Plants: very small, gregarious or loosely caespitose. Stems: to 1 mm, erect, rarely branching, Leaves somewhat crisped when dry, erect-spreading when moist, ovate to oblong, concave, 1.5–2.5 mm; margins entire; apices acuminate; costa single, percurrent, filling most of acumen; proximal laminal cells rectangular, distal cells short-rectangular to hexagonal. : Specialized asexual reproduction by occasionally stalked, spherical, dark purple rhizoidal tubers. Sexual: condition autoicous. Seta: erect, to 1.5 mm. Capsule: stegocarpous, erect, mostly exserted, globose and mostly urceolate following dehiscence, sharply constricted to neck, to 1 mm, wrinkled when dry, neck short, abruptly narrowed to seta; exothecial cells thin-walled, irregular in shape except for narrowly rectangular suboral cells; stomata with single guard cell, restricted to neck, superficial to rarely somewhat immersed; annulus none; operculum plane; peristome absent. Calyptra: long-persistent, large, enclosing entire capsule and seta, four-angled, beaked, opening by longitudinal slits for nearly entire length to the clasping base. Spores: spherical to angular, smooth. c United States, Europe, Africa.