended as a columella, which entirely traverses the sporangium and forms at the apex an expanded disk; from this depends the capillitium.

Key to the Species of Enerthenema

A. Spores free1. E. papillatum

B. Spores in clusters2. E. berkeleyanum

1. Enerthenema papillatum (Pers.) Rost.

Plate V., Fig. 3.

1801. Stemonitis papillata Pers., Syn., p. 188.

1828. Enerthenema elegans Bowm., Trans. Linn. Soc., XVI., p. 152.

1862. Comatricha obtusata Preuss, Sturm, Deutschl. Flora, Pl. LXX.

1876. Enerthenema papillatum (Pers.) Rost., Mon. App., p. 28.

Sporangia scattered or crowded, stipitate, spheroidal, naked, black fuscous, above, shining, adorned with a minute, black papilla; stipe black, opaque, conical or attenuate upward, about equal to the peridium; columella at the apex expanded into a shining disk; capillitium springing from the lower side of the disk or from its edge, made up of scarcely forked threads which are free below; spores violaceous or fuscous black, minutely warted, 10–12 µ.

Rare. Wisconsin, Ohio, South Carolina, Illinois, Pennsylvania, Iowa, Colorado.

This is one of the few species so well marked that Persoon's description, l. c., is definitive: "Stylidio toto penetrante. Capillitium exacte globosum, sub-compactum, in eius apice stylidium papillæ in modum prominet." For this reason Bowman's specific name elegans is discarded.

2. Enerthenema berkeleyanum Rost.

1876. Enerthenema berkeleyanum Rost., Mon. App., p. 29.

1913. Enerthenema syncarpon Sturgis, Myxo. Col., II., p. 448.

This species corresponds to the preceding in all respects except in the fact that the spores are clustered in groups of four to twelve and are a little larger, 11–13 µ, strongly spinulose on the exposed surface.

Dr. Sturgis reports this from Colorado, l. c., but discards Rostafinski's specific name on the ground that the type has disappeared; only the spores of some fungus hyphæ remain in the place and these may have been mistaken by Berkeley. This seems hardly possible since such supposition would not account for the generic reference either by Berkeley (and Broome) or by Rostafinski. The description in the Monograph is minute as that of one who had the form under his lenses. Rostafinski saw Berkeley's specimens.

For a similar case, see under Prototrichia metallica, Mycetozoa 2nd ed., p. 261.

South Carolina, type; Colorado.

2. Clastoderma Blytt

1880. Clastoderma Blytt, Bot. Zeit., XXXVIII., p. 343.

Sporangium globose, distinct, stipitate; the columella short or obsolete; the capillitium of few sparsely branched threads, which bear at their tops the persistent fragments of the peridium, but are not otherwise united.

Distinguished from Lamproderma by the peculiar manner in which the peridium is ruptured, and by the simplicity of the scanty capillitium. So far there appears to be but a single species.

1. Clastoderma debaryanum Blytt.

Plate XIII., Fig. 6, and Plate XVI., Fig. 13.

1880. Clastoderma debaryanum Blytt, Bot. Zeit., XXXVIII., p. 343.

1886. Orthotrichia microcephala Wing., Jour. Myc., II., p. 126.

Sporangia scattered or gregarious, very minute, 1-12 to ¼ mm. in diameter, the peridium fugacious, except the minute patches that adhere to the capillitial branchlets, and the slight annulus at the base of the columella; stipe long, unequal, dark below, above paler; columella almost none, giving early rise to the comparatively few slender threads which by their repeated forking make up the capillitium; spores globose, even, violaceous, 8–9 µ.

Reported in the United States so far from Maine, Pennsylvania, Ohio, and Illinois.

The sporangia are very small, but beautiful, delicate little structures, found on the bark of living red oak in this country; in Norway it seems to have been seen first on a dead polyporus. Its minuteness doubtless causes it to be generally overlooked, N. A. F., 2498.

3. Lamproderma Rostafinski

1873. Lamproderma Rostafinski, Versuch, p. 7.

Sporangia stipitate, globose, or ellipsoid; columella cylindric or inflated or clavate at the apex, scarcely attaining half the height of the peridium; peridium shining with metallic tints, deciduous, except where, at the base of the columella, it forms a ring around the stipe; capillitium rising in tufts or by simple branches from the columella, the threads regularly forked, generally united into a net.

The lamprodermas are distinguished from the comatrichas, to which they are most nearly allied, by the arrangement of the capillitium, its development from the apex only of the columella, the continuation of the stipe within the peridium. In other words, the peridium leaves the stipe some distance below the point where the lowest capillitial branches take origin. In mature specimens the peridium has often entirely disappeared, its only trace, a collar, more or less distinct, around the stipe, marking the beginning of the columella. Nevertheless the peridium is far more persistent than in any comatricha, and shows in yet greater brilliancy the wondrous metallic tints and iridescence of Comatricha and Diachaea. Older authors, so far as can be seen, distributed the species between Physarum and Stemonitis.

Key to the Species of Lamproderma

A. Peridium metallic blue.

a. Stipe short, stout.

1. Capillitium tips colorless5. L. violaceum

b. Stipe long, slender.

1. Capillitium of dark, tapering, oft-united threads3. L. columbinum

2. Capillitial threads rigid, dark brown, seldom united4. L. scintillans

B. Peridium not blue, silvery.

a. Stipe long, slender.

1. Capillitium very intricate, forming a compact net6. L. arcyrionema

2. Capillitium of rigid dark brown threads1. L. physaroides

b. Stipe short, heads large, 1 mm. or more2. L. robustum

1. Lamproderma physaroides (Alb. & Schw.) Rost.

1805. Physarum physaroides Alb. & Schw., Consp. Fung., p, 103.

1875. Lamproderma physaroides (Alb. & Schw.) Rost., Mon., p. 202.

Sporangia gregarious, wide-spreading, globose, the peridium persistent with a silver metallic, sometimes brassy, lustre; stipe long, brown or black, tapering upward; hypothallus well developed, brown or purple, usually not continuous; columella swollen, obtuse, short at best, hardly attaining the centre of the sporangium; capillitium very rigid, of simple or sparingly branched, dark-brown threads radiating from the clavate apex of the columella and only here and there anastomosing toward the surface, the ultimate divisions distinctly rough; spores lilac brown, rough, 10–12.5 µ.

This species is well described and illustrated in Rostafinski's Monograph. It is well marked by its clavate columella and peculiarly simple, dark rigid capillitium, the branches of which rise in great numbers immediately from the columella, and maintain their primitive thickness during the greater part of their length. The transverse vincula are often at right angles to the principal branches, and the meshes, where formed, are often long and rectangular. Externally, it resembles L. arcyrionema, but is by its spores and capillitium instantly distinguished. Rostafinski gives the spores 12.5–14.2 µ. Large spores are less common in the specimens before us. Lister figures a sessile variety.

In our first edition this species was entered from lists published for New England, New York, and Ohio. The intervening years, however, have brought no confirmation. Specimens from Maine and Ohio, with large spores, represent L. columbinum, and those cited for New York are forms of L. violaceum. It is accordingly doubtful that L. physaroides (A. & S.) Rost. occurs in North America. That it is to be found in Europe there seems no doubt. The figure and description by Schweinitz, l. c., may indeed be inconclusive, but Rostafinski's citation and abundant description leave no doubt as to his opinion; while numerous localities named would indicate adequate material. What Rostafinski described will no doubt obtain wider recognition some day.

2. Lamproderma robustum Ell. & Evh.

1892. Lamproderma robustum Ell. & Evh., Mass., Mon., p. 99.

1894. Lamproderma violaceum var. sauteri Rost., List., Mycetozoa, p. 129.

1899. Lamproderma sauteri Rost., Macbr., N. A. S., p. 140.

Sporangia gregarious, globose, dull black, the peridium when present silvery, shining, or simply smooth, transparent and without iridescence, stipitate; stipe short, black, tapering rapidly upward, annulate with the persisting base of the peridium; columella short, thick, truncate, and widened at the top; hypothallus well developed, brown or purple; capillitium dense, made up of dark brown branches, numerous and rather slender, repeatedly branched and anastomosing toward the surface to form a slight delicate network with abundant free ends; spores dark purple brown, rough, 14–16 µ.

