1. Aerobryidium M. Fleisch ex Broth. 毛扭藓属 mao niu xian shu
Nat. Pflanzenfam. I(3): 20. 1906.
Plants slender, rather rigid, green, yellowish green, or brownish green, slightly glossy. Primary stems creeping; secondary stems pendulous, regularly or irregularly pinnately branched, with tufted rhizoids. Leaves oblong, oblong-ovate, or ovate-lanceolate, usually erect-patent, often with slender, flexuose hairy apices; margins nearly entire or serrulate above; costae slender, reaching above mid-leaf; median leaf cells rhomboidal, elongate-rhomboidal to linear, unipapillose, usually thin-walled; basal cells lax; alar cells not or scarcely differentiated; axillary hairs 6–8 cells long, hyaline. Dioicous. Setae slender, usually reddish brown, sometimes papillose; capsules ovoid or oblong-ovoid, usually erect; opercula conic, obliquely rostrate; peristome double; exostome teeth lanceolate, densely papillose, often striolate at the base; endostome segments narrowly lanceolate, finely papillose; basal membrane low or high; cilia short or absent. Calyptrae cucullate, sparsely hairy. Spores spherical, finely papillose.