Monographs Details: Distichium
Authority: Sharp, Aaron J., et al. 1994. The Moss Flora of Mexico. Part One: Sphagnales to Bryales. Mem. New York Bot. Gard. 69 (1)
Description:Genus Description - Slender but often elongate plants in dense, tomentose tufts. Leaves distichous, with an erect, oblong, sheathing base abruptly narrowed to a rough, spreading, linear subula; costa very rough, excurrent, filling most of the subula; upper cells small, subquadrate or short-rectangular, green and obscure, roughened because of thickened cross-walls; lower cells linear or oblong-linear, smooth and pellucid. Autoicous. Perichaetial leaves not notably differentiated. Setae erect, elongate; capsules cylindric or ovoid-cylindric, erect and symmetric or strongly inclined and ± asymmetric, finely wrinkled when dry; annulus large, compound, deciduous in fragments or ± persistent; operculum low-conic; peristome inserted somewhat below the mouth, dark-brown or red-brown, consisting of 16 lanceolate teeth variously split or perforated or 8 groups of about 4 irregular, filiform segments. Spores spherical. Calyptrae cucullate, smooth.
The distichous leaves consisting of a sheathing base and a slender roughened subula may give evidence of a relationship outside the Ditrichaceae, and the curious grouping of peristome segments may be phylogenetically significant.