Thallus foliose, lobate, loosely to closely attached, to 18 cm diam., corticolous. Lobes contiguous, undulate, sometimes imbricate, margins deeply crenate, subplacoid, slightly thickened, inrolling and often subascendent, ± densely phyllidiate-isidiate. Upper surface bright lettuce-green when wet, pale yellowish-brown to olive when dry, undulate, minutely rugose-plicate, roughened or obscurely ridged towards margins, distinctly phyllidiate, matt, lacking soredia, maculae or pseudocyphellae. Phyllidia mainly marginal at first, spreading to lamina, squamiform, rarely simple or terete, flattened, and ± dorsiventral. Medulla white, containing internal cephalodia visible as rounded swellings on lower surface. Lower surface pale yellowish-tan at margins, brown-black centrally, smooth and glabrous at margins with a short to thick, pale to dark tomentum towards centre, and clusters of black, stout, simple or squarrose rhizines (to 5 mm long), sometimes developed. Apothecia laminal, sessile, or subpedicellate, rather sparse, cupuliform, disc red-brown, to 4 mm diam., matt or shining, epruinose, imperforate, margins inflexed, coarsely rugulose-striate, becoming phyllidiate, thalline exciple yellow-brown, scabrid-areolate. Ascospores 8 per ascus, colourless or pale brownish, fusiform, 1-3(-7)-septate, 20-42 × 6-11 µm. Pycnidia occasional, immersed, visible as brownish globose swellings on upper surface, ostiole black, punctiform. Conidia straight, rod-shaped, 2-3 × 1 µm. Chemistry: Cortex K-; medulla K-, C+ red, KC+ red, Pd-. Gyrophoric acid.