Octoblepharum Moss

Octoblepharum albidum is a weedy and conspicuous moss that is distributed worldwide in the tropics. It grows especially on palms, often forming deep soft cushions. The flat, glossy, ligulate, spreading-recurved leaves distinguish it easily in the field from the superficially similar Leucobryum, which has erect or spreading, pointed, subtubulose leaves.

Plants small, 5–10 mm high, grayish green, somewhat glossy, in loose or dense tufts and cushions. Stems short, sparsely branched; central strand absent. Leaves erect-patent to curved spreading, 4–6 mm long, flattened, strap-shaped to ligulate from an oblong-ovate base, apiculate at the apex; hyaline lamina cells small, appearing only on two sides of costa at the leaf base; margins entire, with minute serration at the leaf apex; costa broad and thick, filling almost the entire upper lamina, convex on abaxial side in cross section, costal leucocysts 2–5 layers on adaxial side, 1–4 layers on abaxial side, supporting a nearly centrally positioned chlorocyst layer, chlorocysts in cross section triangular in the upper parts of leaves, quadrangular at the leaf base. Autoicous. Setae ca. 4 mm long, yellow, smooth; capsules erect, cylindrical; peristome teeth 8, yellowish, lanceolate with a broad base, vertically striate; opercula long rostrate, with an oblique beak. Calyptrae cucullate, smooth, entire at the base. Spores not seen.

Plants glossy, glaucous-green to white, often with pink tinge; densely cespitose; axillary hairs 3 per axil, 5-celled. Leaves spreading-recurved, fleshy, fragile when dry, 4-5 mm, apiculate, older leaves sometimes with rhizoids on tips. Specialized asexual reproduction rare, by gemmae. Seta yellow, 2-5 mm. Capsule brownish, 1-1.5 mm, ovoid-cylindric, slightly asymmetric, with stomata at base; operculum 0.8 mm; peristome of 8 blunt triangular pairs of teeth, teeth smooth or faintly striate, 200 µm tall, each composed of one interior and one exterior layer of intact, empty, cell-like plates; prostome present. Calyptra 1.5-1.9 mm. Spores finely papillose, 17-24 µm.

Distribution: China, India, Myanmar, Thailand, Vietnam, Malesia, Indonesia, the Philippines, Australia, Africa, and North, Central, and South America. The species is nearly pantropical, with its ranges extending to temperate regions in North America.

Habitat: on tree trunks.

Octoblepharum albidum (X.) Hedw. Descr. 3: 15. 1791
Bryum albidum L. Sp. PL e^. 2. fcffi S, 17jp. -J
Octoblepharum pallidum Besch.; Card. Mem. Soc. Sci. Nat. Cherbourg 32: 41; nomen nudum. 1900.
Octoblepharum mariinicense Mitt.; Card. Mem. Soc. Sci. Nat. Cherbotirg 32: 41; nomen nudum.