An order of the true mosses (subclass Bryidae) consisting of five families and 23 genera. The plants grow in mats or tufts in relatively exposed places, on trunks of trees and on rock. They are rather freely branched and prostrate, or may be sparsely forked and erect-ascending; the habit is more or less pleurocarpous, but sporophytes may be produced at the ends of leading shoots or branches. The leaves are generally oblong and broadly pointed, with a strong midrib. The upper cells are short and often papillose, while the basal cells are longer and often pellucid. The capsules are generally immersed and often ribbed, and the peristome, if present, has a poor development of endostome. The calyptrae are nearly always mitrate and often hairy. The Grimmiales, likewise somewhat pleurocarpous, differ in having single peristomes and a lesser development of neck tissue below the spore-bearing portion of the capsule.