Thallus orbicular or spreading over twigs to 8 cm diam., but generally smaller, lying flat on substrate or with suberect marginal lobes, corticolous or lignicolous. Lobes inflated, hollow, narrow 1-2(-3.5) mm wide, lobes somewhat broader within thallus 2-3(-4.5) mm, repeatedly dichotomously branched, crowded and contiguous, placodioid, rarely developing extended di- or trichotomously branched marginal lobes, divergent at axils and may lack lateral contacts, extended lobes may be digitate and flattened, or subterete and flattened at apices. Upper surface pale grey, shining, smooth, occasionally appearing black-margined through exposure of the lower surface. Medulla relatively thick, white. Lower surface black to brown-black, dull, strongly wrinkled, fading to pale brown or whitish at apices, occasionally with perforations at lobe apices. Apothecia common, small to medium, 1.5-6.5(-10) mm diam., short pedicellate, exciple weakly wrinkled, disc pale to reddish-brown and shining, concave, at maturity becoming darker brown, dull and ± flat, margin entire, narrow. Ascospores ellipsoid, 7-8.5 × 4-5.5 µm. Chemistry: Cortex K+ yellow; medulla KC+ red, Pd-. Atranorin, chloroatranorin, physodic, 3-hydroxyphysodic, 2'-O-methylphysodic and alectoronic acids.