石芽藓

Plants tiny, bulbiform, 2–3 mm high, grayish green with whitish color, in loose tufts. Stems erect, simple, rarely branched; central strand present. Leaves appressed or imbricate when dry, loosely spreading when moist, cordate to circular or broadly obovate, often deeply concave; margins broadly recurved or plane, entire except near the apex, borders not differentiated; costa thin, subpercurrent to percurrent or occasionally excurrent, ending in a hyaline awn; in cross section only dorsal stereid band present; upper leaf cells rhombic to hexagonal, usually thin-walled, or more elongate, rhomboidal near the apex, becoming thicker walled, smooth; basal cells rectangular, moderately thick-walled, smooth. Autoicous. Perichaetial leaves similar to stem leaves. Setae elongate, straight, ca. 4–6(–12) mm long, yellowish brown; capsules erect, oblong-ovoid to cylindrical, ca. 1 mm long, with a short neck; annuli none; opercula conic-rostrate, with a long, oblique beak; peristome teeth 16, erect, linear-lanceolate, not divided or irregularly divided, densely papillose. Calyptrae not seen. Spores 39–45 µm in diameter, reddish brown, densely papillose.

Type. Europe.

Chinese specimens examined: GANSU: G. N. Potanin 8a (H); He-xi Co., S.-Z. Hu 1837a (MO, PE); Qi-lian Shan (Mt.), D.-Z. Zhuo 761-50 (PE). HEBEI: Xiao-wu-tai Shan (Mt.), L.-Q. Yu s.n. (PE). LIAONING: Ben-xi Co., C. Gao 8357 (HKAS, IFSBH). XINJIANG: Bur-qin Co., S.-L. Chen 331 (PE); He-jing Co., S. He 951227 (MO); Ku-che Co., S. He 951207 (MO); Urumqi Co., S. He 951084 (MO), Whittemore et al. 4814 (MO). XIZANG: Lang Co., M. Zang 1726 (HKAS).

Habitat: on rocks in alpine regions; Distribution: China, India, Russia, Europe, and North America.

Illustrations: C. Gao (ed.) 1996 (Pl. 79, figs. 1–5).