Monographs Details: Ectropothecium
Authority: Sharp, Aaron J., et al. 1994. The Moss Flora of Mexico. Part Two: Orthotrichales to Polytrichales. Mem. New York Bot. Gard. 69 (2)
Family:Hypnaceae
Scientific Name:Ectropothecium
Description:Species Description - Plants small to medium-sized, in ± shiny, yellow-green to brownish-yellow mats. Stems creeping, regularly to irregularly pinnate-branched, in section showing a weakly developed central strand; pseudoparaphyllia filamentous or linear-lanceolate Stem and branch leaves only slightly differentiated, falcate-secund, ± concave, ± plicate, ovate- to oblong-lanceolate, short or long-acuminate; margins plane, sermlate above; costa short and double, sometimes indistinct; cells linear, smooth or papillose because of projecting upper ends; alar cells only slightly differentiated, with one considerably enlarged, hyaline cell at the extreme angles and a few quadrate or subquadrate supra-alar cells. Autoicous or dioicous. Setae smooth; capsules horizontal to pendent, small, ovoid, deeply constricted below the mouth when dry; annulus present; exostome teeth lance-subulate, pale-yellow and cross-striolate below, pale and finely papillose above, low-trabeculate at back; endostome about as long as the exostome teeth, consisting of a high basal membrane and keeled segments alternating with ciha. Spores minutely papillose. Calyptrae naked.

Discussion:The genus is similar to Hypnum in appearance, but distinctive features include the small, ovoid capsules not much longer than broad and deeply constricted below the mouth w h e n dry and alar cells with a single, strongly enlarged cell at the extreme angles.