Fabronia Raddi

Plants small, silky, pale or dark green, forming loosely interwoven mats. Stems appressed or weakly ascending from the substrate, irregularly branched, fragile, with fascicles of smooth, pale brown rhizoids arising at leaf bases. Stem and branch leaves not differentiated, spreading when moist, erect and ± secund when dry, ovate to lanceolate, often acuminate, lacking plications, plane, spinose, ciliate, or sometimes entire; upper laminal cells usually rhombic-hexagonal, smooth; alar cells quadrate or oblate in several rows at the margins. Costa single and weak. Paraphyllia absent.

Mostly monoicous. Perichaetia and perigonia scattered on stems. Setae pale, smooth; capsules erect, ± obovoid, usually ± constricted below the mouth when dry; mouth transverse; exothecial cells thin-walled and sinuose; stomata few and superficial, restricted to neck; operculum mammillate, convex or short-rostrate. Peristome single, exostomal, rarely lacking; exostome teeth paired, reflexed or erect when dry and incurved when moist, variably ornamented. Calyptra cucullate. Spores spherical to ellipsoid, smooth or ornamented.

Fabronia is widely distributed in tropical to warm temperate regions, occurring primarily on tree trunks. While Brotherus (1925) recognised 88 species, a modern treatment for South America (Buck 1983) reduced some 53 described entities to merely 5 recognised taxa. A single variable species occurs in N.Z.