Thallus closely attached, forming irregular patches among other lichens or encircling twigs. Lobes numerous, ± radiating towards outer edge, medium, (1-)2-3 mm wide, remaining almost distinct to centre of thallus or ± obliterated, branched, often with numerous toe-like laterals giving a sympodial appearance, compressed between main lobes, contiguous throughout entire length, often imbricate, becoming compressed-contorted centrally, margins sinuous-contorted, sparingly blackened at margins or whole upper surface ± blackened, or with black spots or lines, apices ± suffused-brown, hollow, lower side of internal cavity black, becoming grey or whitish towards tips. Upper surface convex, uniformly pale grey, emaculate, almost smooth or ± rugose-uneven, matt or shining, sorediate. Perforations frequent, median on main lobes, also on short laterals, small, 0.1-1.0 mm diam., ± elevated, ± conical, rounded, becoming ± ellipsoid. Soralia rather sparse, arising from edges of perforations, also scattered on surface or on short lateral lobes, ± efflorescent, becoming convex, ellipsoid or globular, farinose- or small granular-sorediate, to 2 mm diam., scattered or ± coalecsing. Apothecia rare, < 4 mm diam., sessile, margins persistent, crenulate-uneven, occasionally lacerate, disc smooth, ± shining, concave, red-brown, epruinose. Epithecium red-brown, densely granular, 20-25 µm thick. Ascospores 2 per ascus, 45-53 × 28-31 µm, wall c. 2 µm thick. Chemistry: Alectoronic and (-collatollic acids (UV+ ice-blue) and unknown UV-accessory substances; medulla K-, C-, KC+ pink, Pd-.