Campylopus involutus (C. Müll.) Jaeg., Ber. Thätigk. St. Gallischen Naturwiss. Ges. 1870–71: 418. 1872. Dicranum involutum C. Müll., Bot. Zeitung (Berlin) 11: 34. 1853. Thysanomitrion involutum (C. Müll.) P. de la Varde, Rev. Bryol. 49: 41. 1922. Campylopus tenuinervis Fleisch., Musci Fl. Buitenzorg. 1: 120. 1904.

Plants small to medium-sized, up to 2(–5) cm high, yellowish brown, somewhat shiny, in dense tufts. Stems reddish, erect, simple or rarely branched, comose foliate, radiculose at base. Leaves 5–6 mm long, somewhat flexuose when dry, erect-patent when moist, lanceolate, contracted at base, gradually narrowed to a canaliculate subula, ending in a subhyaline to occasionally hyaline hairpoint; margins inflexed in the upper 2/3, serrulate in the upper 1/3; costa pale yellowish brown, occupying ca. 1/3 the leaf base width, shortly excurrent, with dorsal and ventral stereid bands, sometimes the ventral stereid band not well defined in transverse section; upper cells obliquely rectangular to rhomboidal, ca. 30 µm × 10 µm, thick-walled, sometimes with 1 row of thin-walled, rectangular cells at the margins; basal cells yellowish, moderately long-rectangular, ca. 50 µm × 15 µm, narrower toward the margins; alar cells forming well marked auricles, moderately inflated, hyaline or reddish brown. Dioicous. Setae ca. 5 mm long, straight when dry, cygneous when moist, reddish brown; capsules erect, ovoid to short-cylindric, symmetric, scabrose at base; opercula long-rostrate; annuli compound, in 2 rows of cells; peristome teeth divided to the middle or lower, reddish and not vertically striate below. Calyptrae fringed at base. Spores 8–9 µm in diameter, yellow, smooth.

Type. India: Khasia, Griffith 65.

Chinese specimens examined: FUJIAN: Sanming City, D.-K. Li 1478 (SHM); Wuyi Shan (Mt.), P.-J. Lin 2354 (IBSC). GUANGDONG: Ru-yuan Co., P.-J. Lin 577 (IBSC), Yue 73 Collecting Team 134 (IBSC); Ying-de Co., IBSC Geo. Dept. 6100 (IBSC). GUANGXI: Shang-si Co., W.-T. Toang 72760 (SYS). GUIZHOU: Jiang-kou Co., C. Gao & J.-Y. Feng 31794 (IFSBH, MO); Sui-yang Co., C. Gao & J.-Y. Feng 32787 (IFSBH). HAINAN: Bai-sha Co., Redfearn 35767a (MO); Chang-jiang Co., Redfearn 35703 (MO); Jianfengling (Mt.), C.-H. Gao 574 (SHM); Ling-shui Co., IBSC Collecting Team 2638 (IBSC). HUBEI: Ba-dong Co., L.-J. Bi 407 (HBNU). JIANGXI: Lu Shan (Mt.), C. Gao 40776 (IFSBH, MO), F.-Z. Huang & H. Sun 2(15128) (HSNU). SICHUAN: Mu-li Co., C. Gao et al. 20383 (IFSBH). YUNNAN: Da-li Co., Redfearn et al. 1134 (MO); De-hong Pref., W.-X. Xu 49 (YUKU); Jing-hong Co., Redfearn 34288 (MO); Kunming City, W.-X. Xu 135 (YUKU); Meng-hai Co., Magill et al. 7988 (MO), Redfearn 34171 (MO); Meng-la Co., Magill et al. 7698 (MO); Song-ming Co., Redfearn et al. 1833 (MO); Tian-chong Co., X.-J. Li 428 (KUN); Xishuangbanna, X.-J. Li 2470 (KUN), L. Zhang 869 (MO).

Habitat: on bases of trees and soil; Distribution: China, Nepal, India, Sri Lanka, Myanmar, Thailand, Vietnam, Indonesia, and the Philippines.

Illustrations: Pl. 25, figs. 6–11.