5. Encalypta sibirica (Weinm.) Warnst., Hedwigia. 53:316. 1913; Encalypta ciliata Hedw. var. sibirica Weinm., Bull. Soc. Imp. Naturalistes. Moscou 18: 448. 1845.
Plants small to medium-sized, 1–2 cm high, yellowish green above, brownish below, in tufts. Stems simple; central strand not well developed. Leaves incurved and irregularly twisted when dry, erect-spreading when moist, 2.5–3.0 mm long, oblong to ovate-oblong, apex abruptly narrowed to a hyaline or yellowish hair-point, hair-points about 0.1 mm long, nearly smooth; margins narrowly recurved at both sides of middle and basal portion; costa excurrent, slender in upper part of leaf; upper cells irregularly rounded-quadrate, 14–16 µm wide, densely papillose, obscure; basal cells 35–64 µm x 14–16 µm, with distinctly thickened, reddish brown transverse walls, several rows of marginal cells linear, thin-walled. Autoicous. Perichaetial leaves similar to upper stem leaves. Setae erect, yellowish or yellowish brown, 0.8 mm long, twisted above when dry; capsules cylindric, yellowish, 2.5–3.0 mm long, smooth; peristome absent; annuli undifferentiated; opercula with a straight beak. Calyptrae cylindric to narrowly cylindric, golden to golden brown, covering the whole capsule, papillose throughout except fringe bases, rostrum long, erect, 0.3–0.4 length of calyptrae. Spores 30–35 µm in diameter, proximal surface with numerous radial plicae, distal surface with regulate pattern of protuberances.
Type. Russia: Siberia.
Chinese specimens examined: HEBEI: Mt. Xiao-wu-tai, Y.-Z. Zhuo s.n. VI-VII. 1934 (IFSBH). SICHUAN: Bai-ba Co., L.-H. Bai 38-102 (IFSBH). XIZANG: Jiang-zi Co., Long-lin, M. Zang 1340 (HKAS).
Habitat: on thin soil over rocks; Distribution: China, Nepal, Russia (Siberia), Mongolia, Alaska, and North America (Texas).
Encalypta sibirica is closely related to E. ciliata. It differs from the latter by the hyaline or yellowish hair-points of the leaves, the papillose calyptrae, and lack of a peristome.
Illustrations: T. Cao, Horton & C. Gao 1992 (fig. 12, 1–10).