Plants 0.2-9 cm high, growing in dense or open turfs, generally olive-green, occasionally reddish, reddish brown or glaucous. Stems erect, branched, sometimes with basal innovations, with or without a differentiated central strand. Leaves spirally twisted, crispate or appressed when dry, from erecto-patent to squarrose when moist, 0.9-5.8 x 0.3-2.2 mm, ovate, ovate-lanceolate, lanceolate, ovate-lingulate, lingulate, lingulate-spathulate or spathulate, constricted or not at midleaf, unistratose or bistratose, sometimes tristratose in upper third; apex rounded, obtuse, acute or emarginate, sometimes tapering into hair point, dentate, cuculate, apiculate, mucronate, mucro with 17.5-105 Ám in length, hyaline or concolorous with the lamina; margins plane or recurved one third, half, or two thirds of the length of the leaf, sometimes totally, usually papillose-crenulate, sometimes smooth, unistratose, bordered or not, with border consisting of 2-5 rows of thicker-walled and less papillose cells, sometimes smooth, brown or yellowish; hair point hyaline, sometimes brown at base, red or orange coloured, smooth, weakly spinulose or strongly spinose, 0.1-4 mm; costa 60-188 Ám wide at midleaf, in transverse section with 1-4 guide cell rows and 1-9 crescent-shaped dorsal stereid rows, with or without hydroids; on the dorsal side with or without papillae; when present papillae are from simple not pedicellate to branched and pedicellate, 2.5-37.5 Ám high, ventral epidermis present, the dorsal absent; upper and mid-lamina cells quadrate, rectangular, hexagonal or rounded, thin or thick walls, 5-27.5 x 5-22.5 Ám, with 1-12 papillae per cell, bifurcate, trifurcate or branched, pedicellate or not, 2.5-22.5 Ám high, rarely smooth; juxtacostal basal cells quadrate or rectangular, 20-137.5 x 7.5-50 Ám, hyaline or chlorophyllose, with thin or thick walls, sometimes collenchymatous, smooth, forming a clearly differentiated hyaline area, up to 14-50% of leaf length, or sometimes scarcely differentiated; marginal basal cells chlorophyllose, in 3-24 columns, generally smooth. Vegetative diaspores (brood leaves) multicellular, generally present, at the stem apex or in the axils of the upper leaves, often forming a rosette there, lanceolate, elliptical or ovate, 110-500(900) x 35-300 Ám, apical hyaline cell with or without papillae, 20-100 Ám long, with or without costa, green, papillose; (costal gemmae) multicellular, generally present, on the ventral side of the costa in the upper half or third of the leaf, globular, elliptical, ovate or rounded, 25-75 x 27.5-50 Ám, sessile, green or brown, smooth; (laminar gemmae) multicellular, generally present, on the ventral side of the leaf on the lamina, globular, ovate or rounded, 25-45 x 25-37.5 Ám, sessile, green or brown, smooth. Dioicous, autoicous or synoicous. Seta erect, 0.45-3.1 cm long, spirally twisted to right above, to left below or to right throughout, reddish brown. Capsule erect, sometimes inclined, cylindrical or ovoid-cylindrical, 1.3-6 x 0.3-1.1 mm, brownish, exothecial cells quadrate, rectangular, with thin or thick walls, smooth; annulus of 1-4 rows of quadrate to rectangular cells, 12.5-17.5 Ám in width. Peristome of 32 papillose, spirally twisted teeth, 0.2-1.8 mm high; basal membrane of 3-42 rows of cells, 0.09-1.4 mm high. Operculum long conical, 1-2.7 mm high. Calyptra cucullate, long conical, 2-4.5 mm high. Spores spherical, 7.5-25 Ám in diameter, papillose. Laminal KOH colour reaction reddish or brick red.