扭叶牛毛藓

Ditrichum microcarpum Broth. in Handel-Mazzetti, Symb. Sin. 4: 12. 1929. Type. China: Yunnan, Handel-Mazzetti 6264 (holotype H). Ditrichum setschwanicum Broth. in Handel-Mazzetti, Symb. Sin. 4: 12. 1929. Type. China: Sichuan, Yen-yuan Co., Handel-Mazzetti 2859 (holotype H; isotype MO). Ditrichum tortile (Schrad.) Brockm., Arch. Ver. Freund. Naturg. Mecklenburg 23: 74. 1870. Ditrichum pusillum var. tortile (Schrad.) I. Hag., Kongel. Norske Vidensk., Selsk. Skr. 1910 (1): 50. 1910. Trichostomum tortile Schrad., Bot. Zeitung (Regensburg) 1: 74. 1802.

Plants small, 0.7–1.0 cm high, yellowish green or brown, in loose tufts. Stems erect, simple or sparsely branched. Leaves appressed when dry, erect-patent when moist, lanceolate, 2.0–2.3 mm long, gradually narrowed from an ovate base to a slender acumen; margins reflexed or revolute below, plane above, entire throughout; costa stout, shortly excurrent; cells rectangular, thin-walled, 10–20 µm × 3–5 µm at the shoulder, 13–26 µm × 5–10 µm at the margins, the upper ones shorter. Dioicous. Setae straight, 5.0–7.0 mm long, yellowish brown, sometimes twisted above; capsules erect, oblong-ovoid, symmetric, ca. 2 mm long, smooth when dry; opercula short conic-rostrate; annuli in 2 rows of large and thick-walled cells; peristome teeth linear, ca. 0.2 mm long, divided nearly to the base, papillose, whitish yellow above, yellowish brown below. Spores 16–18 µm in diameter, yellowish brown, irregularly papillose.

Type. Austria.

Chinese specimens examined: GUANGDONG: Chao-an Co., P.-J. Lin 3388 (IBSC). HAINAN: Diaoluo Shan (Mt.), C. Gao 2768 (IFSBH). HUNAN: Shuang-zhi Co., D.-K. Li 18449 (SHM). JILIN: Changbai Shan (Mt.), C. Gao 7183, 7477 (IFSBH). SICHUAN: Yan-yuan Co., see the type information of D. setschwanicum cited above. XIZANG: Mo-tuo Co., Y.-G. Su 4467 (KUN). YUNNAN: Beyendjing, between Tschuhsiung and Yungbei, see the type information of D. microcarpum cited above.

Habitat: on wet soil or rocks; Distribution: China, Russian Far East, Europe, North America, and Africa.

Illustrations: C. Gao (ed.) 1994 (Pl. 32, figs. 1–6).