Plants elliptic to globose, occasionally three-angled, 1-1.5 mm. Stem leaves awned, broadly channeled; laminal cells papillose abaxially. Seta as long as the diameter of the capsule. Spores spheric, 35-40 µm, papillose. Capsules mature winter. Soil, dry washes; low to moderate elevations; Ariz., Ill., Iowa, Kans., Tex.; Mexico (Nuevo León). Acaulon schimperianum is awned and the distal margins are more strongly dentate than those of the other species.