Thompson, J., 1997. American Arctic Lichens: The Microlichens.
Thallus dark gray, olive, or dark brown, with a margin of radiate, discrete lobes which arc not contiguous, of serially formed, convex, chinkily separated or contiguous areolae; centrally the areolae are more contiguous; cortex transparent, but the upper part dark brown; hypothallus not distinct. Apothecia innate, to 0.5 mm broad; margin thick, prominent, either dark or of same color as thallus; thalloid margin 1-; disk concave, black, bare; hypothecium 1+ blue; epihymenium dark brown, with yellow mist in KOH; asci clavate; spores 8, ellipsoid, 12-17 x 7-8.5 µm. Conidia 8-22 x 0.6-0.7 µm.
Reactions: medulla K+ yellowish, C-, P-, I-.
This species grows on noncalcarcous rocks. It is circumpolar arctic, reported from Siberia, Novaya Zcmlya, Greenland. Alaska, and the Northwest Territories.