This species in outward appearance resembles L. physaroides, from which it is easily distinguished by the much greater diameter of the globose sporangium, 1 mm. or more. The persistent base of the peridium is also characteristic, very prominent sometimes, and visible to the naked eye. The capillitium is also unlike that of L. physaroides; resembles more nearly that of L. violaceum. From the latter species L. robustum is distinguished by the color of the peridium, and by the larger, darker spores and generally different capillitium. In our former edition this is called L. sauteri Rost. That much-quoted author distinguished L. violaceum and L. sauteri; the English authors make the last named a variety only of the former. This our American species is not.

It is, as presented in our western mountains, clear-cut, well defined, not a variety of anything. The original name is therefore restored.

Lamproderma arcyrioides (Somm.) Morgan is probably a form of L. columbinum. The original L. arcyrioides has not yet been certainly identified in North America; see following species.

Colorado, Oregon, Washington, California.

3. Lamproderma columbinum (Pers.) Rost.

1796. Physarum columbinum Pers., Obs. Myc., I., p. 5.

1875. Lamproderma columbinum Rost., Mon., p. 203.

Sporangia scattered, gregarious; rich violet or purple with metallic iridescence, globose, stipitate; the stipe long, three-fourths the total height, slender, subulate, black; hypothallus scant, purplish or brown; columella small, one-third the height or less, tapering or acute, black; the capillitium brown throughout, not dense, arising from nearly all parts of the columella, freely branching and anastomosing to an open, large-meshed network; spore-mass black, spores by transmitted light dark brown, rough, 10–12 µ.

Rostafinski distinguished this beautiful species by the color of the peridium and the conic columella. According to Mr. Lister, Rostafinski was not specially careful in labelling his material, different forms having been included under this specific name. Nevertheless, the description is well drawn, and excludes L. physaroides completely. At all events our American specimens correspond so well with the description of L. columbinum (Pers.) Rost. that there seems no doubt that we have here what the Polish author figured and described, whether or not he was always consistent in applying his labels. The color distinguishes at sight the present species from L. physaroides, and the capillitium and large rough brown spores distinguish it from L. violaceum. The capillitium of the minute L. scintillans is much denser and more rigid, and the spores smaller. The stipe when dry is ciliate.

This is the common species of our western mountains, especially on the Pacific slope. In the Cascades every dark ravine is certain to show it in later summer and autumn, far extended colonies covering the moist surfaces of every mouldering log; the myriad globoid sporangia giving back when brought to the sunlight the most extravagant blues and greens with all the splendor of metallic sheen, their brilliant beauty never fails to quicken the attention of even the most insensate tourist.

Abundant in the western forests, in the east extremely rare; Maine, Pennsylvania, South Carolina, Washington, Oregon; Vancouver, Canada.

4. Lamproderma scintillans (Berk. & Br.) Morg.

Plate V., Figs. 2, 2 a.

1877. Stemonitis scintillans Berk. & Br., Jour. Linn. Soc., XV., p. 2.

1877. Lamproderma arcyrioides, var. iridea Cke., Myx. G. B., p. 50.

1892. Lamproderma irideum (Cke.) Mass., Mon., p. 95.

1894. Lamproderma scintillans (Berk. & Br.) Morg., Jour. Cin. Soc., p. 47.

Sporangia gregarious, scattered, globose or depressed-globose, rich metallic blue or purple, iridescent, stipitate; the stipe long, slender, even, inclined and nodding or sometimes erect; hypothallus small, circular; columella cylindric, small, not reaching the centre, black; capillitium dense, of rigid, straight, sparingly branched or anastomosing, brown threads, which are sometimes white or colorless just as they leave the columella; spores globose, rough, violaceous brown, 8 µ.

This is L. irideum of Cooke and of Massee's Monograph. Its capillitium is remarkable, and constitutes an easy diagnostic mark. The threads appear at first sight entirely simple, but are really several times furcate, and not infrequently anastomose. The spores are covered with sparsely sown large papillæ, easily seen under moderate magnification.

This is one of our earliest species. To be sought in May on beds of decaying oak leaves in the woods, especially in wet places, near streams, etc.

Rare. New England, Pennsylvania, Ohio, Iowa.

5. Lamproderma violaceum (Fries) Rost.

1829. Stemonitis violacea Fries, Syst. Myc., III., p. 162.

1875. Lamproderma violaceum (Fries) Rost., Mon., p. 204.

Sporangia closely gregarious or scattered, depressed-globose, more or less umbilicate below, metallic blue or purple, sessile or short stipitate; stipe stout, dark brown or black, even; hypothallus, when the sporangia are crowded, a thin, continuous, purplish membrane; when the sporangia are scattered, the hypothallus discoidal; columella cylindric or tapering slightly upward, the apex obtuse, black, attaining the centre of the sporangium; capillitium lax and flaccid, made up of flexuous threads branching and anastomosing to form a network, open in the interior, more dense without, the threads at first pale brown as they leave the columella, becoming paler outward to the colorless tips; spores minutely warted, violaceous gray, 9–11 µ.

This is our most common species; found on decaying sticks and logs late in the fall. Its pale capillitium will usually distinguish it, especially where the sporangia are empty; then the pallid free extremities of the capillitial branches give to the little spheres under the lens a white or hoary appearance not seen in any other species.

The plasmodium is at first almost transparent, then amber tinted, sending up tiny semi-transparent spheres on shining brownish stalks. As the changes approach maturity, the sporangia become jet-black, and only at last when the spores are ready for dispersal does the peridium assume its rich metallic purple tints. Colonies a meter in length, two or three decimeters in width, are sometimes seen!

New England, New York, Pennsylvania, Ohio, Indiana, Illinois, Iowa, South Dakota; Toronto. Common.

6. Lamproderma arcyrionema Rost.

Plate V., Figs. 1, 1 a.

1875. Lamproderma arcyrionema Rost., Mon., p. 208.

Sporangia gregarious, scattered, globose, silvery gray or bronze, iridescent, erect, stipitate; stipe black, long, two-thirds to three-fourths the total height, slender, rigid; columella slender, cylindric, attaining about one-third the height of the sporangium when it breaks into the primary branches of the capillitium; capillitium exceedingly intricate, made up of slender, flexuous brown threads which frequently branch and anastomose to form an elegant round-meshed network resembling that of Arcyria, free ultimate branchlets not numerous; spores in mass jet-black, by transmitted light violaceous, smooth, or only faintly warted, 6–8 µ.

In outward appearance this species resembles L. physaroides, but is easily recognizable by its very peculiar capillitium. This, in its primary branching, resembles a comatricha. In typical forms, the columella branches at the apex only, generally into two strong divisions which then break up irregularly and anastomose in every direction. This seems to have been the form present to Rostafinski when he wrote "columella truncate." In Central American and some North American specimens, the branching is very different; the twigs leave the columella at various points almost down to the annulus, and the entire effect is dendroid. The columella is lost almost at once. A small form of this species was formerly distributed in the United States as Comatricha friesiana DeBy. This circumstance led the present author to describe Central American forms as C. shimekiana. Judging from a remark by Massee (Mon., p. 97), a similar confusion seems to have prevailed in Europe. As a matter of fact, the resemblance between C. friesiana, i. e. C. nigra, and the present species is sufficiently remote.

Lamproderma minutum Rostafinski seems to be a small form of this species. Rostafinski bases his diagnosis upon the branching of the columella, which is, as we have seen, inconstant, and upon the colorless capillitium. This feature in specimens examined is also inconstant.

Occurring in large colonies on barkless decaying logs of various species; the plasmodium almost colorless.

New England, Pennsylvania, Ohio, Louisiana, Texas, Mexico, Nicaragua; Vancouver's Island; Ontario, Toronto,—Miss Currie.

4. Echinostelium DeBary

1873. Echinostelium DeBary, Rost., Versuch, p. 7.

Sporangia distinct, globose, minute, the structure limited to a few imperfect rib-like, loosely joined branches developed from the short columella or stem-top, sustaining the spores.

