Part 12

B. Stipe and columella white or yellowish.

6. DIACHAEA. Threads of the capillitium branching and anastomosing to form a network.

I. CLASTODERMA, Blytt. Sporangium regular, globose, stipitate; the wall very thin and fragile. Stipe elongated, tapering upward, entering the sporangium as a very short or nearly obsolete columella. Capillitium arising by a few branches from the apex of the columella, these branches forking several times at a sharp angle, but not combined into a network, the ultimate branchlets long and free, or only connected together at their tips by persistent fragments of the sporangial wall. Spores globose, violaceous.

The claim of this genus to be distinguished from Lamproderma must rest upon the fact that the branchlets of the capillitium do not anastomose and form a network. It is the same as the genus Orthotricha of Wingate.

1. CLASTODERMA DE BARYANUM, Blytt. Sporangium very small, globose; the wall early disappearing, except the minute fragments which persist at the extremities of the capillitium, and a narrow collar at the base of the columella. Stipe very long, thick and brown below, tapering upward to a pellucid oblong swelling, thence abruptly narrowed to the apex; the columella extremely short, capillitium of very slender pale-brown semi-pellucid threads, divergently forking, the ultimate branchlets often joined 2-4 together at their tips by fragments of the sporangial wall. Spores globose, even, violaceous, 8-9 mic. in diameter. See Plate XI, Fig. 25.

Growing in rather a scattered way on old rotten wood. Sporangium .20-.25 mm. in diameter, the stipe .7-1.3 mm. long. Orthotricha microcephala, Wingate. Blytt's species was found in Norway, Wingate's in Pennsylvania; I have met with it several times in this locality. It is possibly more common than it appears, as by reason of the difficulty of seeing the minute sporangium it is passed by as some mold. Blytt's spore measurements are 9.5-11 mic.; in some specimens I have seen a few spores of this size, but they are abnormal.

II. LAMPRODERMA, Rost. Sporangia regular, globose, stipitate; the wall thin and fragile, rugulose, shining with metallic tints, breaking up irregularly and gradually falling away. Stipe more or less elongated, smooth, brown or black in color, arising from a hypothallus, tapering upward and entering the sporangium as a short columella scarcely reaching the center. Capillitium of numerous threads radiating from the columella, usually forking several times and combined into a net by lateral anastomosing branchlets. Spores globose, brown or violaceous.

Lamproderma is distinguished by the shining metallic tints of the sporangial wall, and by the short columella scarcely reaching half the height of the sporangium.

1. LAMPRODERMA PHYSAROIDES, A. & S. Sporangium globose; the wall with a silvery metallic luster, at length breaking up and falling away. Stipe long, slender, brown or blackish, arising from a small circular hypothallus; columella clavate, obtuse, not reaching the center of the sporangium. Capillitium of brownish-violet threads, arising from the upper part of the columella; these branch repeatedly at a sharp angle, form an intricate network of elongated meshes, terminating at the wall in numerous short free branchlets. Spores globose, minutely warted, bright brown, 12-14 mic. in diameter.

Growing on old wood, moss, etc., New York, Chas. H. Peck. Distinguished by the pale silvery sporangial wall and the clear brown spores.

2. LAMPRODERMA ARCYRIONEMA, Rost. Sporangium small, globose; the wall dark bronze, with a silvery sheen when loosened from the spores, soon breaking into scales and falling away. Stipe long and slender, smooth, shining and black, rising from a thin hypothallus; the columella short cylindric, variable in length, but not attaining the center of the sporangium. Capillitium arising by division of the apex of the columella into several primary branches; these immediately separate into numerous slender flexuous brown threads, which unite and form a dense network of small arcuate meshes, the ultimate branchlets not free. Spores globose, even, violaceous, 6-7 mic. in diameter. See plate XI, Fig. 26.

Growing on old wood of Juglans and Carya. Sporangium .3-.5 mm. in diameter, the stipe three or four times as long. The columella is somewhat variable, it sometimes forks or divides immediately on entering the sporangium, at other times it is longer and cylindric, with more slender primary branches. The meshes of the capillitium resemble those of Arcyria, whence the name. This is the Stemonitis physaroides, A. & S. var. suboeneus of Lea's Catalogue.

3. LAMPRODERMA VIOLACEUM, Fr. Sporangium depressed-globose, convex above and more or less flattened and umbilicate beneath; the wall shining with steel or violet, blue and purple tints, deciduous. Stipe short, stout, brown or blackish in color, arising from a thin, brown, common hypothallus; columella cylindric, or tapering slightly to an obtuse apex, attaining the center of the sporangium. Capillitium of numerous slender threads, radiating from the upper part of the columella; these threads are brown below, with a variable outer portion colorless; they branch a few times and form an interior network of elongated meshes, outwardly arching and freely anastomosing they give rise to an external network of small irregular meshes, they then attain the wall by innumerable short, simple, or forked free branchlets. Spores globose, minutely spinulose, violaceous, 9-11 mic. in diameter. See plate XI, Fig 27.

Growing on old wood, mosses, etc., late in Autumn. Sporangium .5-.8 mm. in diameter, the stipe about the same length. The capillitium is sometimes most of it colorless and flaccid; sometimes it is all brown and rigid except the minute free extremities.

