Monographs Details: Brachythecium
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:Brachytheciaceae
Scientific Name:Brachythecium
Description:Genus Description - Plants small and slender to moderately robust, yellow- to dark-green, in loose or dense, intertwining mats. Stems prostrate or rarely erect-ascending, irregularly to ± regularly pinnate, often tapered or stoloniform; branches straight or flexuose, ± tapered, sometimes hooked at ends. Leaves straight or occasionally secund, imbricate to wide-spreading when dry, generally more spreading when moist. Stem leaves generally concave, smooth to strongly biphcate, lanceolate to broadly ovate-cordate (generally ovate-lanceolate), gradually to abmptly narrowed to a short or long, straight or flexuose acumen (occasionally bent to 1 side), slightly to strongly decurrent; margins plane or recurved at base and sometimes beyond, occasionally well into the acumen, entire to serrate; costa very slender or stout, extending to the leaf middle or into the acumen, occasionally forked, sometimes ending as an inconspicuous dorsal spine; upper cells smooth, fusiform to linear, generally becoming lax toward the base; basal cells quadrate to linear, with ± pitted walls; alar cells little to distinctly differentiated as few to many, quadrate to rectangular, small to inflated cells. Dioicous or monoicous. Setae smooth or papillose; capsules erect to horizontal, oblong-ovoid to cylindric, generally curved; annulus ± differentiated; operculum conic to conic-rostrate (generally apiculate); exostome teeth lance-subulate, brown or red-brown, cross-striolate below, papillose at the tips, trabeculate; endostome ± papillose, the segments keeled, from a high basal membrane, the cilia well developed or rarely mdimentary or lacking. Spores smooth or papiUose.

Discussion:

Brachythecium rutabulum (Hedw.) B.S.G. is included in the key as it has been found in the western United States, Guatemala, and South America.) It has a rough seta, autoicous sexuality, and somewhat decurrent leaves.