A single species:—

1. Echinostelium minutum DeBy.

1873. Echinostelium minutum DeBy., Rost., Versuch, p. 7.

Plate XIX., Figs. 11 and 11 a

Sporangia distinct, scattered, globose, very minute, 40–50 µ, stipitate; the stipe, hair-like subulate, granular but hyaline; columella minute or none; capillitium consisting of a few arcuate spinose threads loosely united supporting the uncovered spores, spores globose, colorless, smooth, 7–8 µ.—Rostafinski.

This very singular and diminutive form, the least of all slime-moulds, is probably widely distributed but the accident of discovery is rare. DeBary found it once only, at Frankfurt am Main.

Miss Lister reports its occurrence in England and Austria. In the United States it has been seen but once on certain laboratory material from Massachusetts, studied by Dr. Thaxter.

Our drawing is after Rostafinski, IV., 68; Miss Lister follows No. 54, and so finds a bit of peridium below the two spores shown in the figure, one on each side of a microscopic columella.

This is almost the only taxonomic suggestion;—a mere suggestion; this microscopic bit of anxious life is but a shadow,—a shade, a shadow of a lamproderma!

Order III

CRIBRARIALES

Fructification plasmodiocarpous or æthalioid, or consisting of distinct sporangia; peridia membranaceous at maturity, more or less evanescent, opening irregularly or by means of a delicate network, which involves at least the upper part of the sporangium; capillitium usually none; spores of some shade of brown, umbrine, rarely purplish.

This order is distinguished—except in a single case—by the entire absence of true capillitium, the pallid or brown spores, the gradual evolution of distinct sporangia in which provision for spore-dispersal is made by peridial modification especially at the sporangium-top.

Key to the Families of the Cribrariales

A. Fructification plasmodiocarpous scattered as if made up of the segments of the plasmodial netLiceacæ

B. Fructification of distinct and separate sporangia, long stipitate, opening by a delicate operculum at the topOrcadellaceæ

C. Fructification æthalioid, the sporangia generally more or less tubular, often prismatic by mutual pressure; opening by rupture of the apex, the lateral walls entire Tubiferaceæ

D. Fructification æthalioid, the sporangia ill defined, their walls more or less perforate, frayed, or dissipated, forming a pseudo-capillitium,Reticulariaceæ

E. Fructification of distinct and separate sporangia, the walls more or less reticulately perforate especially aboveCribrariaceæ

A. LICEACEÆ

A single genus,—

1. Licea (Schrader) Rost.

1797. Licea Schrader, Nov. Gen. Plant., p. 16, in part.

1875. Licea (Schrader) Rost., Mon., p. 218.

Sporangia plasmodiocarpous, looped, irregular, or distinct, sessile, and regularly rounded or elliptical; the peridium simple, rather firm, ruptured irregularly or by simple fissure; hypothallus none.

This genus is distinguished from other similar plasmodiocarpous forms by the extreme simplicity of its structure. There is absolutely no capillitium nor anything like it, simply a mass of spores surrounded by thin membranous walls. The spores range from pale olive, colorless under the lens, through various shades of brown to dusky almost black in L. pusilla. Schrader included the Tubifera species.

Key to the Species of Licea

A. Plainly plasmodiocarpous1. L. variabilis

B. Opening by regular segments.

1. Segments two only2. L. biforis

2. Segments several.

i. Spores brown3. L. minima

ii. Spores dusky olive4. L. pusilla

1. Licea variabilis Schrader.

Plate XII., Figs. 7 and 8.

1797. Licea variabilis Schrader, Nov. Gen., p. 18, Pl. VI., Figs. 5 and 6.

1801. Licea variabilis Schr., Pers., Syn. Meth., p. 197.

1801. Licea flexuosa Pers., Syn. Meth., p. 197.

1911. Licea flexuosa Pers., List., Mycetozoa, 2nd ed., p. 189.

Fructification plasmodiocarpous, elongate, hamate, annulate or irregularly repent, very dark brown, rough, the peridium of two layers, the outer closely adhering, dark brown, thick, opaque, the inner delicate, membranous, very thin, transparent, iridescent, rugulose, rupturing irregularly; hypothallus none; spores in mass pale yellow with a greenish tinge, by transmitted light nearly colorless, large, globose, minutely spinulose, 12.5 µ.

This is the largest species of the genus as represented in this country, the plasmodiocarps of various lengths and from .5–.7 µ wide. Somewhat resembling some species of Ophiotheca, but of much darker color. The outer peridium is deciduous, and the inner slowly ruptures, by irregular fissures discharging the spores. The plasmodium, according to Schrader, is white. Rare. Probably overlooked.

Any good reason for changing the name given to this form so well illustrated and described by Schrader does not appear. Persoon quotes his predecessor's species and adds L. flexuosa on his own account; strangely enough, since Schrader expressly describes L. variabilis, "in uno eodemque enim loco peridium hemisphericum, ovatum, oblongum flexuosum vel aliter formatum diversi est diametri."

New York, Pennsylvania, Ohio, Iowa.

Licea flexuosa Pers. is by Schweinitz reported from Pennsylvania. It is described as having brown spores, 10–15 µ, spinulose.

2. Licea biforis Morgan.

Plate XII., Fig. 10.

1893. Licea biforis Morgan, Jour. Cin. Soc., p. 5.

Sporangia regular, compressed, sessile on a narrow base, gregarious; the wall firm, thin, smooth, yellow brown in color and nearly opaque, with minute, scattered granules on the inner surface, at maturity opening into two equal parts, which remain persistent by the base; spores yellow-brown in mass, globose or oval, even, 9–12 u.

Minute but perfectly regular, almost uniform, corneous-looking sporangia are thickly strewn over the inner surface of decaying bark. Each, at first elongate, pointed at each end, opens at length by fissure along the upper side setting free the minute yellowish spores. Unlike anything else; reminding one, at first sight, of some species of Glonium.

Inside bark of Liriodendron. Ohio, Canada.

3. Licea minima Fries.

1829. Licea minima Fries, Syst. Myc., III., p. 199.

Sporangia gregarious, umber-brown, spherical or hemispherical, sessile; the peridium opaque, brown, opening along prefigured lines, forming segments with dotted margins, ultimately widely reflexed; spores in mass dark brown, by transmitted light paler with olive tints, minutely roughened, 10–11 µ.

The very minute sporangia, 3 mm., of this species cause it to be overlooked generally by collectors. Nevertheless, it may be found on decaying soft woods, in August, probably around the world. The number of sporangia produced by one plasmodium is in Iowa also small. The larger specimens might be mistaken for species of Perichaena, but are easily distinguished by the regular and lobate dehiscence. The plasmodium is yellow.

Dr. George Rex, in almost the last paper from his hand, gives an interesting account of this diminutive species. Among various gatherings studied he found a black variety, a melanistic phase, so to say, and was able to follow the evolution of the sporangia from the yellow plasmodium. The sutures by which the peridium opens, first show signs of differentiation by change of color from yellow through garnet to black. Later the entire wall undergoes similar color changes, beginning next the completed sutural delimitations. Of the open peridia, the reflexed segments remind one of certain didermas, as D. radiatum. See Bot. Gaz., Vol. XIX., p. 399.

New England, New York, Pennsylvania, Iowa.

4. Licea pusilla Schrader.

1797. Licea pusilla Schrad., Nov. Gen. Pl., p. 19, tab. VI., f. 4.

1829. Physarum licea Fries, Syst. Myc., III., p. 143.

1875. Protoderma pusilla (Schrader) Rost., Mon., p 90.

Sporangia scattered, gregarious, depressed-globose, sessile on a flattened base, dark brown, shining, .5–1 mm.; peridium thin, dark colored, translucent, dehiscent above by regular segments; spore-mass almost black, spores by transmitted light olivaceous brown, smooth, or nearly so, 15–17 µ.

Fries, l. c., makes this a physarum, and argues the case at length, evidently with such efficiency that he greatly impressed Rostafinski, who did not make it a physarum indeed, but actually gave it generic place and station of its own; a physarum may do without calcium in the capillitium perhaps, but not be entirely non-calcareous; so he writes Protoderma (first cover) and places the species number 1 on the long list of endosporous forms. Even in his 'Dodatek', or supplement, as we should say, he refers to the thing again, but only to correct the inflexional ending of the specific name; he writes Protoderma pusillum (Schrader) Rost!

