Monographs Details: Polytrichum
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 - Medium-sized to robust plants, in loose tufts. Leaves with differentiated sheath and limb, usually squarrose-reflexed at the hinge between sheath and limb, erect to erect-spreading when dry, often broadly spreading when wet, broad-nerved, lamellate on the upper surface of both nerve and lamina, the sheath hyaline-margined; limb sharply serrate or with broadly inflexed, entire margins; marginal cells of lamellae distinctly differentiated from other lamellar cells. Dioicous or rarely monoicous. Perigonial bracts forming a conspicuous rosette. Setae solitary; capsules sharply angled; apophysis sharply delimited by a deep constriction, with stomata confined to the groove; exothecium glaucous in fresh capsules, the exothecial cells mammillose, with sharply defined pits; peristome teeth 64, with vertical keels at back; epiphragm remaining attached to the peristome teeth, thin and delicate except at the edge, its lower margin dissected into lobes alternating with the teeth. Calyptra producing from its tip a dense, matted felt of hairs commonly enclosing the whole capsule.