5. N. fossombronioìdes, Lindb. Stems densely cespitose, ascending; rootlets numerous, purple; leaves 2-ranked, subvertical, spreading-subrecurved, rooting, closely imbricate, orbicular, clasping by a slightly cordate base, subventricose, undulate-repand, the apex uniplicate and slightly emarginate; monœcious; perianth very large, 6–10-plicate, the lobes entire; calyptra violet; capsule short-oval. (Jungermannia fossombronioides, Aust.)—On rocks in a rivulet, Closter, N. J. (Austin), and southward.
27. GYMNOMÍTRIUM, Corda. ([Pl. 23.])
Leaves closely imbricated, 2-ranked on fascicled ascending julaceous stems, emarginate-bidentate; underleaves none. Diœcious. Involucre double, the inner shorter, of 2 or more dentate and deeply cleft leaves. Calyptra short, campanulate. Capsule globose, the valves at length reflexed. Elaters caducous. Antheridia in the axils of leaves, oval, stipitate. (Name from γυμνός, naked, and μιτρίον, a little cap.)
1. G. concinnàtum, Corda. Stems simple or imbricately branching, thickened at the apex; leaves ovate, bifid, with a narrow scarious margin. (Cesia concinnata, S. F. Gray.)—Alpine regions of the White Mts. (Oakes).—Grayish or silvery-olive. (Eu.)
28. FOSSOMBRÒNIA, Raddi. ([Pl. 23.])
Stems thalloid, with large subquadrate succubous leaves; underleaves none. Diœcious or monœcious. Fruit terminal or by innovation dorsal on the main stem. Involucral leaves 5–6 (in our species), small, subulate, adnate. Perianth open-campanulate or obpyramidal, crenate-lobed. Calyptra free, sub-globose. Capsule short-pedicelled, globose, irregularly valved. Elaters very short, 1–3- (mostly 2-) spiral, free. Spores large, very rough. Antheridia 2–3, short-pedicelled, naked. Perfect archegonia 2–3. (Named for V. Fossombroni, an Italian Minister of State.)
[*] Plant large or of medium size; stems mostly simple.
1. F. pusílla, Dumort. ([Pl. 23.]) Stems 6–10´´ long; leaves retuse, entire or irregularly indented; perianth obconic, dentate; elaters short and thick; spores brown, depressed-globose-tetrahedral, 40 µ broad, crested, the slender crests pellucid, rarely becoming confluent.—On damp ground. Its occurrence in America is doubtful. (Eu.)
2. F. Dumortièri, Lindb. Cespitose, greenish or brownish-yellow; stems 3–6´´ long, 1´´ wide, shortly bifurcate; rootlets copious, purple; leaves numerous, smaller toward each end of the stem; monœcious; perianth large, broadly obpyramidal; calyptra nearly as long; elaters scanty; spores globose-tetrahedral yellowish-brown, regularly pitted.—White Mts. (Farlow), N. J. (Austin), and perhaps elsewhere; confused with n. 1.
3. F. angulòsa, Raddi. Stems narrowly forked at the apex; leaves horizontal, subquadrate, the upper undulate-lobed; diœcious; perianth dilated-conic, crenate; spores brownish-yellow, globose-tetrahedral, not depressed, 30 µ broad, deeply reticulated, the reticulations large, 5–6-angled.—Brackish meadows, common; fruiting in early spring. (Eu.)