Thallus spreading, to 10 cm diam., loosely attached, corticolous. Lobes variable, often rather narrow (2-5 mm wide) and elongate, to short and rounded-imbricate, dichotomously to irregularly branched, often clustered, imbricate centrally, apices blunt, pointed or rounded, margins entire, often devoid of algae in a narrow, white band. Upper surface greenish-grey (often bluish-green in deep shade) smooth, shining, rather thin and fragile when dry, often maculate at margins and apices, pseudocyphellae not well-developed, mainly marginal, small, sparse and scattered. Lower surface black, wrinkled or smooth, shining, densely rhizinate. Rhizines black, squarrosely branched, often protruding beyond margins. Apothecia frequent, pedicellate, small (2-4 mm diam.), to large and lacerate-expanded (to 20 mm diam.), disc brown, pale and often maculate in shaded specimens, imperforate, margins entire to crenate-incised, thalline exciple strongly wrinkled to corrugate-verrucose and maculate, rather scabrid, often lacking algae, concolorous with thallus. Ascospores ellipsoid, 13-18 × 8.5-11 µm. Pycnidia numerous, scattered, reddish-black, immersed, punctiform. Chemistry: Chemodeme i: Cortex K+ yellow; medulla K+ yellow → red, C-, KC+ red, Pd+ orange. Salazinic acid and atranorin. Chemodeme ii: Cortex K+ yellow; medulla K+ yellow, C-, KC+ pink, Pd+ orange. Protocetraric acid, atranorin and an unidentified compound. Chemodeme iii: Echinocarpic acid and atranorin. Chemodeme iv: Atranorin. In addition, occasional specimens appear to be "hybrids" with mixed chemical constituents.