Plants: to 2.5 mm. Leaves: ligulate to lingulate, 1–2.8 mm, margins entire, undifferentiated at base, apex cucullate to nearly open; costa subpercurrent to percurrent, filaments of 3–6 cells, cells subspheric; cells of leaf base 15–64 µm, medial and distal cells 11–24 µm, occasionally with large solid papillae at leaf tip. Sexual: condition dioicous or rhizoautoicous. Seta: 5.5–12.5 mm. Capsule: urn cylindric, 1.5–3 mm; operculum campanulate, 1–1.4 mm; peristome 600–1200 µm, strongly twisted. Spores: 13–24 µm. Phenology: Capsules mature Jan–May.
Low, desert areas, banks and dry washes, soil and limestone. moderate elevations (400-800 m). Ariz., Calif., Mexico (Baja California), Europe, Asia (India, Israel, Jordan, Lebanon, Turkey), n Africa, Australia.
In var. ambigua, the cylindric capsules with a long and twisted peristome are distinctive. Forms with short-lingulate leaves may be confused with Aloina hamulus when sterile. Outside North America, var. ambigua may occur as high as 2100 m.