Thallus loosely attached, rosette-forming, 3-5(-8) cm diam., corticolous. Lobes convex, 0.5-1.0 mm wide, conspicuously constricted at branch points, branching dichotomous towards apices, ± densely imbricate centrally, margins entire, apices narrow, incised. Upper surface pale to bright yellow (usnic acid) smooth, glossy at apices, without soredia, maculae or pseudocyphellae, densely papillate-isidiate in older parts. Isidia simple, nodular, rather fragile, slightly expanded at tips, often densely crowded over whole upper surface and at lobe margins, rarely becoming coralloid-branched centrally. Lower cortex yellow, matt, smooth, visible at apices of lobes and between patches of hypothallus. Hypothallus spongy, compact, less than 1 mm thick, dark brown to black, moniliform. Rhizines common, black, simple or sparingly branched with an anchoring apical tuft. Apothecia rare, small, 3 mm diam., sessile. Margins distinctly isidiate, concolorous with thallus, disc smooth, imperforate, red-brown, thalline exciple wrinkled, isidiate, lacking tomentum. Pycnidia laminal, scattered, punctiform, black.