Monographs Details: Homomallium
Authority: Sharp, Aaron J., et al. 1994. The Moss Flora of Mexico. Part Two: Orthotrichales to Polytrichales. Mem. New York Bot. Gard. 69 (2)
Description:Genus Description - Plants small or medium-sized, in yellow- to dark-green, ± shiny mats. Stems creeping, radiculose, in section dorsiventrally flattened and elliptic, with a slightly developed central strand, regularly to irregularly pinnate, with branches short, erect-ascending, ± curved. Stem and branch leaves not or slightly differentiated (the stem leaves somewhat broader), erect-spreading or homomallous, concave, ovate- to oblong-lanceolate, short- to long-acuminate, not or slightly plicate; margins plane or recurved below, subentire or somewhat sermlate above; costa double, short to long (rarely single or forked above); cells broadly and shortly oblong-rhomboidal to linear-rhomboidal, smooth or minutely papillose at upper angles, those in the alar regions subquadrate in several rows. Autoicous. Perichaetial leaves erect, oblong-lanceolate, short- to long-acuminate, entire to serrulate above, nearly smooth. Setae smooth; capsules ± inclined to horizontal, oblong-cyhndric and curved, constricted below the mouth when dry and empty; exothecial cells rounded-hexagonal to rectangular, with walls moderately to distinctly thick-walled; annulus present; operculum conic-apiculate to rostellate; exostome teeth lance-subulate, pale-yellow, cross-striolate below, pale and finely papillose above, trabeculate; endostome free, about as long as the exostome, consisting of a high basal membrane, keeled, split, nearly smooth to papillose segments, and cilia 1-3 and nodulose. Spores nearly smooth to minutely papillose. Calyptrae naked.
Discussion:Diagnostic features include subquadrate alar cells in a distinct group and (generally) inclined to horizontal, curved-cylindric capsules constricted below the mouth when dry, with the peristome perfect and cilia well developed.