Weissia microstoma (Hedw.) C. Müll., Syn. Musc. Frond. 1: 660. 1849, hom. illeg. Gymnostomum microstomum Hedw., Sp. Musc. Frond. 33. 1801. Type. Europe. Weissia hedwigii C. Crum, Bryologist 74: 169. 1971. Hymenostomum microstomum (Hedw.) R. Brown. in Nees & Hornsch., Bryol. Germ. 1: 196. 1823.

Plants small, 2–4 mm high, in dense tufts. Stems erect, simple, densely foliate. Leaves often crowded at stem tips, crisped when dry, spreading when moist, lanceolate, somewhat broad, slightly sheathing at base, upper lamina often channeled, gradually acuminate at apex; margins strongly incurved above the leaf base, entire or crenulate by projecting papillae; costa rather stout, percurrent; upper leaf cells small, rounded hexagonal, evenly thick-walled, densely papillose; basal cells sharply differentiated, rectangular, smooth. Dioicous. Setae 4–6 mm long; capsules slightly inclined, oblong-ovoid, the mouth of the capsules narrowed, closed by an imperfect membrane; peristome none; opercula conic-rostrate, with an oblique beak.

Type. Europe.

Chinese specimen examined: HUNAN: Liu-yang River, Handel-Mazzetti 11645 (H).

Habitat: on rocks in shade or thin soil over rocks; Distribution: China, widespread in Asia, Russia, Europe, northern Africa, and North America.

Illustrations: C. Gao (ed.) 1996 (Pl. 54, figs. 16–21, as Weissia microstoma).