Schweinitz reports the species for America and Morgan cites Schweinitz and reports it for Ohio, but we find it in no American collections.

B. ORCADELLACEÆ;

Sporangia distinct, minute, long stipitate, opening above by a distinct lid.

A single genus,—

Orcadella Wingate

1889. Orcadella Wingate, Proc. Phil. Acad., p. 280.

Sporangia furnished with rigid, unpolished stipes, blending above with the substance of the thick unpolished walls; the operculum thin, delicate, membranaceous.

A single species,—

1. Orcadella operculata Wingate.

Plate XII., Fig. 11.

1889. Orcadella operculata Wingate, Proc. Phil. Acad., p. 280.

Sporangia scattered, gregarious, ellipsoidal, ovoid, obconical or nearly globose, dull brown or blackish, the wall simple, thick, coarse, at the top replaced by a delicate, thin, yellowish, iridescent, lustrous or vernicose membrane which forms a circular, smooth, or wrinkled lid, soon deciduous; stipe of varying height, rough from deposit of plasmodic refuse; spores, in mass yellowish, globose, smooth, 8–11 µ.

This curious little species, well described by its discoverer, appears to be very rare. At least it is seldom collected; overlooked by reason of its minuteness. It is a stipitate licea, or a lid-covered cribraria; perhaps nearer the former. It affects the bark of species of Quercus, and seems to be associated there with Clastoderma debaryanum. N. A. F., 2497.

Pennsylvania, Maine.

C. TUBIFERACEÆ

Fructification æthalioid or of distinct sporangia; sporangia well defined, tubular, often prismatic by mutual pressure, seated on a common, well-marked hypothallus, at length dehiscent by the irregular rupture of the peridium, in typical cases at the apex, its walls remaining then otherwise entire; capillitial threads in No. 3, only.

Key to the Genera of the Tubiferaceæ

A. Spores olivaceous; sporangia in one or several series,1. Lindbladia

B. Spores umber; sporangia in a single series2. Tubifera

C. Sporangia stipitate; capillitium of tubular threads3. Alwisia

1. Lindbladia Fries

1849. Lindbladia Fries, Sum. Veg. Scand., p. 449.

Fructification æthalioid; the sporangia short, tubular, sometimes superimposed, sometimes forming a simple stratum, in the latter case generally sessile, but sometimes short-stipitate, the peridium at first entire, at length opening irregularly either at the sides or apex, beset with granules; spores olivaceous.

This genus was established by Fries in 1849 to accommodate a single species of wide distribution and somewhat varying habit, which is neither a tubifera nor yet a cribraria and offers points of resemblance to each. It is distinct in that the sporangia, while often in single series, are yet often superimposed. It resembles Tubifera in its simple sporangia, opening without the aid of a net; it is like Cribraria in the smooth ochraceous-olivaceous spores and granuliferous peridium.

1. Lindbladia effusa (Ehr.) Rost.

Plate I., Figs. 3, 3 a, Plate XII., Figs. 1, 2.

1818. Licea effusa Ehr., Sylv. Myc. Ber., p. 26.

1875. Lindbladia effusa (Ehr.) Rost., Mon., p. 223.

1879. Perichaena caespitosa Peck, Rep. N. Y. Mus., XXXI., p. 57.

Sporangia minute, either closely combined and superimposed, so as to form a pulvinate æthalium, or crowded together in a single layer, sessile, or short-stipitate; the peridia thin, membranous, marked by scattered plasmodic granules, often lustrous, sometimes dull lead-colored or blackish, especially above; stipe, when present, very short but distinct, brown, rugulose; hypothallus well developed, membranous, or more or less spongiose in structure; spore-mass ochraceous, under the lens, nearly smooth, almost colorless, 6–7.5 µ.

This very variable species has been well studied by Dr. Rex. See Bot. Gaz., XVII., p. 201. In its simpler phases it presents but a single layer of sporangia generally closely crowded together, sometimes free and even short stipitate! In the more complex phase the sporangia are heaped together in a pulvinate mass in which the peridia appear as boundaries of minute cells. In this case the outermost sporangia are often consolidated to form a cortex more or less dense and shining. In any case the hypothallus is a prominent feature; generally laminated and of two or three layers, it is in the more hemispheric æthalia very much more complex, sponge-like. When thin this structure is remarkable for its wide extent, 40–50 cm.! The simpler forms approach very near to Cribraria through C. argillacea. The most complex remind us of Enteridium.

This is Perichaena caespitosa Peck. In this country it has, however, been generally distributed as L. effusa Ehr. This author throws some doubt on the species he describes by suggesting that the plasmodium may be red. The description, however, and figures are otherwise good and are established by the usage of Rostafinski. The plasmodium has much the same color as the mature fruit.

Widely distributed. New England to the Black Hills and Colorado, south to Arkansas. California, about Monterey.

2. Tubifera Gmelin

1791. Tubifera Gmelin, Syst. Nat., II., p. 1472.

Sporangia tubular, by mutual pressure more or less prismatic, connate, pale ferruginous-brown, iridescent, the walls thin, slightly granular, long-persistent; dehiscence apical; hypothallus thick, spongiose, white or whitish; spore-mass ferruginous.

This genus is easily recognized by the tubular sporangia, destitute of capillitial threads, seated upon a strongly developed hypothallus. The synonymy of the case is somewhat difficult. It is possible that Mueller's Tubulifera ceratum, Fl. Dan., Ellevte Haefte, 1775, p. 8, may belong here, but neither the text nor the figures make it certain. Neither he nor Œder, who gives us T. cremor in the same work, had any accurate idea of the objects described. Gmelin's description of Tubifera, II., 2, 1472, is, however, ample, and his citations of Bulliard's plates leave no doubt as to the forms he included. Gmelin writes: "Thecæ (membranæ expansæ superimpositæ) inter se connatæ seminibus nudiusculis repletæ."

Why, in face of so good a description, Persoon changed the name to that since current, Tubulina, is not clear.

Fries thinks Mueller had an immature Arcyria before him, Syst. Myc., III., p. 196. Tubulifera arachnoidea Jacq., 1778, is also an uncertain quantity, insufficiently described.

Key to the Species of Tubifera

A. Hypothallus well developed, but not conspicuous.

a. Pseudo-columellæ none1. T. ferruginosa

b. Pseudo-columellæ present at least in many of the tubules2. T. casparyi

B. Hypothallus prominent, columnar3. T. stipitata

1. Tubifera ferruginosa (Batsch) Macbr.

Plate I., Fig. 4; Plate VII., Fig. 8; Plate XII., Fig. 14.

1786. Stemonitis ferruginosa Batsch, Elench., p. 261, Fig. 175.

1791. Sphaerocarpus cylindricus Bull., Champ., p. 140, t. 470, III.

1791. Tubifera ferruginosa Gmelin, Syst. Nat., 1472 (ex parte).

1805. Tubulina cylindrica (Bull.) DC., Fl. Fr., 671.

1875. Tubulina cylindrica (Bull.) Rost., Mon., p. 220.

1894. Tubulina fragiformis (Pers.) Lister, Mycetozoa, p. 153.

Sporangia crowded, cylindric or prismatic, elongate, connate, more or less distinct above, pale umber-brown, generally simple though occasionally branched above, the peridia thin, sometimes fragile, but generally persistent, transparent, iridescent; hypothallus strongly developed, spongiose, white, often projecting beyond the æthalioid mass of sporangia; spore-mass umber-brown or ferruginous; spores by transmitted light almost colorless, plainly reticulate over three-fourths of the surface, 6–7 µ.

Not rare on old logs, mosses, etc., from Maine to Alaska. Apparently more common north than south. Easily known by its long, tubular sporangia packed with rusty spores and destitute of any trace of columella or capillitium, the hypothallus explanate, rather thick, but not columnar. A single plasmodium may give rise to one or several colonies, at first watery or white, then red, of somewhat varying shades, then finally umber-brown. These colors were noticed by all the older authors, but very inaccurately; thus a white plasmodium is the basis for Tubifera cylindrica (Bull.) Gmel., a roseate plasmodium for Tubifera fragiformis (Bull.) Gmel., and the mature fructification for Tubifera ferruginosa (Batsch) Gmel. Rostafinski adopted a specific name given by Bulliard, but Batsch has clear priority.

