15. Didymodon rivicolus (Broth.) Zand. in Kop., C. Gao, J.-S. Lou & Jarvinen 溪边对齿藓 xi-bian dui-chi xian
Ann. Bot. Fenn. 20: 222. 1983. Barbula rivicola Broth., Symb. Sin. 4: 41. 1929. Type. China: Yunnan, Li-jiang, Handel-Mazzetti 6838 (holotype H).
Didymodon mamillosus Dix. in C.-Y. Yang, Sci. Rep. Natl. Tsing Hua Univ., ser. B, Biol. Sci. 2: 116. 1936, nom. nud.
Plants medium-sized to rather large, to 40 mm high, yellowish green, in dense tufts. Stems erect, branched. Leaves appressed when dry, erect-spreading when moist, oblong-ovate, narrowly acute toward the apex; margins entire, revolute; costa stout, subpercurrent or ending just a few cells below the apex; upper leaf cells rounded quadrate to rounded hexagonal, thick-walled, each cell with a large papilla; basal cells irregularly rectangular, smooth, occasionally papillose. Perichaetial leaves inflated, sheathing at the base. Setae straight, ca. 1.5 cm long, reddish; capsules erect, cylindrical, yellowish brown; peristome teeth straight, linear lanceolate, irregularly divided to the middle, densely papillose; opercula conic-rostrate, with a short beak.