Thuidium

Dioicous. Asexual propagules absent. Wefts on soil, rocks, logs or tree trunks. Stems regularly bipinnate or partly tripinnate, with rhizoids produced ventrally where in contact with substrate, typically at the base and apex; paraphyllia on stems crowded and mostly forked or shorter ones sometimes simple, those on branches more distantly spaced, more often simple, often confined to near base of branches, with ultimate branches often naked; central strand present, often weak. Stem and branch leaves strongly differentiated, mostly by size and shape; costa extending to 70 of leaf length to excurrent; laminal cells quadrate to oblong, uni- or pluripapillose abaxially, ornamentation weak or absent adaxially and often near apex; alar cells not differentiated. Stem leaves triangular or ovate, appressed to patent when moist, appressed, with incurved apices or patent when dry, cordate, plicate or not; apex acute, acuminate or rarely obtuse, sometimes piliferous or with a hairpoint; margin entire, crenulate, serrulate or denticulate, usually recurved at base, rarely plane throughout or incurved, without a border. Branch leaves broadly ovate to ovate-oblong, erect to wide-spreading when moist, appressed, erect or loosely imbricate when dry; apex acute or occasionally rounded or obtuse; margin crenulate, serrulate or denticulate, plane, without a border. Capsule mostly inclined to pendent, sometimes erect (not in Victoria), weakly to strongly curved, ellipsoid to cylindric, with an annulus. Calyptra cucullate or rarely mitrate (not in Victoria), smooth or rarely scabrous (not in Victoria), glabrous. Operculum conic to rostrate. Peristome double; endostome almost as tall as exostome, with a high basal membrane, sometimes more reduced (not in Victoria) and c. half exostome height with a basal membrane c. 1/3 of exostome height; cilia present or rarely absent (not in Victoria) or rudimentary (not in Victoria).