The peridia are sometimes accuminate, and widely separate above. This is Persoon's T. fragiformis. In most cases, however, the peridia are connate throughout, and sometimes present above a membranous common covering. This is T. fallax of Persoon; Licea cylindrica (Bull.) Fries. In forms with thicker peridia, the walls often show the granular markings characteristic of the entire Anemeae.

2. Tubifera stipitata (Berk. & Rav.) Macbr.

1858. Licea stipitata Berk. & Rav., Am. Acad., IV., p. 125.[39]

1868. Licea stipitata Berk. & Rav., Jour. Linn. Soc., X., p. 350.

1875. Tubulina stipitata (Berk. & Rav.) Rost., p. 223.

Sporangia crowded in a globose or more or less hemispheric, expanded head, borne upon a spongy, stem-like, sulcate hypothallus 3–4 mm. high, their apices rounded, their walls very thin, evanescent; spores in mass umber-brown, small, about 5 µ, the epispore reticulate as in the preceding species.

This differs from number 1 chiefly in the cushion-like receptacle on which the crowded sporangia are borne, and in the smaller spores. The species originates in a plasmodium at first colorless, then white, followed by salmon or buff tints, which pass gradually into the dark brown of maturity. This peculiar succession of colors is perhaps more diagnostic than the difference in habit. The spores are, however, constantly smaller in all the specimens we have examined, and the stipitate habit very marked.

New England, New York, south to South Carolina, and west to South Dakota; our finest specimens are from Missouri.

3. Tubifera casparyi (Rost.) Macbr.

Plate XII., Fig. 9.

1876. Siphoptychium casparyi Rost., Mon. App., p. 32.

Sporangia closely crowded, tubular, cylindric or prismatic by mutual pressure, connate, the apices rounded, convex, covered by a continuous membrane, umber-brown; the peridia firm, persistent, minutely granular, iridescent; hypothallus well developed, thin, brown, explanate; pseudo-columellæ erect, rigid, traversing many of the sporangia, and in some instances bound back to the peridial walls by slender, membranous bands or threads, a pseudo-capillitium; spore-mass dark brown or umber, spores by transmitted light pale, globose, reticulate, 7.5–9 µ.

This is Siphoptychium casparyi Rost. In Bot. Gaz., XV., p. 319, Dr. Rex shows that the relationships of the species are with Tubifera; that the so-called columella is probably an abortive sporangium, the so-called capillitial threads having no homology with the capillitial threads of the true columelliferous forms. It is a good species of Tubifera, nothing more. The tubules are shorter than in either of the preceding species; the spores are darker, larger, and more thoroughly reticulate.

The plasmodium is given by Dr. Rex, l. c., as white, then "dull gray tinged with sienna color," then various tones of sienna-brown, to the dark umber of the mature æthalium.

New York, Adirondack Mountains; Allamakee Co., Iowa.

3. Alwisia Berk. & Br.

Plate XIX., Figs. 5 and 5 a.

1873. Alwisia Berk. & Br., Jour. Linn. Soc., Vol. XIV., p. 86.

Sporangia ellipsoidal, clustered, stipitate; dehiscence by the falling away of the upper part of the peridium disclosing a persisting pencil of capillitial threads. A single species:—

1. Alwisia bombarda Berk. & Br.

1873. Alwisia bombarda Berk. & Br., Jour. Linn. Soc., XIV., p. 86.

Sporangia gathered in clusters of four to eight, surmounting coalescent, or sometimes divergent stalks, rusty-brown, or pallid, the peridium evanescent above; the coalescing stalks forming, especially below, a clustered column, 2 mm. in height, equalling the sporangia, dull reddish-brown in color; capillitium of rigid, tubular, generally simple threads, attaching above by delicate tips, below by a broader sometimes branching base, sometimes conjoined near the peridial wall, now and then at irregular intervals inflated slightly or anon bulbose, roughened by projecting spinules, one-third the diameter, brownish or yellow; spores reddish-brown, faintly marked by reticulating bands over large part of the surface, 5–5.5 µ.

This peculiar species looks at first very little like a myxomycete. The stiff projecting hairs of the capillitium are hyphal in appearance and under the lens recall the phycomycetes; but the spores and withal the general structure seem to claim recognition here. Rostafinski was inclined to make a trichia of it, because of the hair-like capillitium, and markings on the threads, Massee found indistinct spiral markings even, enough to suit at least the prototrichias. Mr. Lister would put it near the tubifers. Father Torrend thinks of the dianemas, margaritas, etc., because of simple capillitium attached above and below! Spore-characters are probably the index most reliable, and the partial reticulation suggests association with Tubifera and for the present it may find station there, as in the English monograph.

Rare. Collected three times: twice in Ceylon, once in Jamaica. By the courtesy of Dr. Farlow, late lamented, we record the western specimens.

D. RETICULARIACEÆ

Fructification æthalioid; the sporangia sometimes poorly defined, intricately associated, borne on a common hypothallus and covered above by a common cortex; the lateral walls variously perforate and incomplete, form a pseudo-capillitium; spores umber or ochraceous.

Key to the Genera of the Reticulariaceæ

A. Spores umber.

a. Sporangia wholly indeterminate, their walls much consolidated below, fraying out above into long, slender threads,1. Reticularia

b. Sporangia bounded, more or less distinctly, by broad perforate plates throughout2. Enteridium

B. Spores ochraceous3. Dictydiæthalium

1. Reticularia (Bull.) Rost.

1791. Reticularia Bulliard, Champ. de la France, p. 95, in part.

1873. Reticularia (Bulliard) Rost., Versuch, p. 6.

Plasmodium at first white, then pink, 'ashes of roses,' etc. Sporangia wholly indeterminate or undefined, their walls represented (?) by a spongy mass of so-called capillitium, consisting of membranous plates, branching, anastomosing, vanishing without order or symmetry, generally giving rise at the sides, and especially above, to long slender flexuous threads; outer cortex silvery white; hypothallus distinct, white; spore-mass and threads umber or rusty brown.

A single species,—

1. Reticularia lycoperdon (Bull.) Rost.

Plate X., Figs. 7, 7 a; Plate XII., Fig. 3.

1791. Reticularia lycoperdon Bull., Champ. de la France, p. 95.

Æthalium pulvinate, 2–8 cm. broad, at first silvery white, later less lustrous, the cortex irregularly and slowly deciduous; hypothallus at first conspicuous as a white margin extending round the entire aethalium, evanescent without, but persisting as a firm membrane beneath the spore-mass, pseudo-capillitium abundant, tending to form erect central masses which persist long after the greater part of the fruit has been scattered by the winds; spore-mass umber, spores by transmitted light pale, reticulate over about two-thirds of the surface, the remainder slightly warted, 8–9 µ.

Not common. Often confused with the following, the spores of the two forms being very much alike; the internal structure, entirely different, and once compared, the two are thereafter easily distinguished at sight by external characters. The sporangial make-up is indifferent, confused. It represents a phase in development whence might issue columellæ with capillitium-branches or distinct tubular sporangia with persisting walls; or are such structures here but reminiscent only? Compare Amaurochaete atra, where similar conditions prevail. There differentiation goes on to the formation of a structure of which Stemonitis is type; here the sporangium-wall becomes dominant; suffers modification for spore-disposal, an idea reaching fair expression in Cribraria and Dictydium.

The plasmodium is white, noted Bulliard. Fries cites with approval the words of Schweinitz,—"color corticis ab initio argenteus sericeo nitore insignis; sed deinde sordescit e griseo in subfuscum vergens." Sometimes the surface does indeed shine as silver!

The fructification appears to be isolated in each case; the entire plasmodium consumed in a single plasmodiocarp.

Widely distributed. Maine to California, and south.

2. Enteridium Ehrenberg

1818. Enteridium Ehrenberg, Link and Spreng., Jahrb., Bd. II., p. 55.

Fructification æthalioid; the confluent sporangia inextricably interwoven, the walls perforate by large openings, the resultant network of broad plates and bands widening at the points of intersection.

