角齿藓

Didymodon purpureus (Hedw.) Hook. & Tayl., Musc. Brit. 65. 20. 1818. ? Ceratodon sinensis C. Müll., Nuovo Giorn. Bot. Ital., n.s. 3: 104. 1896. Type. China: Shaanxi (Schen-si), Giraldi s.n., July 1894 [holotype B, probably destroyed]. Ceratodon purpureus var. rotundifolius Berggr., Kongl. Svenska Vetensk. Acad. Handl. 13(7): 44. 1875.

Plants small to medium-sized, (5–)8–20(–30) mm high, dirty green or yellowish green, in dense tufts. Stems erect, simple or sparsely branched, radiculose at base. Leaves slightly appressed or contorted when dry, erect-patent when moist, lanceolate, 1.0–2.1 mm long, gradually acuminate; margins strongly reflexed or revolute, notched or irregularly serrulate near the apex; costa stout, percurrent to shortly excurrent; upper and median leaf cells quadrate, 7–10 µm wide, slightly thick-walled, smooth; basal leaf cells short-rectangular, 13–20 µm × 7–10 µm, rather thin-walled. Dioicous. Perichaetial leaves strongly convolute-sheathing at base, shortly acuminate at apex. Setae straight, 1.0–2.0 cm long, reddish brown; capsules cylindric, strongly inclined to horizontal, reddish brown, 2–3 times as long as wide, 1.0–2.0 mm × 0.5–0.7 mm, deeply furrowed when dry, somewhat strumose at base; opercula conic-rostrate; annuli differentiated, in 2–3 rows of thick-walled cells; peristome teeth lanceolate, divided nearly to the base, bordered with a hyaline band, finely papillose, basal membrane low. Spores 11–13 µm in diameter, yellowish, smooth or nearly so.

Syntypes. Europe: “Bryum tenue stellatum setis purpureus, Dill. Musc. t. 49, f. 51, 386; Mnium purpureum, Linn. Spec. ed. 11, 1575. 6.”.

Chinese specimens examined: ANHUI: Jin-zhai Co., Z.-M. Zeng T0291 (MO). HEBEI: Wuling Shan (Mt.), J.-M. Liu 112 (IFSBH). HEILONGJIANG: Dailing, C. Gao 131 (IFSBH); Ganhe, C. Gao 12931 (IFSBH); Wudalianchi, C. Gao 13251 (IFSBH); Xinlin, C. Gao 13110 (IFSBH). HUBEI: Shennongjia Forest Distr., Bartholomew et al. 523e (MO). JIANGSU: Zhen-ze Co., R.-L. Hu 130 (HSNU). JILIN: Changbai Shan (Mt.), C. Gao 1044 (IFSBH); Longtan Shan (Mt.), C. Gao 1877 (IFSBH). LIAONING: Kuan-dian Co., T. Cao & S.-Z. Wang 38834 (IFSBH), B. Tan 93659 (MO); Heng-ren Co., T. Cao & J.-Y. Feng s.n. Sept. 1986 (IFSBH); Qian Shan (Mt.), C. Gao 1915 (IFSBH). NEI MONGOL: Mangui, C. Gao 12864 (IFSBH); Wufeng Shan (Mt.), P.-C. Chen & C. Gao 847 (IFSBH). SHAANXI: Taibai Shan (Mt.), Z.-P. Wei 5641, 6246 (IFSBH). SICHUAN: Liang Shan (Mt.), G.-C. Zhang & T. Cao 21416, 21489 (IFSBH). XINJIANG: He-jiang Co., J.-C. Zhao 953312 (MO); Tian Shan (Mt.), C.-F. Zhao 2524 (IFSBH). XIZANG: Cha-yu Co., S.-G. Wu 1072E (PE); Donggala, M. Zang 345 (KUN); Lang-xian Co., M. Zang 1902 (KUN); Shejila, S.-K. Chen 417 (PE). YUNNAN: Gongshan (Mt.), M.-Z. Wang 9963B (PE).

Habitat: often on soil or on the base of rotten trees in open fields; Distribution: nearly worldwide.

Illustrations: C. Gao 1994 (Pl. 38, figs. 1–7).