Plants: small, in low mats, yellowish to whitish, shiny. Stems: creeping, regularly or irregularly pinnate, branches usually strongly curled when dry; hyalodermis absent, central strand present, small; pseudoparaphyllia foliose. Stem: and branch leaves similar. Stem: leaves appressed when dry, erect-spreading when moist, ovate-lanceolate, widest beyond base, not or slightly plicate; base not or weakly decurrent; margins plane, sometimes slightly involute distally, subentire to serrulate distally; apex acuminate; costa double and short or indistinct; alar cells differentiated, subquadrate to rectangular; laminal cells smooth; distal cells usually longer than 6:1. Branch: leaves narrowly ovate- to oblong-lanceolate, smaller to occasionally somewhat larger than stem leaves. : Specialized asexual reproduction absent. Sexual: condition autoicous; inner perichaetial leaves erect, oblong-lanceolate, apex subulate. Seta: yellowish or reddish. Capsule: erect to suberect, oblong-cylindric to oblong-ovoid, straight, not contracted below mouth; annulus differentiated or not; operculum conic to rostrate, obliquely short- to long-acute or obtuse; peristome perfect to reduced, hygroscopic; exostome teeth with external surface smooth basally, sometimes roughly papillose distally; endostome basal membrane present, segments sometimes 2-fid or fragmentary, keeled, cilia rudimentary. Calyptra: naked. Spores: spheric [somewhat tetrapozoidal by endosporic protonemata], finely papillose. North America, Mexico, Central America, South America (Andes Mountains), Europe, Asia.
Species 16 (4 in the flora). Pylaisia has yellowish brown stems 2 cm long and reddish capsules; the exothecial cell walls are thin. The setae are sinistrorse-twisted basally and dextrorse-twisted distally when dry; the capsules have few phaneropore stomata on the base of the neck; and the exostome teeth are lance-subulate to blunt, distinctly lamellate, and internally trabeculate.