crustose, olive-green to whitish green, partly slightly pruinose, continuous to areolate to strongly verrucose-warty, lacking soredia or isidia; hypothallus indistinct. Apothecia
immersed in areolae, appearing like Pertusaria; disk
black, concave deeply, at first ostiolate, becoming broader, with a thin darkening border around ostiole within thalloid margin; hypothecium
pale yellowish or brownish; epithecium
K—, HC1—, HN03—; hymenium
hyaline, inspersed at times, 1+ blue; paraphysoids slender, 1.5 µm, branched but not anastomosing, lax, tips only slightly thickened, not much darkened; asci
8, biseriate, thin-walled, wall single, ellipsoid, often containing oil drops, walls K—, 30-65 X 16-36 µm.
Reactions: K—, C—, KC—, P—.
This species grows on moss, humus, and soil in the Arctic but also on tree trunks toward the southern edge of the range. It is circumpolar arctic-alpine; and boreal, and also occurs in the Andes in South America. In North America it ranges south to North Carolina, Minnesota, New Mexico, and California.