白藓科 bai xian ke
by Jia Yu and Li Zhi-hua
Plants slender, soft, whitish to yellowish green, somewhat shiny, in loose mats. Stems creeping, rarely pendulous, sometimes with clusters of rhizoids, irregularly or rarely pinnately branched, slightly complanate; central strand lacking; paraphyllia absent. Leaves contorted when dry, more or less flattened when wet, slightly asymmetric, becoming narrow at base, oblong-ovate, gradually lanceolate above, apices acute to acuminate; leaf margins entire; ecostate, occasionally with indistinct short double costae; laminal cells loose, thin-walled, elongate-hexagonal or lineariform, short at base; alar cells not differentiated. Monoicous, dioicous or autoicous. Perichaetial leaves broad at base, abruptly narrowed to a short acuminate apex, leaf margins entire. Setae slender, slightly coarse above, smooth below, reddish brown; capsules ovoid or oblong-ovoid, horizontal or nearly cernuous, stomata superficial; annuli large, usually persistent; peristome double; exostome teeth narrowly lanceolate, thin, hyaline, longitudinal furrows in the center, with dense ridges and stripes outside, densely striate; endostome segments densely papillose, folded; cilia absent or poorly developed, slightly higher than the mouth; opercula conic, with short or slender beak. Calyptrae cucullate, smooth, covered with spare hairs, entire at base or lobed. Spores minute, nearly smooth.