Plants small to large, green or yellowish green. Stems pinnate ± in one plane or irregularly branched to almost unbranched; hyalodermis present, central strand present; paraphyllia absent; rhizoids or rhizoid initials on stem or abaxial costa insertion, rarely forming tomentum, slightly branched, smooth; axillary hair distal cells 1-8, hyaline. Stem leaves crowded, circinate, falcate, or almost straight, lanceolate, plicate or rarely not, 0.3-1.7 mm wide; base not or hardly decurrent; margins sometimes incurved proximally, plane or recurved distally, finely denticulate or entire proximally, very finely to strongly denticulate distally, limbidia absent; apex acuminate to very long-acuminate; costa single, ending in acumen; alar cells differentiated, short- to long-rectangular, inflated, hyaline, region transversely triangular or ± isodiametric; medial laminal cells linear; marginal cells 1-stratose. Sexual condition autoicous. Capsule horizontal, erect, or inclined, cylindric or short-cylindric, curved to straight; peristome perfect or specialized; exostome teeth with margins dentate distally; endostome cilia well developed, rudimentary, or absent. Spores 10-21 µm.