4. LAMPRODERMA ARCYRIOIDES, Somm. Sporangium globose or ellipsoid, and somewhat elongated; the wall with tints of violet, purple, and blue, deciduous. Stipe usually short, or sometimes nearly obsolete, brown or blackish in color, arising from a strongly-developed hypothallus; the columella cylindric or slightly tapering upward, and obtuse, reaching nearly to the center of the sporangium. Capillitium of numerous pale-brown threads, radiating from the apex of the columella; these fork directly from the base, are bent and flexuous, and are combined into a dense, intricate net, with abundant free extremities. Spores globose, spinulose, violaceous, 13-16 mic. in diameter.

Growing on old leaves, wood, etc. Sporangium .5-.8 mm. in diameter, the stipe variable in length from very short to 1 mm. long or beyond. Lamproderma columbinum, Pers. is a doubtful species, the forms of that name being easily distributed between the present species and L. physaroides.

5. LAMPRODERMA SCINTILLANS, B. & Br. Sporangium globose; the wall shining with colors of blue, purple, and bronze, deciduous. Stipe long, slender, smooth, and shining, brown or blackish, rising from a thin, brown, common hypothallus; columella cylindric or slightly tapering to the obtuse apex, not reaching the center of the sporangium. Capillitium of numerous brown threads, originating about the apex of the columella; these fork several times, with few anastomosing branchlets, and terminate at the wall in long, free extremities. Spores globose, minutely warted, violaceous, 7-9 mic. in diameter. See Plate XI, Fig. 28.

Growing on old leaves, moss, etc., in early Spring. Sporangium .3-.5 mm. in diameter, the stipe from once to twice as long. This is Lamproderma irideum of Massee's Monograph. I am indebted to Arthur Lister, Esq., of London, for the identification of my specimens with Stemonitis scintillans, B. & Br., and with Lamproderma irideum, Cke.

III. COMATRICHA, Preuss. Sporangia various in shape, from globose or ovoid to oblong and cylindric, stipitate; the wall very thin and fugacious. Stipe more or less elongated, smooth and black, arising from a common hypothallus, tapering upward, entering the sporangium and prolonged nearly or quite to the apex as a columella. Capillitium arising from numerous points of the columella throughout its entire length; the threads immediately branching and anastomosing to form an interior network, attaining the wall by numerous more or less elongated free extremities. Spores globose, brown or violaceous.

This genus is not sharply limited from Stemonitis. The species with very short free ends, and consequently with superficial meshes approximate to the wall, are near the form of Stemonitis. But it may be observed that in these species, the meshes of the capillitium become smaller gradually outward, the sides of the superficial meshes are arched away from the wall, and they are in contact with it only by the free extremities.

§1. TYPHOIDES. Threads of the capillitium repeatedly branching and anastomosing, to form a dense network of small meshes, with innumerable short, free extremities.

1. COMATRICHA TYPHINA, Roth. Sporangia short, erect or a little curved, cylindric or usually narrowing slightly upward, the base quite blunt, the apex more rounded, growing together on a thin hypothallus. Stipe and columella brown or blackish, tapering upward and vanishing near the apex of the sporangium, the stipe much shorter than the columella. Capillitium of slender flexuous tawny-brown threads; these branch repeatedly, forming an intricate network of small irregular meshes, ending in very short free extremities. Spores globose, violaceous, very minutely warted, 6-8 mic. in diameter.

Growing on old wood, mosses, etc. Sporangium with the stipe 2-4 mm. in height, the stipe much the shorter, the sporangium .35-.40 mm. in thickness. Stemonitis typhoides, Fries, S. M.

2. COMATRICHA ÆQUALIS, Pk. Sporangia usually more or less inclined or curved and nodding, cylindric, obtuse at each end, growing together on a thin hypothallus. Stipe and columella slender, smooth, black, extending nearly or quite to the apex of the sporangium, the stipe longer than the columella. Capillitium of very slender flexuous tawny-brown threads; these branch repeatedly, forming an intricate network of small irregular meshes, ending in very short free extremities. Spores globose, minutely warted, dark violaceous, 7-9 mic. in diameter.

Growing on old wood. Sporangium 1.5-3 mm. in height by .35-.40 mm. in thickness, the stipe usually about the same length as the sporangium, but sometimes nearly twice as long. The capillitium is rather looser than in C. typhina, whence the drooping habit. Peck, Thirty-first Report, p. 42.

3. COMATRICHA NIGRA, Pers. Sporangia globose or ovoid to ellipsoid or oblong, erect or sometimes inclined or even nodding. The stipe very long, smooth and black, tapering upward, expanding at the base into a small circular hypothallus; the columella short, reaching from one-half to three-fourths the height of the sporangium. Capillitium of slender flexuous brown threads, which branch repeatedly, forming a dense intricate network of small meshes, ending in very short free extremities. Spores globose, even, dark violaceous, 8-10 mic. in diameter.

Growing on old wood, leaves, etc. Sporangium .5-1.5 mm. in height, .5-.8 mm. in diameter, the stipe 1.5-3 mm. long or sometimes considerably longer. This species seems to be rare in this country. I have preferred the name adopted by Schroeter to Rostafinski's Comatricha Friesiana.

4. COMATRICHA ELLISII, Morgan, n. sp. 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. See Plate XI, Fig. 29.