Acidodontium Schwaegr., Sp. Musc. Frond., Suppl. 2(2): 152. 1827, nom. cons.
Bryum sect. Acidodontium (Schwaegr.) C. Müll., Syn. Musc. Frond. 1: 241. 1848.
Plants medium to robust, in dense or loose tufts, simple or forked. Leaves erect, erect‑spreading, or spreading when wet, oblong, oblong-lanceolate or lanceolate, often decurrent; apices acuminate; margins plane, or narrowly recurved below, entire to serrate or denticulate near apex; costa subpercurrent to excurrent; cells smooth, firm‑walled, often porose, upper cells rhomboid‑hexagonal, elongate rhomboidal or fusiform, basal cells quadrate to long‑rectangular. Setae elongate, straight. Capsules clavate-pyriform, erect to horizontal, symmetric, smooth, neck abruptly narrowed, long and slender; opercula hemispheric, sometimes apiculate; annuli large, compound, deciduous; stomata superficial; peristome double, exostome of 16 narrowly triangular teeth, abruptly narrowed above to slender filaments, papillose, yellowish red below, hyaline above; endostome yellow, papillose, basal membrane high, well‑developed, segments broad, split fully along the keel, each half strongly divergent, cilia rudimentary or absent. Spores spherical, papillose. Calyptra not seen.