Didymodon tenuirostris (Hook. f. & Tayl.) Wils., Hooker's J. Bot. Kew Gard. Misc. 3: 378. 1841. Trichostomum cuspidatum (Dozy & Molk.) Dozy & Molk., Bryol. Jav. 1: 96, f. 78. 1859. Oxystegus cuspidatus (Dozy & Molk.) P.-C. Chen, Hedwigia 80: 143. 1941. Didymodon cuspidatus Dozy & Molk. in Zoll., Syst. Verz. 31. 1854. Trichostomum cylindricum (Brid.) C. Müll., Syn. Musc. Frond. 1: 586. 1849, hom. illeg. Didymodon cylindricus (Brid.) Bruch & Schimp., Bryol. Eur. 2: 139. (fasc. 29–30. Monogr. 5. 3). 1846, hom. illeg. Oxystegus cylindricus (Brid.) Hilp., Beih. Bot. Centralbl. 50(2): 620. 1933. Tortella cylindrica (Brid.) Loeske, Stud. Morph. Syst. Laubm. 97. 1910. Weissia cylindrica Bruch. ex Brid., Bryol. Univ. 1: 806. 1827. Trichostomum cylindricum var. denticuspis Broth., Symb. Sin. 4: 33. 1929. Type. China: Yunnan, between Djinscha-djiang and Mekong, Handel-Mazzetti 7882 (holotype H). Trichostomum leptotortuosum (C. Müll.) Broth., Nat. Pflanzenfam. I(3): 394. 1902. Barbula leptotortuosa C. Müll., Nuovo Giorn. Bot. Ital., n. ser. 5: 179. 1898. Type. China: Shaanxi (Schen-si), Tui-kio-san, 20 X 1896, P. J. Giraldi 1816. Trichostomum parvulum Broth., Akad. Wiss. Wien Sitzungsber., Math.-Naturwiss. Kl., Abt. 1, 133: 564. 1924. Type. China: Yunnan, Yun-ling, Handel-Mazzetti 3132 (holotype H).

Plants small to medium-sized, 10–30(–40) mm high, yellowish green to light brown, in dense tufts. Stems erect, usually irregularly branched. Leaves strongly crisped when dry, erect-spreading or weakly reflexed when moist, linear-lanceolate, acuminate or setaceous at apex, weakly sheathing at base; margins usually undulate and wavy, crenulate by projecting papillae; costa slender, percurrent; upper leaf cells quadrate to hexagonal, rather thin-walled, green and obscure, each cell with several large, circular papillae on both surfaces; basal cells slightly elongate, rectangular, smooth. Sporophytes not seen.

Type. Europe.

