Plants small to large, dark green, greenish brown or reddish brown, often in tufts, cushions, or mats on tree trunks, sometimes on rocks. Stems erect or prostrate, short or elongate, simple or branched, with dense rhizoids; central strand absent in cross section. Leaves crowded, appressed, contorted or flexuose, often curled, spirally twisted when dry, erect-spreading to recurved or squarrose when moist, usually lanceolate, oblong-lanceolate to ovate-lanceolate or elliptic, occasionally lingulate, usually keeled, acuminate, acute, or apiculate, rounded-obtuse at apex; margins mostly entire, plane or recurved; costae single, strong, ending near the apex to shortly excurrent; upper leaf cells often small, rounded-hexagonal, shortly rectangular, occasionally elongate, firm-walled to thick-walled, often papillose, sometimes bulging to mammillose, rarely smooth; lower cells elongate-rectangular to linear at the base, often incrassate, hyaline or yellow; alar cells not differentiated. Autoicous or dioicous. Inner perichaetial leaves not or slightly differentiated, rarely vaginate. Setae very short to elongate; capsules erect, immerse to exserted, often symmetrical, ovoid or cylindrical, rarely pyriform, usually deeply furrowed, sometimes puckered at the mouth; opercula conic-apiculate to rostrate; annuli usually present; peristome usually double, sometimes single, rarely absent; prostome sometimes present; exostome teeth 16, lanceolate, often united or in pairs, often densely papillose, or striolate at the base; endostome segments thin, 0, 8, or 16, linear or lanceolate, often reduced, smooth or ornamented; basal membrane low to absent; cilia absent. Calyptrae cucullate or mitrate, often plicate, naked or hairy. Spores spherical, unicellular or multicellular, often papillose.