Family: Stereophyllaceae

Diagnosis: Plants medium-sized to moderately robust, in often lustrous, green to golden, thin to dense, flat mats. Stems creeping, simple or sparingly branched, terete- or complanate-foliate. Stem and branch leaves similar, crowded or sometimes lax, usually imbricate when dry, erect to wide-spreading when moist, lanceolate to ovate, obtuse to long-acuminate, symmetric or rarely asymmetric, flat to somewhat concave, not plicate, not decurrent; margins usually serrulate above, ± entire below, mostly plane; costa mostly single, ending 1/3-3/4 the leaf length, rarely weaker or absent in some leaves, occasionally projecting as a spine or prickle at apex; cells rhomboidal to linear, smooth or rarely unipapillose or prorulose at upper ends at back, thin- to thick-walled; alar cells differentiated in mostly large areas, oblate or quadrate to rectangular, often unequally distributed on either side of the costa but always covering the adaxial surface of the costa. Setae elongate, straight; capsules erect to cernuous, straight to arcuate, ovoid to cylindric; annulus differentiated and deciduous or undifferentiated; operculum conic to short-rostrate; peristome double, shouldered, bordered, on the front surface with a zig-zag median line, cross-striolate or with horizontal arranged papillae below, papillose above. Calyptra cucullate, naked, smooth. Spores spherical to ovoid, papillose.