Plants very small, only to 2.0 mm high, yellow, in compact tufts. Stems erect, simple. Leaves imbricate and concave; oblong-ovate and obtuse, gradually becoming larger toward the stem apex on sterile plants; margins entire; costa strong, percurrent or excurrent, not filling subula; cells smooth, rectangular at base, short and qudarate above. Autoicous. Perichaetial leaves sheathing at base, abruptly narrowed to a stout, short subula. Setae elongate, straight, twisted or curved when dry, almost straight when moist; capsules ovoid to oblong-ovoid, somewhat asymmetric. Other features are the same as those described in the generic description.

Type. Sweden: Swartz s.n. 1808.

Chinese specimen examined: SICHUAN: Liang Shan (Mt.), G.-C. Zhang & T. Cao 21495 (IFSBH).

Habitat: on calcareous rocks in high mountains, often mixed with other mosses; Distribution: China, Ukraine, Europe, Greenland, and North America.

Illustrations: C. Gao (ed.) 1994 (Pl. 45, figs. 1–10).