Bryum rubens Mitten, Hooker's J. Bot. Kew Gard. Misc. 8: 232. 1856

Plants small, red-green. Stems0.5-2 cm, fertile stems evenly foliate to weakly rosulate, innovations evenly foliate. Leaves of main rosette and innovations similar, innovation leaves smaller; somewhat irregularly twisted to contorted when dry, erect-spreading when moist, ovate, weakly concave, 1-2.5 mm; base not decurrent; margins recurved to mid leaf, distinctly serrulate distally, limbidium moderately distinct, of 1 or 2 rows of cells; apex acute; costa short-excurrent, awn pigmented; proximal laminal cells short-rectangular; medial and distal cells rhomboidal, 15-20 µm wide, 3-4:1, walls thin, not porose. Specialized asexual reproduction by rhizoidal tubers, , crimson, red to dark red, , (120-)150-300µm, . Sexual condition dioicous. Capsule nutant, red to red-brown, cylindric, 2-3 mm.

Capsules mature Apr-Aug. Disturbed soil, concrete; low to moderate elevations (0-1000 m); introduced; B.C., Que.; Calif., Md., N.J., N.Y., Okla., Tenn.; Europe; s Asia (India); Australia.

Rosulabryum rubens was probably introduced from Europe and is likely to be more widely distributed in temperate North America than records indicate. Although R. rubens was originally considered related to Gemmabryum subapiculatum, morphology as well as recent molecular work support a position near R. capillare.