Plants 0.5–2 mm. Leaves lingulate to suborbicular, 0.5–1.5 mm, margins entire, undulate-denticulate distally, differentiated at base, apex cucullate to nearly open; costa subpercurrent, filaments of 2–5 cells, cells subspheric to cylindric; cells of leaf base 13–66 µm, medial and distal cells 13–40 µm, papillae none. Sexual condition synoicous or dioicous. Seta 6–17 mm. Capsule urn cylindric, 1–2 mm; operculum conic, short-rostrate, erect or inclined, 0.5–1 mm; peristome 250–900 µm, twisted. Spores 15–25 µm.
Phenology: Capsules mature (Mar-)May–Aug.
Habitat: Bare or disturbed soil or silt, roadside banks, calcareous boulders or gravel
Elevation: low to moderate elevations (100-1500 m)
Greenland, Alta., B.C., Man., N.W.T., Nunavut, Ont., Yukon, Alaska, Mont., Europe, Asia (Siberia).
The leaves of Aloina brevirostris are usually short, and cucullate with a reduced lamina; forms with larger laminae may be confused with A. rigida, but the synoicous condition and the cylindric capsules with a conical operculum are diagnostic. The latter species is dioicous, and has ovoid-cylindrical capsules with a long-rostrate operculum.