5. S. nemoròsa, Dumort. Rather stout, flexuose, creeping at base; leaves rather distant, decurrent on both sides, ciliate-dentate, the lower lobe obovate, obtuse, slightly convex, the upper cordate, acute, concave; perianth densely ciliate; capsule large, roundish-ovate, reddish-brown. (S. breviflora, Tayl.)—On rocks, etc., in swamps and rills; common and variable. (Eu.)
6. S. Oakèsii, Aust. Leaves obovate, somewhat spreading, often deflexed, closely complicate, convex, the lower lobe coarsely dentate, and with deep purple spur-like teeth on the keel, the upper roundish and less dentate; perianth usually dentate.—White Mts. (Oakes, Austin).
[*][*][*] Lower lobes 3–4 times the size of the upper.
7. S. exsécta, Aust. Ascending; leaves subcomplicate, entire, the lower lobe ovate, acute or bidentate, concave, the upper small and tooth-like; involucral leaves 3–5-cleft; perianth oblong, obtuse, plicate. (Jungermannia exsecta, Schmidel.)—High mountains, far northward; rare.—Perhaps better retained in Jungermannia. (Eu.)
8. S. umbròsa, Dumort. Stems short, decumbent, slightly branched; leaf-lobes ovate, acute, serrate; perianth incurved, naked at the mouth.—White Mts.; rare.—The tips of the shoots are frequently covered with a dark mass of gemmæ. (Eu.)
16. DIPLOPHÝLLUM, Dumort. ([Pl. 25.])
Leaves rather narrow, complicate-bilobed, the lobes subequal or the upper smaller, the lower succubous; underleaves none. Fruit terminal. Involucral leaves few. Perianth cylindrical, scarcely or not at all compressed, pluriplicate, denticulate. (Name from διπλός, double, and φύλλον, leaf, on account of the folded 2-lobed leaves.)
1. D. álbicans, Dumort., var. taxifòlium, Nees. Stems ascending, almost rootless; leaves closely folded, subdenticulate, with a rudimentary pellucid line near the base or none, the lobes obtuse or acutish, the lower oblong-scymitar-shaped, the upper smaller, subovate; perianth ovate, plicate. (Jungermannia albicans and J. obtusifolia of Sulliv.; not of L. and Hook.)—Under rocks in mountain ravines and on the ground. (Eu.)—The typical form occurs in N. Scotia, distinguished by a broad pellucid median line in both lobes.
17. GEÓCALYX, Nees. ([Pl. 23.])
Leaves succubous, bidentate; underleaves 2-cleft, with linear divisions. Fruit lateral, pendent. Involucre simple, fleshy, saccate, oblong, truncate, attached to the stem by one side of the mouth. Calyptra membranous, partly adnate to the involucre. Capsule oblong. Elaters free. Antheridia in the axils of small leaves on spike-like lateral branches. (Name from γέα, the earth, and κάλυξ, a cup, from the subterranean involucres.)