Plants small, medium-sized, or robust, flattened, sometimes with an intense blackish color. Pri-mary stems creeping, sympodially branched, often stoloniferous, occasionally pendent; rhizoids from circular clusters of initials abaxial to the stolon leaf insertions and at the base of secondary stems; leaves reduced, widely spaced, appressed to spreading. Stems horizontal or erect, not stipitate or stipitate-frondose, sometimes pendent, irregularly branched, complanate-foliate, at times flagellate-attenuate; cross section of secondary stems with sclerodermis, enlarged cortical cells, central strand present or absent; paraphyllia present or absent; pseudoparaphyllia present or absent. Stipe leaves erect, erect-spreading, or squarrose. Secondary stem and branch leaves symmetric or asymmetric, smooth or undulate, decurrent or rarely not decurrent; margins often inflexed on one side below, sometimes coarsely dentate at apex, occasionally with intramarginal limbidia; costae double or single, long or short, often forked or branched near tip, sometimes ending in a small spine on the dorsal surface; cells smooth or prorate; alar cells weakly differentiated. Asexual reproduction some-times by deciduous leaves or filiform, microphyllous branchlets. Dioicous, synoicous, or autoicous. Perichaetia at times ramentose. Setae elongate or short, smooth throughout or smooth below and mammillose above. Capsules immersed or exserted, erect to suberect, symmetric or asymmetric; stomata present or absent; opercula rostrate; peristome diplolepideous; exostome teeth, linear or nar-rowly triangular, dorsal surface cross-striate below or papillose; endostome basal membranes low or high, segments perforate, keeled or not keeled, cilia well developed (nodose or appendiculate), rudi-mentary or absent. Calyptrae cucullate or mitrate and lobed, naked, sparsely hairy, densely ramen-tose, or smooth.