Leucobryum Hampe, Flora 20: 282. 1837.
Plants in compact or loose cushions or mats; stems simple or forked to irregularly branched, 1–20 cm high; central strand of small, thin-walled, frequently fugacious cells; rhizoids red-brown, on stems and from apex of leaves. Leaves appressed, imbricate, elliptic-ovate at base, erect-spreading, straight or flexuous, subtubulose, at times falcate-secund above, consisting mostly of a broad costa; apex acute or obtuse and cucullate; margins incurved above, entire, or weakly denticulate at the apex; cross section at base with a median row of small, green quadangular cells (chlorocysts) enclosed by 2–8 layers of enlarged, hyaline cells (leucocysts); leaf lamina present from leaf base to midleaf, consisting of a narrow (2–12 rows of cells) marginal band of hyaline, linear, long-rectangular, short-rectangular or quadrate, variably porose, firm- to lax-walled cells. Asexual reproduction by apical clusters of reduced, deciduous leaves. Pseudautoicous; male plants minute, growing on tufts of tomentum or leaves of female plants. Perichaetial leaves at times differentiated and shortly sheathing. Setae elongate; capsules cylindrical, curved or rarely erect, commonly strumose, ribbed or smooth when dry; stomata absent; annuli mostly nonrevoluble; peristome teeth divided 1/2 the distance to the base, vertically-striate, papillose or smooth on outer surface. Calyptrae cucullate, entire.