The genus Enteridium is distinguished from Reticularia chiefly by the more perfectly developed sporangial walls. These are everywhere membranous and do not show the abundant filiform dissipation so characteristic of Reticularia. The resultant structure in Reticularia is a mass of more or less lengthened and anastomosing threads; in Enteridium, an exceedingly delicate but sufficiently persistent sponge. The "net-like, three-winged skeleton" referred to by Rostafinski results from the union at one point of three adjoining sporangia. Compare the section of the adjoining cells of a honeycomb.

Of this genus there are but two or three species, all so far occurring in our territory.

Key to the Species of Enteridium

A. Fructification umber brown1. E. splendens

B. Fructification olivaceous2. E. olivaceum

C. Fructification minute, 1–2 mm.3. E. minutum

1. Enteridium splendens Morg.

Plate I., Figs. 1, 1 a, 1 b; Plate XII., Figs. 4, 5.

1876. Reticularia (?) rozeanum Rost., Mon. App., p. 33.

1889. Enteridium rozeanum (Rost.) Wing., Proc. Phil. Acad., p. 156.

1892. Enteridium rozeanum Wingate, Macbr., Bull. Lab. Nat. Hist. Iowa, II., p. 117.

1893. Reticularia splendens Morg., Jour. Cin. Soc., p. 11.

1899. Enteridium splendens Morg., Morg. in litt.

Æthalium pulvinate, even, or somewhat irregular, unevenly swollen or inflated, lobate or compound, covered by an exceedingly thin, generally smooth, shining, but never white, pellicle or cortex, brown, from 1–6 cm. in diameter; hypothallus white, often wide extending; capillitium none; the sporangial walls thin and brown forming a network as above described; spore-mass umber, spores by transmitted light pale, about two-thirds of the surface reticulate, the rest nearly smooth, 7–9 µ.

Very common, especially west, on decaying logs and stumps of every description. Easily distinguished by its brown color and smooth, shining, though uneven surface. The plasmodium as it emerges to form fruit is pale pink or flesh color, slowly deepening to brown as maturity advances. The first emergence is a watery white.

New England, Canada, to Minnesota and Nebraska, South Dakota.

In 1876 Rostafinski provisionally referred to the genus Reticularia certain specimens received from M. Roze of Paris. Thirteen years later in correspondence with M. Roze, Mr. Wingate satisfied himself that the specimens discovered by Roze were the same as our common enteridium. He therefore, l. c., applied to our American forms the name they have widely borne, E. rozeanum. Mr. Lister, Jour. of Botany, Sept. '91, applied the Rostafinskian name to certain English specimens. Thereafter to be known as Reticularia lobata Rost. and so fixed the status of that species. From all the literature before us it appears that Mr. Lister was right. R. lobata List. (now Liceopsis lobata List.) Torr., occurs in various parts of Europe, while our American species of Enteridium is yet to be discovered on that side of the sea!

Were the latter native to the old world at all, it had surely been seen long ago. It is large and fine, and could not have escaped the famous collectors of the last two hundred years. Although it has been sent by students from this side of the ocean to Europe for more than thirty years, it has not even adventitiously appeared.

It therefore appears that our American species is known to Europe through Mr. Wingate's reference only.

Twenty years ago in correspondence with Mr. Wingate it was learned that the material received by him from M. Roze was but a small fragment, crushed flat, and even this was at that time no longer in evidence. This specimen was itself not part of the gathering submitted to Rostafinski; but only the fragment of something appearing in 1890 in the same locality!

When we further reflect that the spores of species of several of the forms now in review, Tubifera, Reticularia, Enteridium, are not without difficulty distinguished, it is easy to see that Mr. Wingate's specific reference has narrow foundations to say the least. It seems now likely that Father Torrend's Liceopsis, Reticulara lobata R., M. Roze's aftermath, and all, are but the depauperate forms of some tubifera!

E. rozeanum Wing., is therefore the synonym for an ill-defined something in Western Europe and need not further here concern us as far material reference goes.

In any case, what induced Mr. Wingate to pull Rostafinski's uncertain description of a problematic form across the sea, to attach it to our clearly defined and well known American species, changing the Polish description the while to make it fit, is hard to understand; especially in view of the fact, by Wingate admitted, that Rex had in his letters to Morgan already named the American type Enteridium umbrinum. The two students differed as to generic reference, and later on Morgan published Reticularia splendens Morg.; rather than R. umbrina (Rex) Morg. because he was using R. umbrina Fr. for what is generally known as R. lycoperdon (Bull.)

It would then appear that when Wingate sought to impose the Rostafinskian specific name upon our American form by changing (fixing!) Rostafinski's generic reference, and by re-writing the specific description from the pages of the Monograph in order to claim identity, he was entirely without justification, especially since he knew the species appropriately named by his colleague, Dr. Rex, and had the name as used in the Rex and Morgan correspondence.

In brief; Mr. Wingate proceeded to re-describe Rostafinski's rozean specimen and referred a long-known American form (very different) to the European specimen as type. Wingate's description is right; he had the American material before him; but his cited type is worthless, an entirely different thing.

Does the reader care to see what the European type of our common form, Wingate teste, really looks like, let him consult the Jour. of Botany, Vol. XXIX., p. 263, 1891.

2. Enteridium olivaceum Ehr.

1818. Enteridium olivaceum Ehr.

Æthalium depressed flat, oval or elongate, .3 cm. in extent, .6 mm. thick when fresh, glossy, smooth, greenish-olivaceous-brown; within a spongy net-work representing sporangial walls which are thin, pale olivaceous, perforate by circular openings, meshes surrounded by wide plates; spores in clusters, six or more together, ovoid, distinctly warted at the wider end, pale olivaceous, 9–11 µ.

This, the type of the genus, is a very distinct species of this by its structure readily distinguished form. Fries thought the species might represent a less perfectly-developed reticularia, and therefore wrote Reticularia olivacea noting, however, the clustered spores and the lack of hypothallus.

Common, as would appear, in Europe and in S. America; rare with us. Reported from N. Hampshire and we have one specimen from Colorado.

3. Enteridium minutum Sturg.

1917. Enteridium minutum Sturg., Mycologia, IX, p. 328.

Æthalia rounded or elongate, pulvinate, pale umber in color, seated on a broad membranous base, 1.5–2 mm. in diameter; wall wrinkled and usually marked with small scattered pits, pale-yellow, membranous; walls of component sporangia, membranous, minutely roughened, perforated with round openings, the margins of which show many free threads; or reduced to irregular, anastomosing strands arising from the base of the æthalium, with membranous or net-like expansions at the angles and with many delicate, free, pointed ends. Spores pale-yellow, usually united in twos or threes, and ovoid or flattened on one side; when free, globose, very minutely spinulose, 9.5–10.5.

Colorado: Dr. Sturgis.

3. Dictydiæthalium Rostafinski

1873. Dictydiaethalium Rost., Versuch, p. 5.

1875. Clathroptychium Rost., Mon., p. 224.

Æthalium depressed, flat; the sporangia erect, regular, prismatic by mutual pressure, the peridia convex above, wanting at the sides and within the æthalium represented by vertical threads marking the angles and passing from base to summit.

This genus is readily recognized by the internal structure of the æthalium. The lateral wall-openings, which, as we have seen, characterize the sporangia of the preceding genus, here become extreme, occupying to such extent the lateral wall-space of each sporangium that only threads remain to mark the vertical angles.

In 1873 Rostafinski applied the generic name here adopted, because he thought he discovered close relationships with Dictydium. In 1875, believing his first impressions erroneous, and desirous that the nomenclature might not at once mislead the student and perpetuate the memory of his own mistake, the same author proposed the name by which the genus has generally ever since been known—Clathroptychium. However sensible the latter conclusion reached by our Polish author, it is plainly contrary to all rules of priority.

Our region shows but a single widely distributed species,—

1. Dictydiaethalium plumbeum (Schum.) Rost.

Plate I., Figs. 2, 2 a, 2 b.

