Leucophanaceae M. Fleischer
William D. Reese
Plants glossy or dull, white, whitish- to glaucous-green, purplish, or brownish, often with pink or red tinge below. Stems simple or forked; rhizoids brown, inconspicuous; axillary hairs slender, proximal cell elongate, with brownish walls. Leaves erect to spreading-recurved, ligulate to lanceolate from clasping base, multistratose above, border of elongate hyaline cells present or lacking, with 1-stratose wings of lamina in base, largely composed of internally and externally porose hyaline empty cells, chlorophyllose cells in 1--3 internal layers, forming a network immersed among the hyaline cells; typical costa present or lacking. Specialized asexual reproduction by 1-seriate gemmae borne at leaf tips. Sexual condition autoicous; perigonia numerous, minute, gemmiform, axillary, stalked, with a few highly reduced leaves. Perichaetia terminal, inconspicuous, leaves small, otherwise scarcely differentiated. Seta single, straight, smooth. Capsule erect, exserted; operculum obliquely rostrate; peristome single, of 8--16 linear to triangular, sometimes apparently multicellular teeth, the teeth single or all or partly paired, smooth or variously decorated, each tooth composed of an interior and an exterior layer of sometimes cell-like plates with thin or variously thickened walls, portions of the walls of the plates sometimes eroded away, prostome present or lacking. Calyptra cucullate, smooth. Spores granular-papillose.
Genera 4(5), species ca. 34 (1 species in the flora): worldwide in the tropics and subtropics.
The multistratose "leucobryaceous" leaves of Octoblepharum, the sole representative of the family in the flora, may be taken to indicate relationship with other mosses having similar leaves. But the distinctive peristome of Octoblepharum makes the genus difficult to classify in the Leucobryaceae, where it has traditionally been assigned, or in the Calymperaceae, where it has also been placed and from which it differs markedly in leaf structure. A. Eddy (1990) assigned the genus to its own monogeneric family, Octoblepharaceae (illegitimate name), based on its peristome, but Octoblepharum seems best classified in the Leucophanaceae, where it was placed by M. Fleischer (1904), along with three genera of similar mosses.
Eddy, A. 1990. A handbook of Malesian mosses, Vol. 2. Leucobryaceae to Buxbaumiaceae. London. Fleischer, M. 1904. Die Musci der Flora von Buitenzorg, Vol. 1. Leiden. Robinson, H. 1985. The structure and significance of the leucobryaceous leaf. Monogr. Syst. Bot. Missouri Bot. Gard. 11: 111--120. Robinson, H. 1990. A functional evolution of the Leucobryaceae. Tropical Bryology 2: 223--237.