Chinese specimens examined: ANHUI: Huang Shan (Mt.), D.-K. Li 2174 (HKAS, SHM); Jin-zhai Co., Z.-M. Zeng T0247 (MO). BEIJING: Ju-rong-guan (Great Wall), P.-C. Chen 10 (PE). FUJIAN: Wuyi Shan (Mt.), D.-K. Li 9176 (SHM). GUANGDONG: Ding-hu Shan (Mt.), P.-J. Lin s.n. (IBSC). GUANGXI: Long-sheng Co., P.-C. Wu 1021b (PE); Rong-shui Co., X.-L. He 373 (PE); Tian-lin Co., C. Gao 2334 (HKAS, IFSBH). GUIZHOU: Fan-jing Shan (Mt.), B.-G. Zhong 184 (PE). HAINAN: Diao-luo Shan (Mt.), C. Gao 2956 (HKAS, IFSBH). HEBEI: Wei Co., H.-B. Cui 7a (PE). HEILONGJIANG: Da-hai-lin, C. Gao 9261 (HKAS, IFSBH); Wu-ying Distr., Vitt 34904 (ALTA, MO). HENAN: Ji-gong Shan (Mt.), H.-J. Yu 29 (HKAS). HUBEI: Sheng-nong-jia (Mt.), P.-C. Wu 434b (MO, PE). HUNAN: Da-rong Co., D.-K. Li 18403 (HKAS, SHM); Sang-zhi Co., D.-K. Li 18519 (HKAS, SHM). JIANGSU: Nan-jing City, D.-X. Ye 4 (PE); Su-zhou City, S.-L. Li 17 (PE). JIANGXI: Jing-gang Shan (Mt.), D.-K. Li 16839 (HKAS, SHM). JILIN: An-tu Co., C. Gao 61179 (HKAS, IFSBH); Chang-bai Shan (Mt.), C. Gao 1197 (HKAS, IFSBH); Jiao-he City, Lao-ye-ling (Mt.), C. Gao 1591 (IFSBH). LIAONING: Qian Shan (Mt.), C. Gao 1222 (HKAS, IFSBH). NEI MONGOL: Da-xing-an-ling (Greater Khingan), C. Gao 790 (IFSBH). SHAANXI: Hu Co., Z.-P. Wei 4543 (HKAS, WUG); Tai-bai Shan (Mt.), Q. Huang 2321 (PE). SHANDONG: Tai Shan (Mt.), C. Gao 34090 (IFSBH). SICHUAN: Ba-tang Co., S. He 31400 (MO); Dao-cheng Co., S. He 31659a (MO); De-rong Co., X.-J. Li 812887 (HKAS); Ma-er-kang Co., S. He 31178 (MO); Nan-ping Co., S.-Y. Zeng 231 (HKAS); Wen-chuan Co., J.-X. Luo 3656 (PE); Xiang-cheng Co., S. He 31760a (MO). TAIWAN: A-li Shan (Mt.), Iwatsuki & Sharp 2115 (NICH); Chia-yi Co., Koponen 17136 (H); Hsin-chu Co., Shevock 14410 (MO); Miao-li Co., C.-K. Wang 0524 (NICH), Shevock 14353 (MO); Tai-chong Co., Koponen 17750 (H, HKAS). XINJIANG: Urumqi Co., S. He 951069 (MO). XIZANG: Lang Co., M. Zang 1848 (HKAS); Lin-zhi Co., Y.-G. Su 2783 (HKAS); Mi-lin Co., S.-K. Chen 184 (HKAS); Mo-tuo Co., Y.-G. Su 1160 (HKAS); Mt. Everest, X.-G. Wang 85 (MO, PE); Ya-dong Co., S.-K. Chen 4978a (HKAS). YUNNAN: An-ning Co., Koponen 37895 (H, HKAS); Cang-yuan Co., S.-Y. Zeng 801832 (HKAS); Da-li Co., Handel-Mazzetti 6475 (H); De-qin Co., X.-J. Li 43091 (HKAS); Gong-shan Co., Q.-W. Wang 6345 (PE); Jing-dong Co., J.-K. Zhang 889 (HYUB); Kun-ming City, Koponen 37356 (H, HKAS); Li-jiang Co., X.-J. Li 85453 (HKAS); Lv-chun Co., M. Zang 709 (HKAS); Meng-hai Co., Redfearn et al. 34173 (MO); Meng-lian Co., X.-J. Li 2731 (HKAS); Meng-zi Co., M. Zang 15215 (HKAS); Qiu-bei Co., X.-J. Li 223 (HKAS); Rui-li Co., X.-J. Li 134 (HKAS); Teng-chong Co., X.-J. Li 80321 (HKAS); Zhong-dian Co., X.-J. Li 811622 (HKAS). ZHEJIANG: Sui-chang Co., Jiu-long Shan (Mt.), Z.-L. Liu 31 (HSNU); Wen-zhou City, D.-K. Li 8051 (HKAS, SHM); western Tian-mu Shan (Mt.), M. Zang 216 (HKAS).

Habitat: on soil, forest ground, or rocks in shade; also on tree bases; Distribution: China, India, Japan, Russia, Europe, Africa, North and South America.

Illustrations: C. Gao (ed.) 1996 (Pl. 52, figs. 1–7, as Oxystegus cuspidatus and O. cylindricus).