Weissia crispa (Hedw.) Mitt., Ann. Mag. Nat. Hist., ser. 2, 8: 316. 1851, hom. illeg. Astomum crispum (Hedw.) Hampe, Flora 20, 285. 1837. Phascum crispum Hedw., Sp. Musc. Frond. 21. 1801. Type. Britain: Mougeot & Nestler 703. Astomum macrophyllum (Par. & Broth.) G. Roth, Aussereur. Laubm. 185. 1911. Systegium macrophyllum Par. & Broth., Rev. Bryol. 35: 125. 1908. Astomum tonkinense (Par. & Broth.) Broth., Nat. Pflanzenfam. I(3): 1189. 1900. Systegium tonkinense Par. & Broth., Rev. Bryol. 33: 54. 1906.

Plants small, to 5 mm high, often dark green, in loose tufts. Stems erect, usually simple; central strand weakly developed. Leaves often crowded at stem tips, strongly crisped when dry, spreading when moist, narrowly lanceolate to oblong-lanceolate, sheathing at base, upper lamina often channeled, acuminate at apex; margins strongly incurved above the leaf base, entire or crenulate by projecting papillae; costa rather stout, shortly excurrent, ending in sharply mucronate tips; upper leaf cells rounded-hexagonal, evenly thick-walled, papillose, with bifid or C-shaped papillae; basal cells sharply differentiated, rectangular, forming a V-shaped leaf base, moderately thick-walled, smooth, hyaline. Autoicous. Setae very short, ca. 1 mm long; capsules erect, oblong-ovoid, immersed; annuli none; opercula not differentiated; peristome none.

Chinese specimens examined: ANHUI: Da-bie Shan (Mt.), K.-H. Tsai 1966 (HKAS); Wu-hu Co., P.-C. Chen 6402 (PE). FUJIAN: Fu-zhou City, Gu Shan (Mt.), M. Zang 894 (HKAS); Wuyi Shan (Mt.), P.-C. Chen 73 (PE). HAINAN: Jian-feng-ling (Mt.), P.-C. Chen 18 (PE). HEILONGJIANG: Da-hai-lin, C. Gao 9120 (HKAS, IFSBH); Ning-an Co., C. Gao 9080 (HKAS, IFSBH). HENAN: Kai-feng City, D.-K. Li 6461 (PE). HUNAN: Da-rong City, D.-K. Li 17915 (HKAS, SHM); Sang-zhi Co., D.-K. Li 18334 (HKAS, SHM). JIANGSU: Nan-jing City, M. Zang 631 (HKAS); Nan-tong City, X.-S. He 15804 (HKAS); Wu Co., R.-L. Hu 17 (HSNU); Yi-xing Co., D.-K. Li 276 (HKAS, SHM). JILIN: Ji-an Co., C. Gao 7869 (HKAS, IFSBH). LIAONING: Kuan-dian Co., C. Gao 8510 (HKAS, IFSBH). NINGXIA: Niu-shou Shan (Mt.), S.-W. Liu 7e (PE). SHANDONG: Kun-yu Shan (MT.), C. Gao 18559 (HKAS, IFSBH). SHANGHAI: X.-M. Xu 620 (HKAS). SHANXI: Xi-yang Co., Q. Li 800 (HKAS, IFSBH). SICHUAN: Cheng-du City, J.-L. Yang M17 (PE); Chong-qing City, D.-K. Li 16107 (HKAS, SHM); Xiang-cheng Co., X.-J. Li 813015 (HKAS). TAIWAN: Tai-bei Co., Koponen 16683 (H, HKAS). XIZANG: Lang Co., M. Zang 1690 (HKAS); Rigeze City, Z.-X. Tan 34a (HKAS); Ya-dong Co., Y.-C. Yang 1c (HKAS). YUNNAN: Qiu-bei Co., X.-J. Li 244 (HKAS); Yi-liang Co., X.-J. Li 4540 (HKAS); Zhong-dian Co., X.-J. Li 811484 (HKAS). ZHEJIANG: Lin-an Co., H.-C. Tan 6130 (HKAS, SHM); Sheng-si Co., D.-K. Li 3855 (HKAS, SHM).

Habitat: on forest ground, rocks or boulders; also on soil walls or thin soil over rocks in shade; Distribution: China, Japan, India, Pakistan, Russia, Europe, northern Africa, and North America.

Illustrations: C. Gao (ed.) 1996 (Pl. 54, figs. 7–10, as Weissia crispa).