Thompson, J., 1997. American Arctic Lichens: The Microlichens.
Thallus gray, clay-ashy, not pruinosc, exceedingly thin, not radiate but partly fimbriate, chinky but not areolate; cortcx transparent, thin, ca. 25 µm; with pale hypothallus. Apothecia in prominent verrucae with vertical sides or slightly narrowed at base, to 0.5 mm broad, with a prominent wall formed by the verruca and of same color as thallus, giving a ring-like appearance; disk concave, black or brownish black when wet; hypothecium hyaline; epithecium brown, HC1+ green; hymenium 70-100 µm, 1+ blue, upper part brownish yellow; paraphyses fairly free in KOH, slender, rarely branched, upper part submoniliform, cells constricted at septum but elongate; spores 8, simple, hyaline, ellipsoid, 12-17 x 8-10 µm. Conidia not known.
Reactions: medulla K-, C-, P-, 1-.
This species grows on acid or calcareous rocks. It is known from Greenland and Alaska but is too rare to state a definite range.