4. Hydrogonium gangeticum (C. Müll.) P.-C. Chen, Hedwigia. 80:237. 1941; Barbula gangetica C. Müll., Linnaea 37: 177. 1872.
Plants grayish green, in dense tufts. Leaves contorted when dry, erect-spreading when moist, triangular-lanceolate or ligulate, blunt to rounded-obtuse at the apex; margins entire, weakly revolute in the lower half; costa stout, percurrent; upper leaf cells irregularly hexagonal, thin-walled, papillose; basal cells slightly larger, smooth, hyaline. Gemmae numerous, multicellular, forked or stellate. Setae straight, slender; capsules erect, ovoid-cylindrical; peristome teeth linear, twisted; opercula long-rostrate.
Type. Bangladesh: Kurz 1796.
Chinese specimens examined: SICHUAN: Du-kou City, Jing-sha-jiang (River), L.-S. Want 83–97 (HKAS). XIZANG: Mo-tuo Co., Y.-G. Su 3795 (HKAS). YUNNAN: Meng-la Co., L. Zhang 413 (HKAS).
Habitat: on rocks or thin soil over rocks near rivers or streams; Distribution: China, Bangladesh, and India.
Illustrations: Pl. 124, figs. 1–3.