Stems to ca. 2 cm, occasionally longer. Sexual condition paroicous or synoicous. Seta to 2 cm, straight to somewhat flexuose, smooth, red or reddish-brown, occasionally yellowish brown. Capsule brown, 1--1.5 mm, inclined, ovoid to oblong-ovoid, becoming ± wrinkled when dry; operculum to 0.3 mm; peristome teeth 16, united below by a pale yellow or hyaline membrane, the teeth in 8 groups of 2, irregularly split and perforated, smooth or very finely papillose. Spores finely papillose to roughened, 30--45 µm.

Capsules mature late summer--fall. In the Arctic the species is found on calcareous soil, often in frost cushions; Greenland; N.W.T., Nunavut; Ala.; n and arctic Europe; e Asia (China, Mongolia), arctic Asia (Siberia).

This is a primarily high Arctic or high elevation species, morphologically close to D. inclinatum and is sometimes considered as synonymous with that species. The primary difference is in the peristome. The 16 peristome teeth of D. hagenii are grouped in 8 pairs united by a pale yellowish basal membrane, each tooth irregularly split and perforate. A report of the species from Newfoundland is referable to D. inclinatum (redetermined by Guy Brassard according to Crum and Anderson 1981). In the southern part of the species European range it grows on sandy or loam soil close to the sea.