Monographs Details: Calyptothecium
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:Pterobryaceae
Scientific Name:Calyptothecium
Description:Genus Description - Plants rather robust, in loose, soft, green, yellow-green or golden, shiny mats. Secondary stems spreading to pendent, loosely and irregularly 1-pinnate from a ± stipitate base; branches well spaced, unequal, generally somewhat flattened, blunt or rarely flagellate-tapered. Cylindric, septate g e m m a e frequent in leaf axils. Leaves spreading and usually ± complanate and undulate, broadly oblong-ovate or elliptic, short-acuminate, cordate-auriculate at base; margins incurved on 1 or both sides at the base, entire or serrulate at the apex; costa single, slender, ending above the midleaf (or rarely lacking); cells smooth, linear, 50-75 x 7.5-10 µm, thin-walled but ± pitted, those at the apex narrowly rhomboidal, those at the base shorter, laxer, brown, not differentiated at the basal angles. Perichaetial leaves lance-acuminate from a broader, sheathing base. Capsules immersed, ovoid; peristome double; exostome teeth reddish, smooth or nearly so, with preperistome fragments; endostome consisting of a low membrane and narrow segments as long as the teeth. Calyptrae mitrate, naked.

Discussion:

The plants are loosely once-pinnate from an inconspicuously stipitate base. The leaves are generally somewhat complanate except at the tips ofthe branches, and they are nearly always undulate, though rarely very strongly so. The rounded-auriculate leaf bases, with scarcely differentiated alar cells, are distinctive.