Monographs Details: Entodon
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 to moderately robust, in lustrous, green to yellow-green or golden-brown, mostly soft, thin to dense, flat, often extensive mats. Stems creeping or occasionally ascending, irregularly to subpinnately branched, with branches relatively short, terete-or complanate-foliate; in cross-section with small thick-walled often colored cells surrounding larger thinner-walled cells, central strand present or absent; pseudoparaphyllia foliose; axillary hairs with a single short brown basal cell and 3 elongate hyaline smooth distal cells. Stem and branch leaves similar, crowded, oblong-lanceolate to oblong-ovate, obtuse to acuminate, usually acute, concave, not plicate, not decurrent; margins usually serrulate above, entire below or rarely throughout, plane, erect or reflexed below; costa double, very short to ending near midleaf; cells linear, straight to ± flexuose, smooth, thin- to firm-walled, rarely thick-walled, often becoming shorter in the extreme apex, becoming shorter and mostly porose toward the insertion; alar cells numerous, quadrate to subquadrate, reaching the costa or not. Asexual propagula none. Autoicous or rarely dioicous. Perichaetia large, along stems and branches; leaves sheathing, erect or reflexed, lanceolate to oblong-lanceolate, acute to acuminate; margins serrulate above, entire below, plane; costa none or short and double; cells linear, smooth, becoming rectangular toward the insertion; alar cells not differentiated. Setae elongate, smooth, red or yellow; capsules erect, symmetric, cylindric, yellow- to red-brown; exothecial cells short-rectangular, thin- to thick-walled, not collenchymatous; annulus differentiated or not; operculum high-conic to obliquely rostrate; columella long and narrowly cylindric, often exserted; exostome teeth narrowly triangular, yellow-brown to reddish, not shouldered, narrowly bordered, on the front surface with a ± straight median line and relatively broad plates, variously striolate or papillose, rarely smooth, without prostome, not or slightly trabeculate at back, often perforate, papillose, striolate or smooth; endostome with a low basal membrane, segments striate, papillose, or smooth, linear, keeled, mostly perforate, as long as or shorter than the teeth, rarely rudimentary, cilia none. Spores spherical, papillose. Calyptrae cucullate, mostly naked, smooth.
Discussion:Entodon Müll. Hal., Linnaea 18: 704. 1845.
Cylindrothecium Bruch & Schimp. in Bruch, Schimp. & W. Gümbel, Bryol. Eur. 5(fasc. 46-47, Monogr. 1): 111. 1851, nom. illeg.; Stereodon sect. Cylindrothecium (Bruch & Schimp.) Mitt., J. Linn. Soc., Bot. 4: 88. 1859, comb. illeg.; Entodon sect. Cylindrothecium Mitt., J. Linn. Soc., Bot. 12: 522, 525. 1869.
Discussion. Entodon is characterized by ovate-lanceolate leaves, often more or less oblong, with short, double costae, linear upper cells, and quadrate alar cells in sizable groups. The capsules are erect and the double peristome is inserted below the mouth of the urn. There are two subgenera, both in our flora, subgen. Entodon and subgen. Erythropus (Broth.) Mizushima. Subgenus Entodon is distinguished by ± complanate, yellow- to bright-green plants, often with weakly costate leaves. The seta is often yellow, the annulus is not differentiated, and the exostome teeth are usually red-brown and striolate. In subgen. Erythropus the plants are usually more or less terete and dark-green with relatively well-developed costae. The seta is mostly red, the annulus is composed of 2-5 rows of thick-walled, deciduous cells, and the exostome teeth are mostly yellow- to dark-brown and usually papillose.
The nonplicate leaves will distinguish Entodon from Mesonodon and the nondecurrent leaves and alar cells subquadrate rather than oblate will separate the genus from Erythrodontium.
Entodon has well over 100 species, many of which are best recognized on the basis of peristomial ornamentation. The genus is best represented in Andean South America and eastern Asia. Although the South American species have not been monographed, Entodon has been revised for Japan (Mizushima, 1960) and China (Hu, 1983). In the West Indies the genus is not particularly troublesome or diverse.