Thallus lobate, orbicular to spreading, large, 8-12 cm diam., loosely to closely attached, corticolous. Lobes rounded, undulate, 5-10 mm wide, margins entire, thin, slightly sinuous, ciliate, cilia to 1.5 mm, slender, numerous. Upper surface pale greenish-grey, smooth, matt, not shining or pruinose, very faintly maculate (×10 lens) at margins, becoming reticulate-cracked centrally, sorediate. Soralia marginal, short, linear, becoming convolute or slightly hooded on small, incised marginal laciniae, never recurved, soredia fine, granular, greyish-white, not becoming blackened. Lower surface smooth, black, with a wide, pale, naked marginal zone. Rhizines sparse, central, simple, black. Apothecia pedicellate, disc brown, to 3 mm diam., imperforate, margins entire, often sorediate, thalline exciple smooth and faintly maculate. Ascospores 18-22 × 8-10 µm. Chemistry: Cortex K+ yellow; medulla K-, C-, KC-, Pd+ red. Protocetraric acid and atranorin, occasionally usnic acid (tr.).