1803. Fuligo plumbea Schum., Enum. Saell., No. 1410.

1833. Licea rugulosa Wall., Cr. Fl. Ger., IV., p. 345.

1873. Dictydiaethalium plumbeum (Schum.) Rost., Versuch, p. 5.

1875. Clathroptychium rugulosum (Wallr.) Rost., Mon., p. 225.

1894. Dictydiaethalium plumbeum Rost., List., Mycetozoa, p. 157.

Æthalium thin, very flat, olivaceous or ochraceous, smooth, under the lens punctate, in section showing the columnar or prismatic sporangia, which are normally six-sided, having at the edges six simple threads, the remains of peridium, extending from base to apex, where the peridium remains intact, arcuate; hypothallus prominent, radiating far around the æthalium, silvery white; spores in mass, ochraceous, or dull brownish yellow, by transmitted light almost colorless, rough 9–10 µ.

Not rare, on decaying logs, especially of Tilla americana, where in the same place successive fructifications follow each other sometimes for weeks together in the latter part of summer and early fall. The æthalium is generally elliptical or elongate, 2–3 cm. in extent, sometimes irregular or branched, varying in color according to degree of maturity, weathering, etc. Plasmodium at first watery, then pink, or flesh-colored.

Eastern United States; common. Toronto;—Miss Currie.

E. CRIBRARIACEÆ

Sporangia distinct, more or less closely gregarious, stipitate, the peridium opening, especially above, by a well-defined network formed from thickenings in the original sporangial wall.

Key to the Genera of the Cribrariaceæ

A. Peridial thickenings in form of an apical net with definite thickenings at the intersections of the component threads1. Cribraria

B. Peridial thickenings in form of parallel meridional ribs connected by delicate transverse threads2. Dictydium

Cribraria (Pers) Schrader.

1794. Cribraria Persoon, Römer, N. Bot. Mag., I., p. 91, in part.

1797. Cribraria Schrader, Nov. Gen. Plant., p. 1, in part.

1875. Cribraria Rostafinski, Mon., p. 229.

Sporangia distinct, gregarious or closely crowded, globose or obovoid, stipitate; the stipe of very varying length; the peridium simple, marked within by distinct and peculiar, granular, thickenings, which below take the form of radiating ribs, supporting the persisting cup, calyculus, and above, by extremely delicate anastomosing branches, unite to weave a more or less regular net with open polygonal meshes; spores various, more often yellowish or ochraceous, sometimes brown, reddish, or purple.

The genus Cribraria, as limited by Persoon, included all forms in which the peridium is thin, evanescent half-way down, or entirely, and in which capillitium, as Persoon regarded the case, is formed of a network of reticulate threads surrounding the spores. Schrader redefined the genus; opposed Persoon's view as to the capillitial nature of the net, and separated the genus Dictydium, but by imperfect limitations,—in fact, chiefly because of the more completely evanescent peridium. Fries follows Schrader. Rostafinski first clearly separated the two genera, and his classification is here adopted. Nevertheless, after reviewing the subject entire one is more and more inclined to appreciate the commendation of Fries; "Auctor Schrader, qui insuper plurimas species detexit, et hoc et sequens genus ita proposuit ut sequentes vix aliquid addere valuerint."

As to the habitat of the cribrarias, the remark of Schrader is still pertinent—"in vetustissimis plenariæ destructionis proximis arborum truncis"—for all the species. Rotten, coniferous wood seems to be preferred, but the decayed logs of trees of other orders are by no means refused. Rotten oak forms a very common habitat.

Key to the Species of Cribraria

A. Sporangia with spores ochraceous or brownish.

a. Sporangia larger, .5 mm. or more.

1. Net poorly developed, sometimes merely indicated1. C. argillacea

2. Net conspicuous, nodes expanded, not swollen.

i. Calyculus reticulately thickened, ill-defined above2. C. macrocarpa

ii. Calyculus with radiant lines or ribs; net small-meshed; free ends none6. C. aurantiaca

iii. Net wide-meshed, calyx rufous4. C. rufa

iv. Calyx replaced by ribs5. C. splendens

3. Net conspicuous, nodules swollen.

i. Net-threads simple; free ends many7. C. dictydioides

ii. Net-threads often parallel in twos or threes8. C. intricata

b. Sporangia small, less than .5 mm.

1. Nodes not expanded3. C. minutissima

2. Nodes well shown.

i. Calyculus distinctly marked by radiant lines, nodes round10. C. tenella

ii. Calyculus minute or none; nodes prominent11. C. microcarpa

B. Sporangia more or less marked with purple or violet tints.

a. Purple or violet throughout.

1. Net poorly developed12. C. violacea

2. Net well developed.

i. Meshes regular and the nodes distinct14. C. elegans

ii. Meshes and nodules irregular13. C. purpurea

b. Purple tints confined chiefly to plasmodic granules on the calyculus and stipe.

Net with nodes well expanded.

i. Stipe short, not more than double the sporangium; net and calyculus both well developed9. C. piriformis

ii. Stipe many times the sporangium, weak15. C. languescens

iii. Stipe slender, sporangium copper-colored16. C. cuprea

1. Cribraria argillacea Pers.

Plate XII., Figs. 12, 13; Plate XVII., Fig. 1.

1791. Stemonitis argillacea (Pers.) Gmel., Syst. Nat., II., 1469.

1796. Cribraria argillacea Pers., Obs. Myc., I., p. 90.

Sporangia dull ochraceous-olivaceous, globose, nearly 1 mm. in diameter, sessile or short stipitate, closely gregarious or crowded, the peridial walls at maturity smooth, shining, except above, long persistent, obscurely reticulate, with irregular thickenings which at the apex at length present the appearance of an irregular, coarsely meshed net without nodal thickenings; stipe very short, stout, erect, reddish brown, spore-mass ochraceous, spores by transmitted light pale, spinulose, 5–6 µ.

This species stands just on the border-line between the tubiferas and the genus now before us. While on the one hand it possesses many characters such as the habit, form of sporangium, which are distinctly tubuline, on the other it shows in the upper peridial wall definite reticulations which suggest Cribraria. In freshly formed sporangia the reticulations are barely visible in the crown; later on they are more manifest, until, as spore-dispersal proceeds; the cribraria characters come out with sufficient distinctness, and in empty sporangia the reticulations may be seen to affect the entire peridial wall. The nodes are not expanded. The spores are pale by transmitted light, spinulose, about 6 µ. Plasmodium lead-colored. Found sometimes in large patches on rotten logs of various species. Not uncommon. Cf. Lindbladia effusa.

New England, New York, Pennsylvania, South Carolina, Ohio, Illinois, Iowa, Washington; Canada.

2. Cribraria macrocarpa Schrader.

Plate XVII., Fig. 2.

1797. Cribraria macrocarpa Schrad., Nov. Gen. Plant., p. 8.

Sporangia more or less closely gregarious, yellowish brown, pear-shaped or obovate, large, .8–1 mm. in diameter, stipitate; stipe brown furrowed, erect or often nodding, about equal to the sporangium or longer; calyculus distinct, marked by numerous dark brown radiating ribs, iridescent, perforate above, deeply dentate, and merging gradually into the elegant network, of which the dark nodes are more distinctly expanded about half way up, less so at the apex and below, the filaments exceedingly delicate, simple, with occasional free ends projecting into the small meshes; spore-mass yellowish, spores by transmitted light almost colorless, minutely roughened, 5–6 µ.

Perhaps the most striking characteristic of the present species, aside from its large size, is the peculiarly perforated cup or calyculus. Schrader's artist failed him here completely. The structure is exceedingly delicate, the peridium between the ribs and reticulations reduced to the last degree of tenuity, with the iridescence of the soap-bubble, here and there lapsed entirely. Withal the structure seems firm enough and persists until all the spores are dissipated by the wind.

Easily distinguished from the preceding, its only rival in size, by the obovate or turbinate, netted sporangium, its much longer stem, and flat, perfectly formed nodes.

Rare. New York, North Carolina, South Carolina, Oregon; Toronto, Canada.

3. Cribraria minutissima Schweinitz.

Plate XVII., Figs. 6, 6 a.

