Oreas martiana (Hopp. & Hornsch.) Brid., Bryol. Univ. 1: 383. 1826; Weissia martiana Hopp. & Hornsch. in Hook., Musc. Exot. 2: 104. 1819.
Oncophorus martiana (Hopp. & Hornsch.) Lindb. in Paris, Index Bryol. 866. 1897.
Oreas martii Kindb., Eur. N. Amer. Bryin. 2: 211. 1897.
Plants perennial, minute, 2–3 mm high, in dense compact tufts. Stems erect, branched, because of annual new-growth, densely leaved, usually radiculose within the compact tufts; triangular in transverse section. Leaves lanceolate from a narrowly oblong-ovate, erect, somewhat sheathing base, gradually narrowed to a subulate, pointed apex, crispate when dry, erect-spreading and involute when moist; margins plane or somewhat recurved, entire or serrulate only at the apex, usually bistratose; costa narrow, percurrent to shortly excurrent, smooth at back, dorsal stereid band poorly developed; upper cells smooth, rounded quadrate, but the apical cells elongate; basal cells rectangular, becoming longer near the costa, shorter close to the margins; alar cells not clearly differentiated. Autoicous. Perichaetial leaves enlarged, sheathing at base. Setae ca. 5 mm long, erect or curved when dry, cygneous when moist, yellowish; capsules ovoid to pear-shaped, with a very short neck, inclined, clearly ribbed when dry and empty, urns 1.1–2.0 mm × 0.7 mm; opercula obliquely short-rostrate; annuli poorly developed, 1–2 rows of cells, usually persistent; peristome teeth 16, reddish brown, triangular, inserted below the mouth, undivided or only perforate above, vertically striate below. Calyptrae cucullate, smooth at base. Spores brownish, 20–23 µm in diameter, warty to coarsely papillose.
Type. Austria: Tyrolean Alps, D. Hornschuch s.n. 1817.
Chinese specimens examined: SHAANXI: Taibai Shan (Mt.), Z.-P. Wei 6234 (IFSBH). SICHUAN: Li Co., Redfearn et al. 34943c (MO); Mu-li Co., C. Gao 7987 (IFSBH); Yen-yuen Co., Handel-Mazzetti 3180 (H, MO).
Habitat: on rocks or soil over rocks; Distribution: China, India, Japan, Caucasus, Europe, Greenland, and North America (Alaska).
Illustrations: C. Gao (ed.) 1994 (Pl. 91, figs. 1–5).