6. Dicranum elongatum Schleich. ex Schwaegr., Sp. Musc. Frond., Suppl. 1. 1: 171. 1811.
Plants slender, elongate, 6–16 cm long, yellowish green to brownish green above, dark brown below, shiny, in dense, compact tufts. Stems erect, simple or branched, usually with many branchlets, densely tomentose below. Leaves erect, scarcely altered or tips incurved-flexuose when dry, lanceolate, 3–5 mm × 0.4–0.5 mm, gradually narrowed from an ovate base to a subtubulose, acuminate acumen, the apex acute or obtuse; margins plane, entire below, slightly serrulate at the apex; costa stout, occupying 1/5 – ¼ the leaf base width, often percurrent or very shortly excurrent, smooth at back above; upper cells irregular, rounded quadrate or short- rectangular to slightly elongate, thick-walled, smooth, scarcely porose; basal cells elongate, strongly thick-walled, porose; alar cells quadrate or hexagonal, moderately inflated, yellowish brown, unistratose, not extending to the costa. Dioicous. Male plants normal. Setae single, straight, 8–15 mm long, yellowish; capsules erect to suberect, short-cylindric, 1.5–2.0 mm long, often slightly curved, furrowed when dry; opercula long-rostrate, nearly as long as the urns; annuli compound, in 1–2 rows of large, revoluble cells; peristome teeth 2–3 divided to the middle, reddish brown. Spores 18–22 µm in diameter, minutely papillose.
Chinese specimens examined: HEBEI: Xing-long Co., J.-X. Ji 1214 (IFSBH). JILIN: An-tuo Co., C. Gao 22159, 22280 (IFSBH, MO). LIAONING: Chang-bai Shan (Mt.), Y.-L. Zhou 768 (MO). NEI MONGOL: Da Xing An Ling (Greater Khingan Mt.), P.-C. Chen & C. Gao 920 (IFSBH); Man-gui Forest Preserve, C. Gao 12781, 12822 (IFSBH). SICHUAN: Mu-li Co., C. Gao et al. 20815 (IFSBH). XINJIANG: Fu-yun Co., R.-C. Qin 1957 (MO). YUNNAN: Gong-shan Co., M.-Z. Wang 9427(a) (IFSBH, PE).
Habitat: on wet rocks or in apline tundra; Distribution: China, Japan, Russian Far East, Europe, and North America.
Illustrations: C. Gao (ed.) 1994 (Pl. 129, fig. 4); C. Gao et al. 1977 (Pl. 54, figs. 1–5).