13. J. incìsa, Schrad. Stems thick, rooting, closely creeping or ascending; leaves crowded, semi-vertical, complicate, subquadrate, 2–6-cleft, the acute lobes unequal, more or less spinulose-dentate; involucral leaves similar, more plicate and dentate, free; perianth short, oval or obovate, plicate above, denticulate.—On rotten wood in the mountains, and northward. (Eu.)
§ 3. SPHENÓLOBUS. Leaves 2-lobed, subtransverse, complicate-concave; underleaves none; involucral leaves 2–3-cleft. (Verging toward Marsupella on one side and Diplophyllum on the other.)
14. J. Michaùxii, Weber. Stems ascending, flexuous by repeated innovations below the summit; leaves crowded, subvertical, erect-spreading, subsaccate at base, subquadrate, bifid with straight acute lobes and a narrow sinus; involucral leaves similar, the outer serrulate, the inner smaller; perianth ovate-subclavate, obtuse, plicate above, fringed.—Fallen trunks, mountains of N. Y. and N. Eng.; common. (Eu.)
15. J. minùta, Crantz. Rootless; leaves cleft ¼–½ their length, the lobes ovate, subequal, acute or obtuse, entire, or gemmiparous ones subdentate; involucral leaves trifid; perianth oval-oblong or subcylindric.—On rocks in high mountain regions, and northward. (Eu.)
16. J. Helleriàna, Nees. ([Pl. 25.]) Creeping, entangled; leaves spreading, subascending, cleft {1/3}–½ their length, the lobes equal, acute, entire or serrate; involucral leaves 2–3-cleft, spinulose serrate; perianth ovate, the mouth contracted.—On rotten wood, N. Y., N. Eng., and northward. (Eu.)
§ 4. GYMNOCÓLEA. Leaves 2-lobed; underleaves none; involucral leaves like the cauline; perianth pedunculate, denticulate.
17. J. inflàta, Huds. ([Pl. 25.]) Procumbent or ascending, loosely radiculose, branching; leaves semi-vertical, roundish-elliptic, inequilateral, the sinus and unequal lobes obtuse; perianth terminal or at length dorsal, oval or pyriform, smooth, the mouth connivent; capsule oblong.—On sterile ground and rocks, N. J. (Austin), and northward in the mountains. (Eu.)
25. MARSUPÉLLA, Dumort. ([Pl. 23.])
Stems dorsally compressed, with rootlets at the base and often producing somewhat leafless runners. Leaves transverse, complicate-bilobed; involucral leaves 2 or 4, connate with the perianth. Perianth tubular or oval, subcompressed parallel to the base of the leaves. Elaters free. Spores round, rufous (in our species). Antheridia mostly terminal. (Name a diminutive of marsupium, a pouch, from the form of the perianth.)
1. M. sphacelàta, Dumort. Stems erect, subflexuous, pale brown; leaves rather distant, concave, obovate to obcordate, somewhat clasping, the sinus narrow; diœcious; involucral leaves larger than the cauline, cordate; perianth free at the apex, with 4–5 broad acute teeth; antheridia 1–3, in short terminal spikes.—Wet rocks, mountains of N. Eng. to N. J., and southward. (Eu.)