8. Calymperes serratum A. Braun ex C. Müll., Syn. Musc. Frond. 1:527. 1849.
Plants dark green, unbranched, in low dense tangles, with stemless appearance. Stems very short; rhizoids glossy blackish red. Leaves monomorphic, curled when dry and with bases conspicuously pale, straight when wet, linear above slightly broader base, to l3 mm long but mostly shorter, with abundant pale axillary hairs with longest median cells mostly less than twice as long as wide; costa percurrent or short-excurrent, smooth; cells of upper laminae unistratose, mostly or partly transversely elongate, smooth abaxially and adaxially; margins thickened, toothed in two rows; teniolae lacking; distal cells of cancellinae gradually blending with adjacent green cells of upper laminae. Gemmae infrequent, adaxial on leaf tip, roughened, irregularly branched. Sporophytes not seen.
Type. Indonesia: Java, Junghun s.n. (isotype H).
Chinese specimens examined: HAINAN: Chang-jiang Co., P.-J. Lin & Z.-H. Li 456 (IBSC, LAF, MO, SYS); Le-dong Co., P.-J. Lin & Z.-H. Li 522 (IBSC, LAF, SYS), Reese 17730 (LAF, MO); Ling-shui Co., Redfearn et al. 36224 (IBSC, LAF, MO).
Habitat: on tree trunks and bases, decaying logs, and rocks in humid forests at 740–1000 m; Distribution: China, Japan, Malaysia, Australia, Oceania, and western tropical Africa.
Plants of C. serratum closely resemble those of C. lonchophyllum and C. levyanum var. hainanense, but differ consistently in the distal cells of the cancellinae, which gradually merge with the green cells of the upper laminae instead of being sharply separate, and in the much shorter cells of the axillary hairs.
Illustrations: Reese & P.-J. Lin 1991 (figs. 10–15).