Thallus orbicular to 12 cm diam., but generally much smaller, corticolous. Lobes diverse in both width and separation, thalline margins of flattened, contiguous, placodioid lobes 2-4 mm wide, older lobes commonly contiguous, forming a compact, wrinkled or puckered thallus; central portions of younger thalli often of short, erect to suberect irregularly branched lobes, 1-2 mm wide, often also secondarily imbricate. Upper surface grey to whitish, wrinkled, upper cortex erupting and becoming sorediate, particularly near lobe apices and at surface wrinkles, ultimately extensively sorediate. Coralloid isidia commonly developed, becoming sorediate. Lower surface strongly wrinkled, glossy, black, pale brown at apices of young lobes. Apothecia very rare, disc reddish-brown, to 3 mm diam., subpedicellate, exciple funnel-shaped, sorediate, margins entire at first becoming sorediate. Ascospores 7-10 × 4-5 µm. Chemistry: Two chemodemes present in New Zealand material. Chemodeme (i): Cortex K+ yellow, medulla KC+ red, Pd-. Atranorin, chloroatranorin and the physodic acid complex. Chemodeme (ii): Cortex K+ yellow; medulla KC+ red, Pd+ red. Atranorin, chloroatranorin, physodic acid complex, physodalic acid and protocetraric ± acid.