Plants dark green, sometimes forked, in low dull tufts and cushions. Stems evident; rhizoids glossy dark red. Leaves essentially monomorphic, vegetative leaves grading into gemmiferous leaves, contorted-curled when dry, bases often conspicuous, with metallic gloss, erect-spreading and straight when wet, oblong-lanceolate to acuminate above broader base, to 4–5 mm long; axillary hairs inconspicuous; costa percurrent, in gemmiferous leaves protruding beyond expanded portion of upper laminae, with narrow wings of laminae revolute along its flanks; cells of upper laminae small, obscure, isodiametric, nearly smooth to papillose abaxially, bulging to mammillose-papillose adaxially; margins thickened and toothed distally; teniolae conspicuous; cancellinae typically acute distally, their distal cells plane, sharply and evenly demarcated from adjacent green cells of upper laminae; gemmae common, borne on adaxial tips of costa, gemma receptacle sometimes evident. Sporophytes not seen.

Type. Africa: Afzelius s.n. (holotype BM–herb. Hampe).

Chinese specimens examined: GUANGDONG: Zhao-qing Co., P.-J. Lin et al. 176 (IBSC, LAF, SYS). HAINAN: Chang-jiang Co., Reese et al. 17642A (IBSC, LAF, MO); Ling-shui Co., Reese et al. 17821 (IBSC, LAF, MO); Bau-long Forestry Station, Z.-H. Li & Yang 327 (IBSC, LAF, SYS); Jiu-gu-ling Mt., Tso 9l (IBSC, LAF). HONG KONG: Kow-loon Peninsula, Iwatsuki 47 (NICH); Da-Mo Mt. P.-J. Lin et al. 340 (IBSC); Da-Po-Kau, P.-J. Lin et al. 1081 (IBSC). TAIWAN: Botel Tobago, Schwabe 80 (NICH); To-na Co., Wang 0986 (NICH). YUNNAN: Jing-hong Co., Magill et al. 7837 (IBSC, LAF, MO).

Habitat: fairly common at low to moderate elevations on rocks, tree trunks and bases, rarely on soil; shaded habitats in forests along streams and rivers; 170–1250 m; Distribution: pantropical.

Calymperes afzelii is easy to recognize by its prominent teniolae, obscure upper laminal cells, and the peculiar extension of the costa in gemmiferous leaves as described above. It is often needlessly confused with C. erosum; see discussion under that species for distinctions. Calymperes tahitense is a close relative of C. afzelii, but the two do not seem to intergrade in China. See discussion under C. tahitense for distinctions.

Illustrations: Reese & P.-J. Lin 1991 (figs. 29–32).