Plants: often blackish or dark brown, sometimes olive green. Leaves: secund to often deciduous, lanceolate-subulate, obtuse, costae filling subula; margins denticulate at apex, entire below, leaf cells (1–)3:1, quadrate to rectangular-elliptic; perichaetial leaves abruptly subulate. Seta: 3–13 mm, flexuose. Capsule: ovate to narrowly pyriform, peristome of 16, lanceolate teeth; columella not developed. Spores: 13–20 µm.
Moist or dripping acidic rock faces, most common in montane/alpine habitats. low to high elevations (0-3000 m). Greenland, Alta., B.C., N.B., Nfld. and Labr. (Nfld.), N.W.T., N.S., Nunavut, Ont., Que., Yukon, Alaska, Calif., Colo., Mich., Minn., Mont., N.H., N.Y., N.C., Oreg., Pa., Tenn., Vt., Wash., Wyo., Central America (Guatemala), Europe, Asia, Africa, Atlantic Islands (Iceland).
Blindia acuta forms soft blackish mats on acidic rocks in moist arctic, alpine, and montane habitats. The well-developed alar cells, smooth leaf cells, subulate leaves, and short-ovate, smooth capsules with well-developed, smooth peristome teeth are distinguishing features. Seligeria species are smaller and occur on calcareous rocks.