Monographs Details: Erythrodontium
Authority: Buck, William R. 1998. Pleurocarpous mosses of the West Indies. Mem. New York Bot. Gard. 82: 1-400.
Description:Genus Description - Plants medium-sized, in lustrous, green to golden to red-brown, mostly stiff, lax mats. Stems creeping, irregularly pinnately branched, with branches relatively short and julaceous; in cross-section with small thick-walled often colored cells surrounding larger thinner-walled cells, central strand present, small; pseudoparaphyllia foliose; axillary hairs with a single short brown basal cell and (l-)3 elongate hyaline smooth distal cells. Stem and branch leaves slightly differentiated, crowded, stem leaves larger, usually broadly ovate, gradually acuminate, branch leaves julaceous when dry, somewhat spreading when moist, short- to long-oblong-ovate, abruptly apiculate, slightly concave to cucullate, not plicate, broadly decurrent; margins usually serrulate above, entire below or rarely throughout, plane or rarely recurved; costa short and double, occasionally absent; cells linear-rhomboidal, smooth, ± thin-walled, becoming shorter and thick-walled in the extreme apex; alar cells differentiated in large areas in the basal angles, oblate, extending 1/4-1/2 the leaf length up the margins, usually not reaching the costa, those in the decurrencies similar to others. Asexual propagula none. Autoicous. Perichaetia large, along stems; leaves convolute, elongate, oblong-lanceolate, ± abruptly acuminate; margins entire to serrulate above, entire below, plane; costa none; cells linear, straight, smooth, thin-walled, becoming shorter, thicker-walled and flexuose at the apex, becoming larger, lax, and rectangular toward the insertion; alar cells not differentiated. Setae elongate but relatively short and stout in most species, only occasionally >1 cm long, smooth, red or yellow, slightly twisted; capsules erect, symmetric, short-cylindric, yellow-brown to dark red-brown; exothecial cells quadrate to short-rectangular, thin- to thick-walled, not collenchymatous; annulus not differentiated; operculum conic, short- to long-rostrate, straight; columella narrowly cylindric, sometimes exserted; exostome teeth narrowly triangular, yellow-brown to reddish, not shouldered, very narrowly bordered, on the front surface with a ± straight median line and relatively broad plates, smooth, striate or papillose below, ± smooth above, without prostome, not trabeculate at back, sometimes perforate, smooth; endostome rudimentary, with no basal membrane, segments smooth, linear, flat, not perforate, as long as the teeth, or more commonly discontinuous and adhering to the teeth, cilia none. Spores spherical, finely to coarsely papillose. Calyptrae cucullate, naked or sparsely hairy, smooth.
Discussion:Erythrodontium Hampe, Vidensk. Meddel. Dansk Naturhist. Foren. Kj0benhavn III, 2: 279. 1870.
Entodon sect. Leptohymenium Mitt., J. Linn. Soc., Bot. 12; 522, 523. 1869.
Discussion. Erythrodontium is characterized by its julaceous branches, and relatively broad leaves with numerous oblate alar cells. The capsules are erect with a rudimentary endostome. It is separated from Mesonodon by its stouter setae, lack of prostome development, and nonplicate leaves. From Entodon, Erythrodontium is distinguished by its broader leaves with more numerous oblate alar cells (rather than fewer subquadrate alar cells). The decurrent leaves are also useful in recognition.
The genus is often characteristic of somewhat dry habitats. It occurs in Asia (one species) and South America but is particularly speciose in Africa. We have only a single species in the West Indies.