1832. Cribraria minutissima Schw., N. A. F., No. 2362.

Sporangia scattered, orange or nut-brown, very minute, .1–.3 mm. or less, globose or ellipsoidal, stipitate, erect or nodding; hypothallus none; stipe short, 1–3 times the sporangium, filiform, tapering upward, brown; the calyculus variable, sometimes well marked and separated from the net when fully mature, by a shallow constriction, more commonly small or entirely wanting, especially in the spherical sporangia; net simple, large meshed, without nodal expansions, the threads flattened; spore-mass yellow, spores by transmitted light, pale, nearly smooth, 5–6 µ.

A most beautiful tiny species. Generally in all the specimens before us, a perfect, spherical net, firm enough to retain its place and structure after all the spores have been scattered. When mature the spore-mass seems to roll about as a ball, freely within the net, the spores being thus gradually dispersed. The calyculus when present is without veins. C. minima Berk. & C., and C. microscopica Berk. & C. are doubtless the same thing. Grev., II., p. 67, 1823. See also Bot. Gaz., XIX., 397.

Rare. Pennsylvania, South Carolina, Missouri, Iowa; Black Hills, South Dakota.

4. Cribraria rufa (Roth) Rost.

Plate XIX., Fig. 8.

1788. Stemonitis rufa Roth, Fl. Germ., I., p. 548.

1794. Cribraria rufescens Pers., Rœmer, N. Mag. Bot., I., p. 91.

1797. Cribraria fulva Schrad., Nov. Gen. Pl., p. 5.

Sporangia scattered, sub-globose or turbinate, dark or reddish orange, .5–.7 mm. in diameter, erect, stipitate; stipe about equalling the height of the sporangium or longer, dark brown or black; calyculus one-third to one-half the sporangium, the margin toothed, the wall ribbed and continuous with the open wide-meshed net; the network deep yellow or orange, the threads flattened; the nodes not thickened, little differentiated; spores concolorous, by transmitted light, pale yellow, verruculose, 5–7 µ.

Similar to the preceding, but generally much larger and not so much inclined to brown. The size, however, is extremely variable in sporangia from the same plasmodium (reported white), some no larger than those of the species reckoned most minute.

Oregon. Professor Morton Peck.

5. Cribraria splendens (Schrader) Rost.

Plate XIX., Fig. 10.

1797. Dictydium splendens Schrad., Nov. Gen., p. 14.

1801. Cribraria splendens (Schrad.) Pers., Syn. Fung., p. 191.

Sporangia gregarious, globose, dusky yellow when filled with spores, dull or dusky brown when these are discharged, stipitate; stipe long, 3–4 times the sporangium, subulate, erect-nodding, brown; hypothallus none; network brown, with large meshes, imperfectly defined nodes and flattened threads; calyculus none, its place supplied by nine or ten distinct, firm ribs which radiate from the stipe and support the net, branching to blend with its reticulations; spore-mass yellow, spores by transmitted light, colorless, smooth or nearly so, 6–7.5 µ.

Of this species two specimens only are before us, one from Muscatine County, Iowa, and one from Washington (state). The species seems thus to have wide range, but to be exceedingly rare. It differs from all other American forms, so far described, in the peculiar development of the calyculus. Rostafinski emphasizes the persistence of the peridial wall and the peculiar gleaming of the metallic tints, displayed by all the structures. These particulars we have not been able to verify. Such characters may be incident to age or conditions of development. At all events, in forms which in all other respects seem to agree exactly with Rostafinski's descriptions, the colors are dull and without any noticeable iridescence. The spores in our specimens are also a little larger than quoted. Rostafinski gives 5–6 µ; Massee, 5–7 µ.

6. Cribraria aurantiaca Schrader.

Plate XVII., Fig. 3, and XIX., Fig. 7.

1797. Cribraria aurantiaca Schrad., Nov. Gen. Pl., p. 5.

Sporangia gregarious, spherical, dusky or yellowish stipitate, nodding; the calyculus variable, generally prominent, more or less distinctly marked by fine, delicate radiating venules, the margin denticulate, the teeth numerous and slender, supporting the well-defined globose net; network made up of very tenuous threads, forming rather small irregular brownish nodules and showing only here and there a free extremity; stipe generally short, two or three times the diameter of the sporangium, sometimes longer, tapering upward, brown, slender, arcuate above; spore-mass yellow or ochraceous, spores by transmitted light, colorless, 5–6 µ, almost smooth.

This widely distributed and very variable species is generally recognized by the large sporangia, .5–.9 mm., comparatively short stipe, simple net, and more or less orange color. The color is an uncertain thing even in the sporangia, which rise from one plasmodium. Schrader, however, made this feature so far diagnostic that he placed the more pronouncedly yellow forms in the species C. aurantiaca and set off as C. vulgaris forms in which more dusky tints prevail. The dark-colored forms have also usually longer stipes, but so much is dependent upon the climatic conditions prevalent at the time of fruiting, that this feature also is indeterminate. Rostafinski's figures, 21 and 26, Tab. II., show the characteristic nodules and the typical net structure. It is to be observed that Fig. 21 represents higher magnification; otherwise the two figures are very much alike.

New England, New York, Pennsylvania, Maryland and South, Ohio, Washington, California; Canada, Toronto.

7. Cribraria dictydioides Cke. & Balf.

Plate I., Figs. 5, 5 a, 5 b, and XIX., 6, 6 a, 6 b.

1881. Cribraria dictydioides Cke. & Balf., Rav. Fung. Am., 475.

Sporangia gregarious, of medium size, globose, cernuous, stipitate; the stipe long, slender, tapering upwards, dull brown in color; hypothallus none; the calyculus variable, sometimes well developed, as in C. aurantiaca, sometimes rudimentary or represented only by irregular, node-like ribs; the network delicate, the meshes small, few-sided; the nodules large, prominent, brown, irregular, with several radiating, free, projecting threads, beside the single continuous filaments which pass from node to node; spore-mass pale, ochraceous; spores nearly smooth, colorless, 5–7 µ.

This seems to be the most common Cribraria in the Mississippi valley. It is generally distinguished by the scant calyculus and the beautiful richness of its clear delicate net. The stellate nodules especially above, emit filamental rays in all directions, but are, notwithstanding, united by single, unpaired threads only. The calyculus is often entirely absent, and this has been supposed the typical condition; but, on the contrary, there often may present itself a cup as distinct as in C. aurantiaca. See, for this variation, Bot. Gaz. XIX., p. 398. The rather large sporangia, .6–.7 mm., the nodes joined by single threads, the remaining radiant threads, many or few, but very short—these seem to be the most distinctly diagnostic characters, and these are sufficiently constant to separate this species easily from C. intricata on the one hand and C. tenella on the other. Mr. Lister considers this merely a form of the next species.

Abundant on rotten logs of every sort, especially oak; common on the lower side of rotting pine planks in wooden walks along the streets everywhere. N. A. F., 2095, seems to belong here.

Pennsylvania, Ohio, North Carolina, Missouri, Illinois, Iowa, Nebraska.

8. Cribraria intricata (Schrad.) Rost.

1797. Cribraria intricata Schrad., Nov. Gen. Pl., p. 7.

Sporangia gregarious, globose, large, .7–1 mm. in diameter, nut-brown or olivaceous, erect, stipitate; stipe long, slender, purplish brown, flexuous; calyculus variable, sometimes occupying one-third of the sphere, when it is delicately costate, concolorous with the stipe, and passes over to the net by a distinctly toothed or serrulate margin, sometimes represented by irregular ribs or costæ only; net well differentiated, the threads delicate, transparent, yellow, connecting large black nodules, running from one to the other in pairs or sometimes three together, free ends not numerous, the meshes few-sided, often triangular; spores in mass, dull olivaceous, under the lens pallid, nearly smooth, 6–7 µ.

A very rare species, if indeed it occur in this country. At least the form figured by Rostafinski, Tab. II., Fig. 27, and Massee, Pl. 1, Fig. 11, has not come to our notice. The parallelism of the net threads is a touch added by Rostafinski; Schrader does not mention it. Lister makes this species include the preceding. The form described in Bull. Lab. Nat. Hist. Ia. II., p. 119, is C. dictydioides.