Plants tiny to robust. Stem, except for initial stages, growing from a 2-sided apical cell. Leaves distichous, equitant, complex in form, consisting of two vaginant laminae that clasp the stem, a ventral lamina located above the vaginant laminae, and a dorsal lamina that occupies the length of the leaf opposite the vaginant and ventral laminae; costa single, usually well developed, near center of leaf, sometimes reduced, absent or nearly so. Seta elongate. Capsule cylindric, peristome single, teeth 16, haplolepidous, endostomate, usually divided 1/2-2/3 their length, sometimes irregularly divided or undivided, sometimes reduced, (rarely absent). Calyptra cucullate.