Monographs Details: Symphyodon
Authority: Buck, William R. 1998. Pleurocarpous mosses of the West Indies. Mem. New York Bot. Gard. 82: 1-400.
Description:Genus Description - Plants slender to relatively robust, in lustrous, green to golden, mostly soft, thin to dense, flat mats. Stems creeping or occasionally pendent, irregularly branched, the branches ascending to prostrate, ± complanate-foliate; in cross-section with small thick-walled golden cells surrounding larger thinner-walled cells, central strand absent; rhizoids sparse, in pads, ± smooth; pseudoparaphyllia foliose; axillary hairs with 2 short brown basal cells and several elongate hyaline distal cells. Stem and branch leaves similar, crowded, semiflaccid to rigid, erect to wide-spreading, scarcely altered when dry, lanceolate to ovate, acute to short-acuminate, usually concave, shortly and slenderly decurrent; margins serrulate to serrate, mostly plane to narrowly recurved below; costa short and double, relatively strong, ending at or below midleaf; cells linear, often irregularly (i.e., not all cells) prorulose, firm-walled; alar cells in distinct but small groups, quadrate to rounded, cells of decurrencies mostly narrowly triangular. Asexual propagula none. Dioicous. Perichaetia inconspicuous; leaves differentiated, ± erect, mostly broadly oblong-lanceolate, broadly acuminate; margins serrulate to serrate above, ± entire below, plane; costa none; cells linear-flexuose, smooth to prorulose, thick-walled, becoming shorter and porose toward the insertion. Setae elongate, somewhat to strongly roughened above, smooth below, reddish; capsules erect, symmetric, cylindric, spinose, short-necked; exothecial cells subquadrate to short-rectangular, irregularly beset with hollow spines; annulus differentiated; operculum straight-rostrate; exostome teeth pale, narrowly triangular, somewhat shouldered, narrowly bordered, on the front surface smooth to finely papillose or obscurely cross-striolate at extreme base, not or scarcely trabeculate at back; endostome with a low to medium-high basal membrane, segments smooth or papillose, linear, keeled, narrowly perforate, shorter than the teeth, cilia none. Spores spherical, finely papillose, small to medium-sized. Calyptrae cucullate, naked, smooth.
Discussion:Symphyodon Mont., Ann. Sci. Nat. Bot. II, 16: 279. 1841; Stereodon sect. Symphyodon (Mont.) Mitt., J. Proc. Linn. Soc., Bot. Suppl. 1: 110. 1859.
Discussion. Symphyodon is primarily a genus of East Asian distribution with about a dozen species. When sterile it is mostly likely to be confused with Taxiphyllum because of the foliose pseudoparaphyllia, complanate leaves with linear prorulose cells, and scant alar development. However, careful examination will reveal the decurrencies, a feature never encountered in Taxiphyllum. Naturally, when sporophytes are available there is no other genus in the New World with which Symphyodon might be confused, and very few in the Old World (e.g., Chaetomitrium, Trachythecium). The genus was monographed by He (1992) as part of a dissertation.