Hypnaceae

Diagnosis: Plants small to medium-sized, dark green to golden, often extensive, loose mats. Stems stipitate, mostly arched, usually wiry, radiculose at tips, freely and irregularly branched, sometimes subcomplanate-foliate. Stem leaves often differentiated, mostly wide-spreading to squarrose, broadly ovate, gradually or ± abruptly acuminate, stem and branch leaves similar but stem leaves larger; margins serrate to serrulate; costa short and double, sometimes to 1/3 the leaf length, often with one fork longer than the other; cells linear, prorulose at upper ends at back of usually some cells but rarely all, rarely smooth; alar cells few in extreme angles, quadrate to subquadrate. Setae elongate, reddish; capsules horizontal to pendent, arcuate, asymmetric, cylindric, usually with a differentiated neck, often constricted below the mouth when dry; annulus differentiated; operculum short to medium conic-rostrate; peristome double, exostome teeth shouldered, bordered, on the front surface cross-striolate below, papillose above. Calyptra cucullate, naked or with a few scattered hairs, smooth. Spores spherical, finely papillose.