2. Plagiopus Bridel, Bryol. Univ. 1: 596, plate 5, fig. 5. 1826. • [Greek plagios, oblique, and pous, foot, alluding to curved seta].
Plants in dense tufts, dull olive green to brownish. Stems 2-10 cm, erect to ascending, 2-fid; triangular in cross section, hyalodermis present, epidermis not prorulose; radiculose proximally, rhizoids papillose. Leaves in 3 rows, laxly erect or erect-spreading and somewhat curved when dry, erect-spreading when moist, narrowly lanceolate, 1-stratose, often 2-stratose at distal margins; base not sheathing; margins revolute nearly throughout, often serrate distally, teeth paired; apex acuminate; costa percurrent to short-excurrent, abaxial surface serrulate; basal laminal cells longer than distal cells; distal cells subquadrate or short-rectangular, faintly striate, walls thick. Specialized asexual reproduction unknown. Sexual condition synoicous; perigonia absent; perichaetial leaves scarcely distinct. Seta single, elongate, straight or flexuose. Capsule suberect, subglobose, furrowed when dry, mouth small; annulus absent; operculum short-conic or convex; peristome double; exostome teeth reddish brown, lanceolate, smooth or minutely papillose, apically free; endostome yellowish to hyaline, segments broad, cilia short, rudimentary, or absent. Spores ellipsoid, coarsely papillose.
Species 1: nearly worldwide, except Antarctica.
Plagiopus is distinguished by its triangular stems, striated laminal cells, and leaves appearing papillose in cross section.