Plants small, pale-greenish, in low turfs and clumps. Stems short, forked; rhizoids reddish brown. Leaves dimorphic, curled-contorted when dry, straight when wet, vegetative leaves oblong-lanceolate, gemmiferous leaves acuminate distally with often spatulate tips, 2.5–4.0 mm long, axillary hairs inconspicuous; costa percurrent, often long-extended beyond broad laminae and with narrow wings of laminae in gemmiferous leaves; cells of upper laminae isodiametric, obscure, smooth to unipapillose abaxially, mammillose-papillose adaxially; margins mostly thickened, sometimes unistratose, entire except sometimes irregularly serrate at shoulders; teniolae lacking; cancellinae usually broadly to narrowly acute distally. Gemmae common, borne on adaxial surface of costa, often in distinct saucer-shaped gemma receptacles on tips of modified leaves. Sporophytes not seen.

Type. Samoa, insula Upolu, Graeffe s.n. (isotypes BM, FH, NY).

Chinese specimens examined: HAINAN: Bau-long Forestry Station, P.-J. Lin et al. 311 (IBSC, LAF, SYS); Chang-jiang Co., P.-J. Lin et al. 3051 (IBSC, IFP, LAF); Ling-shui Co., P.-J. Lin et al. 2593 (IBSC, LAF, PE). YUNNAN: Meng-la Co., Redfearn et al. 33829 (IBSC, LAF, MO).

Habitat: infrequent and rarely abundant; on tree trunks and rock in forests at low elevations, 160–200 m; Distribution: very widespread in the palaeotropics, from tropical eastern Africa eastward throughout Malaysia, Australia, and Oceania.

Calymperes graeffeanum is a variable species but easy to recognize by its lack of teniolae and production of gemmae only on the adaxial surface of the leaf tips, often in a gemma receptacle. This species has been reported from China under the name Calymperes dozyanum Mitt. Ellis (1988) provided an explanation of the confusion surrounding this name. Calymperes moluccense is grossly similar to C. graeffeanum but has distinct teniolae. Calymperes tenerum is also similar, in that it lacks teniolae, but it bears gemmae all around the tips of the excurrent costae. In the absence of gemmae, it may not be possible to distinguish C. graeffeanum from C. tenerum with certainty, although the distally truncate cancellinae of C. tenerum are different from the distally acute cancellinae of C. graeffeanum.

Illustrations: C. Gao (ed.) 1996 (Pl. 32, figs. 5–9).