Bryum Hedw. Sp. Musc. Frond. 178. 1801.
Rosulabryum Spence, Bryologist 99: 222. 1996, syn. nov.
Plants small to robust, in erect, dense or loose tufts, simple or forked. Leaves erect to erect‑spreading when dry, spreading when wet, ovate, ovate‑lanceolate, lanceolate, oblong-lanceolate, oval, elliptic, or suborbicular, often decurrent; apices obtuse, acute or acuminate, concave; margins plane, erect, or recurved, entire to serrate near apex; costa strong, subpercurrent to excurrent; cells smooth, thin‑ or thick‑walled, quadrate to long‑rectangular below, rhomboid‑hexagonal to elongate rhomboid above. Setae elongate, straight or flexuose. Capsules subcylindrical, clavate, pyriform, subglobose or ovoid, erect or nodding to pendent, symmetric or curved, smooth, neck well-developed; opercula conic‑apiculate; annuli large, compound, deciduous; stomata superficial; peristome diplolepidous, exostome teeth 16, narrowly triangular, papillose, yellow to brown; endostome yellowish hyaline, lightly papillose, basal membrane well‑developed, segments keeled, narrowly or broadly perforate, cilia 2‑3, nodose or appendiculate, rudimentary or absent. Spores spherical, smooth or papillose. Calyptrae cucullate, smooth, naked.