Leaves commonly distant and exposing the stem; short-lanceolate to ligulate, (0.4--)1--1.5(--1.8) mm; apex narrowly to broadly acute, apiculus short-triangular; margins 1-stratose; costa percurrent in distal leaves, ending in a clear, sharp cell. . Specialized asexual reproduction absent. Sexual condition dioicous. Capsule 0.5--1 mm, exceeding the theca in length, ovoid, inclined.

Forming deep-green cushions on calcareous and non-calcareous rock, sandstone walls, rock ledges, exposed moist crevices, wet areas; 10--3300 m; Greenland; B.C.; Alaska, Ariz., Colo., Wash.; Mexico; West Indies; Central America; South America; Eurasia; Africa; Atlantic Islands; Australia; Pacific Islands (Hawaii, New Zealand).

Plants of Anoectangium aestivum often exhibit a comal tuft, and have leaves with multifid or occasionally 2-fid papillae, these dense and obscuring the cell lumens. Specimens from Massachusetts identified as this species are Hymenostylium recurvirostrum. Sporophytes are rare in the range of the flora.