曲背藓

Cynodontium virens (Hedw.) Schimp., Coroll. Bryol. Eur. 12. 1856. Leptotrichum virens (Hedw.) Mitt., J. Proc. Linn. Soc. Bot. Suppl. 1: 11. 1859. Aongstroemia bicolor C. Müll., Nuovo Giorn. Bot. Ital. n.s. 5: 170. 1898, hom. illeg. Aongstroemia curvicaulis C. Müll., Nuovo Giorn. Bot. Ital. n.s. 5: 169. 1898. Cynodontium bicolor Paris, Index Bryol. Suppl. 111. 1900. Oncophorus bicolor (Paris) Broth., Nat. Pflanzenfam. 1(3): 319. 1901. Oncophorus curvicaulis (C. Müll.) Broth., Nat. Pflanzenfam. 1(3): 319. 1901.

Plants medium-sized to rather large, up to 3.5 cm high, green to yellowish brown above, blackish brown below, usually in dense tufts. Stems erect or ascending, simple or branched, radiculose at base; rounded in transverse section. Leaves up to 4.5 mm long, lanceolate from a broadly ovate, erect, not clearly clasping base, shoulder indistinct, gradually narrowed to a short acumen, usually keeled above, folded or slightly crispate when dry, erect-spreading or somewhat squarrose when moist, margins sometimes recurved in the lower half, plane and serrulate above; costa narrow and slender, percurrent to shortly excurrent, prominent or mammillose at back above; upper cells quadrate to rounded-quadrate, thick-walled, usually bulging; median cells short-rectangular, thick-walled; basal cells rectangular to linear-rectangular near the costa, 20–30 µm × 13–18 µm, thick-walled; alar cells not differentiated. Autoicous. Perichaetial leaves similar to the upper stem leaves, but with longer and more sheathing bases. Setae stout, elongate, up to 1.2(–2.3) cm long, yellowish brown; capsules short-cylindric, ca. 2.1 mm × 0.8 mm, brownish, smooth or somewhat furrowed when dry and empty; annuli none; peristome teeth reddish brown, ca. 5 mm long, inserted at the mouth. Spores 16–20 µm in diameter, smooth.

Syntypes. Sweden and Finland.

Chinese specimens examined: HEBEI: Xing-long Co., J.-X. Ji 1284 (IFSBH). SHAANXI: Taibai Shan (Mt.), S.-E. Liu 4289 (IFSBH). SICHUAN: Hong-yuan Co., Redfearn 35168 (MO); Mu-li Co., C. Gao 20913 (IFSBH); Nan-ping Co., S. He 30334 (MO, PE); Ruo-er-gai Co., S. He 30820 (MO, PE). XIZANG: Ya-dong Co., M. Zang 616 (IFSBH, KUN).

Habitat: on rocks or rotten wood; Distribution: China, Korea, Japan, Russia, Europe, and North America.

Illustrations: C. Gao (ed.) 1994 (Pl. 98, figs. 12–15).