Campylopus fragilis ssp. fragilis (Brid.) Bruch & Schimp. in B. S. G., Bryol. Eur. 1: 164 (fasc. 41, Mon. 4). 1847; Dicranum fragile Brid., J. Bot. (Schrader) 1800(2): 296. 1801.
Campylopus akagiensis Broth. & Yas., Öfvers. Förh. Finska Vetensk.-Soc. 62A(9): 3. 1921.
Plants minute- to medium-sized, 5–30 mm high, comose foliate, green to yellowish green, in compact tufts. Stems erect, simple or branched, radiculose at base, often with numerous boomerang-shaped brood leaves in the axils of the upper leaves. Leaves appressed or slightly flexuose when dry, erect or erect-patent when moist, rather rigid at the tips, 3–6 mm long, lanceolate from a broad, ovate base, gradually narrowed to a finely subulate acumen; margins plane or slightly involute, entire or serrulate only at the apex; costa widest at about midleaf, gradually narrowed toward leaf base, occupying 1/3 – 2/3 the leaf base width, shortly excurrent in a non-hyaline tip, lightly ridged at back in the upper part, with only dorsal stereid band in transverse section; upper cells quadrate to short-rectangular; basal cells rectangular, rather thin-walled; alar cells not clearly differentiated, only somewhat inflated, hyaline. Dioicous. Setae straight, elongate, yellowish to yellowish brown; capsules erect or slightly curved; peristome teeth dicranoid; opercula shortly rostrate. Calyptrae fringed at base. Spores 9–20 µm in diameter.
Type. Germany: Erlangen, Hoffmann. s.n.
Chinese specimens examined: GUIZHOU: Guiyang City, C. Gao 40233 (IFSBH, MO); Sui-yang Co., C. Gao & J.-Y. Feng 33166 (IFSBH, MO). HAINAN: Bawanglinag (Mt.), P.-Z. Zheng 3 (IBSC). SICHUAN: Song-pan Co., Allen 7112 (MO). TAIWAN: Hwa-lien Co., C.-C. Chuang 5708 (MO); Tai-tung Co., M.-J. Lai 9571 (MO). YUNNAN: Gong-shan Co., M.-Z. Wang 9265(a) (PE), M. Zang 20d (KUN); Jing-dong Co., J.-K. Zhang 1187 (YUKU).
Habitat: on rotten wood, wet soil, or rocks; Distribution: China, Korea, Japan, Russian Far East, Europe, North and Central America.
Illustrations: C. Gao (ed.) 1994 (72, figs. 1–7).