DITRICHACEAE
牛毛藓科 niu-mao xian ke
by Cao Tong and Si He
Plants mostly minute to small, or at times to medium-sized, gregarious or in loose tufts, sometimes densely caespitose. Stems erect, simple or branched; central strand present or poorly developed or absent. Leaves usually lanceolate, acuminate or subulate, sometimes sheathing at base, seldom distichous; margins plane, reflexed or revolute, entire or serrulate; costa single, narrow, subpercurrent to long-excurrent; cells subquadrate or short-rectangular to linear, mostly smooth or occasionally mammillose; alar cells not differentiated. Sporophytes terminal; setae usually elongate, straight, sometimes very short; capsules often long-exserted, at times immersed to emergent, subglobose to cylindric, erect to inclined or curved, asymmetric; opercula often differentiated, conic or long-rostrate, sometimes absent; annuli mostly differentiated; stomata absent or present; peristome none or present with 16 teeth, divided in terete division or perforated nearly to the base, without vertical pitted-striolation or with oblique striolation. Calyptrae cucullate, rarely mitrate. Spores small, spherical, minutely papillose.