25. Pterygoneurum Jur. 盐土藓属 yan-tu xian shu
Laubm.-Fl. Oesterr.-Ung. 95. 1882.
Plants tiny, grayish green or yellowish green, bulbiform, gregarious or in thin tufts. Stems very short, erect, simple or sometimes branched at the base; central strand present. Leaves appressed when dry, weakly spreading when moist, ovate to ligulate or elliptic, broadly concave; margins plane or weakly incurved; costa rather stout, excurrent, ending in a long awn, either smooth or denticulate; in cross section only dorsal stereid band present; with 2–4 rows of green lamellae on the ventral side; upper leaf cells quadrate to short rectangular or hexagonal, thin- to moderately thick-walled, smooth or with simple or blunt C-shaped papillae; basal cells rectangular, thin-walled, smooth. Autoicous. Perichaetial leaves not clearly differentiated. Setae short, straight; capsules immersed or shortly exserted, subhemispheric to ovoid or shortly cylindrical; annuli none or weakly differentiated; opercula conic-rostrate, with a short beak; peristome teeth absent or rudimentary. Calyptrae cucullate or mitrate, smooth. Spores large, spherical, brownish, papillose.