It is one of the crustose lichens of the Lecanoraceae family. The thallus is crustose, granular, rarely immersed in the substrate, whitish-yellowish, grayish-greenish, sometimes dark gray. The cortex is 25–50 µm thick, with more or less anticlinally arranged cells, filled with small, 1–1.5 µm wide, colorless crystals that do not dissolve in K and N. The medulla is white, filled with crystals 1–5 µm wide. Apothecia are common, lecanorine, 0.5–3 mm in diameter, initially broadly sessile, later becoming constricted at the base, brown to black, with an epruinose, slightly concave, convex disc and a thin, subcortical, slightly prominent, usually persistent thalline margin. The hymenium is colorless, 55–95 µm high, I+ blue, with simple or slightly branched paraphyses in the upper part. The hypothecium is colorless. Ascospores are 1-celled, hyaline, broadly ellipsoid, 9–16(–18) × 6–10 µm. Pycnidia are immersed, ovoid to subglobose. Conidia are filiform, straight or slightly curved. Color reactions: cortex — K+ pale to bright yellow, C–, KC+ yellow, P+ pale to bright yellow; medulla — K– or K+ pale yellow, P– or P+ pale yellow.
Chemical substances: atranorin, epanorin, zeorin, fatty acids, rarely traces of usnic acid.
Grows on base-rich, slightly siliceous rocks, sometimes on detritus, mosses, and other lichens (e.g., on Psora globifera).