Fissidens areolatus Griff., Calcutta J. Nat. Hist. 2: 506. 1842. Fissidens polypodioides var. areolatus (Griff.) Wils., Hooker’s J. Bot. & Kew Gard. Misc. 9: 294. 1857.

Plants large, green, yellowish green to brownish, in lax tufts. Leafy stems 27–72 mm long, 6.0–6.8 mm wide, simple or branched; central strand well developed. Axillary hyaline nodules not developed. Leaves in 23–58 pairs, densely arranged except the lowermost ones, which are much smaller and more or less loosely arranged; middle to upper leaves oblong-lanceolate, 3.6–4.1 mm × 1.0–1.1 mm, mostly mucronate, occasionally broadly acute; base of dorsal laminae rounded; vaginant laminae 1/2 the length of the leaf, equal or slightly unequal; costa stout, usually ending a few cells below leaf apex, rarely percurrent; coarsely serrulate near apex, slightly serrulate throughout the rest of margin; cells of apical and dorsal laminae quadrate to hexagonal, 11–21 µm long, smooth to slightly mammillose, well demarcated, moderately thick-walled; cells of vaginant laminae similar to those of apical and dorsal laminae, but larger, with thicker walls, especially towards the base near costa. Dioicous. Female inflorescences usually terminal on short lateral branches. Archegonia 340–596 µ m long. Perichaetial leaves differentiated, shorter and narrower than stem leaves, 4.6–5.6 mm long, 0.4–0.6 mm wide, acute, base of dorsal laminae wedge-shaped, cells of vaginant laminae much longer than those of apical and dorsal laminae.

Type. Jamaica, Swartz s.n.

Chinese specimens examined: FUJIAN: Wuyi Shan (Mt.), P.-J. Lin 2403 (IBSC, SYS). GUANGDONG: Ding-hu Shan (Mt.), Redfearn et al. 34397 (MO); Feng-kai Co., L. Sun & J.-L. Zhang 85 (SYS); Long-men Co., Z.-H. Li 51 (SYS). GUANGXI: Tian-lin Co., 1974 Team 19 (IBSC, SYS). GUIZHOU: Fan-jing Shan (Mt.), C. Gao & J.-Y. Feng 31243 (IFSBH, SYS). HAINAN: Jian-feng-ling (Mt.), P.-C. Chen 743b (PE, SYS). HUNAN: Da-yong Co., Zhang-jia-jie, D.-K. Li 18124 (SHM, SYS); Yi-zhang Co., 1974 Team 955 (IBSC, SYS). JIANGXI: Jing-gang Shan (Mt.), D.-K. Li 16734 (SHM, SYS). SICHUAN: Omei Shan (Mt.), M. Zang 802498 (H, HKAS); Yan-bian Co., M.-Z. Wang 20795 (PE, SYS). TAIWAN: Chia-yi Co., M.-J. Lai 10186 (H, MO); Nan-tou Co., Koponen 17527 (H); Ping-tung Co., S.-H. Lin 5293c (NICH, TUNG). XIZANG: Mo-tuo Co., Y.-G. Su 4506 (HKAS, NICH). YUNNAN: Gong-shan Co., M.-Z. Wang 11134 (PE, SYS); Jing-dong Co., J.-K. Zhang 1296 (IFSBH, SYS); Jing-hong Co., Redfearn et al. 34283 (MO); Teng-chong Co., X.-J. Li 80385 (H, HKAS); Yang-bi Co., Redfearn et al. 767a (MO); Ying-jiang Co., J.-X. Luo & M.-Z. Wang 812982a (PE, SYS); Zheng-kang Co., Q.-W. Wang 8037 (PE, SYS).

Habitat: on soil, boulders, or cliffs; Distribution: China, Japan, India, Nepal, Myanmar, Thailand, Vietnam, Malaysia, Indonesia, the Philippines, New Guinea, the West Indies, and throughout the Americas.

This species is characterized by the large plants ranging from 27 to 72 mm high, the mucronate to broadly acute and coarsely serrate leaf apex, the costa usually ending a few cells below the leaf apex, the smooth to slightly mammillate, well demarcated cells of the apical and dorsal laminae, ranging from 10.5 to 21.0 µm long, the well differentiated perichaetial leaves, and the longer archegonia.

Illustrations: Z.-H. Li 1985 (Fig. 20, a–h, as Fissidens areolatus).