Thallus lobate, rather small, 2-7 cm diam., loosely attached, corticolous, rarely saxicolous. Lobes narrow, 2-3 mm wide, dichotomously branched, subascendant apically, margins entire, black and shining, axils sinuous. Upper surface yellowish-green (usnic acid), smooth, shining, without maculae or isidia, sorediate. Soralia terminal or subterminal, capitate, often recurved, soredia fine, powdery, pale yellowish at first, becoming blackened with age. Lower surface black, shining, minutely wrinkled, often pale brown at tips, densely rhizinate. Rhizines black, long, squarrosely branched, extending beyond lobe margins in a dense mat. Apothecia not seen. Chemistry: Cortex K+ yellow; medulla K+ yellow-red, C-, KC+ red, