Description: Thallus crustose, usually verrucose, rarely almost endosubstratic, intensely yellowish green. Cortex with numerous small yellowish green crystals. Apothecia immersed in the warts, epruinose, 0.4-1 mm across. Exciple uniformly thin throughout, blackish brown, of sclerotized, strongly intertwined hyphae with thickened walls; mazaedium black, epruinose; hypothecium pale to medium brown. Asci pyriform, dissolving early, with 2-3-seriate ascospores. Ascospores 1-septate and constricted at septum, brown, broadly ellipsoid, 17-22 x 6-7 µm, with a smooth surface. Pycnidia at first spherical to ellipsoid, later confluent and forming irregular, up to 0.4 mm wide aggregates. Conidia 1-celled, hyaline, ellipsoid, 3-4 x c. 1.5 µm. Spot tests: thallus K-, C-, KC-, P-. Chemistry: thallus with rhizocarpic acid, epanorin and two unidentified substances.
Note: a mainly boreal-montane, circumpolar lichen found in upland areas on hard, dry wood, especially of conifers, on wooden fences and fence-posts, often together with Ramboldia elabens.