树生藓科 shu sheng xian ke
by Wang Mei-zhi
Plants small, slender, soft, bright green to dark green, or grayish green to yellowish green, in loose tufts. Stems creeping, closely attached to substrate when dry, somewhat ascending when moist, irregularly to subpinnately branched, often with a few rhizoids at the base; central strand present or absent. Leaves in 3–4 or more rows, often differentiated into ventral and dorsal leaves, ventral and dorsal leaves dimorphic or more or less similar, imbricate when dry, erect-spreading when moist, sometimes complanate, ovate, oblong-ovate or ovate-lanceolate, concave or plane, not plicate, obtuse, acute or acuminate at the apex; margins entire; costae none; median leaf cells hexagonal or rhombic, smooth or papillose, usually thin-walled; sometimes marginal cells differentiated; alar cells slightly differentiated. Autoicous. Perichaetial leaves large, erect. Setae short or elongate; capsules erect, ovoid or cylindrical, with a short neck; opercula conic at the base, shortly rostrate; annuli well developed or absent; exothecial cells often colored at the mouth; stomata present; peristome absent or with single layer of 16 teeth, straight or curved, lanceolate, papillose. Calyptrae cucullate or mitrate, often split or vertically furrowed. Spores spherical, papillose.