1. Orthodicranum flagellare (Hedw.) Loeske, Stud. Morph. Syst. Laubm. 85. 1910; Dicranum flagellare Hedw., Sp. Musc. Frond. 130. 1801.
Plants usually 1–4 cm high, green to brownish green, in compact tufts. Stems erect, tomentose below, usually producing clusters of stout, stiff brood branchlets in the axils of upper leaves. Leaves up to 3 mm long, crispate when dry, erect-spreading to somewhat falcate-secund when moist, linear- to oblong-lanceolate from an erect base, distinctly subtubulose above, blunt or narrowly obtuse at the apex; margins involute and serrulate above, entire below; costa percurrent to shortly excurrent; upper cells quadrate to irregularly rhombic, thick-walled, smooth or slightly roughened, not mammillose on the dorsal surface; lower cells elongate, rectangular, rather thick-walled, sometimes porose; alar cells differentiated, often brownish, in a small group. Setae straight, elongate, (0.5–)1.0–1.8 (–2.5) cm long, yellowish brown; capsules erect, cylindric, straight or nearly so, slightly contracted at base, with a long apophysis, irregularly furrowed when dry; annuli in 2 rows of small cells; peristome teeth linear-lanceolate, divided or perforate to the middle, reddish brown, sometimes with prostome. Spores 16–22 µm in diameter.
Chinese specimens examined: HEILONGJIANG: Da Xing An Ling (Greater Khingan Mt.), C. Gao 12979, 13134 (IFSBH); Hai-lin Co., C. Gao & G.-C. Zhang 9156 (IFSBH); Wu-ying Pref., C. Gao 373 (IFSBH); Xiao Xing An Ling (Lesser Khingan Mt.), C. Gao 8 (IFSBH). HUBEI: Shen-nong-jia Pref., 1980 Sino-Amer. Exped. No. 1891b (MO). JILIN: Chang-bai Co., C. Gao 7346 (IFSBH). SICHUAN: Wo-long Co., Q.-Z. Zheng 105b (MO). YUNNAN: Da-li Co., Croat 77492 (MO).
Habitat: on bases of trees, rarely on rocks; Distribution: China, Korea, Japan, Russian Far East, Europe, and North America.
Illustrations: C. Gao (ed.) 1994 (Pl. 107, figs. 6–11).