Thallus with umbilicate areolae resembling apothecia, 0.5-1.5 mm broad, concave to flattish, or convex, round, brown, shining, often with pruinose margins; margins thick, pulverulent, lower side dark; over black hypothallus.

Apothecia to 1.6 mm, black, epruinose; margin thin, subpersistent; exciple black to exterior, paler inward; disk becoming rough and convex; hypothecium brown; epithecium brown; hymenium 100-140 µm, hyaline; paraphyses coherent, branched, septate, 2 µm, tips 3-4 µm; spores 8, 1-septate, with halo, becoming brown to black, 20-24 X 10-15 µm.

Reactions: medulla K—, C —, KC —, P —, I -; exciple K— or K+ violet; hypothecium K-, I—; epithecium K— or K+ violet; hymenium 1+ blue.

This species grows on silicate rocks in seepage areas, and in dry areas, sometimes covering large areas. It is circumpolar arctic, known from Novaya Zemlya, Scandinavia, Spitzbergen, Iceland, Greenland, Siberia, and North America.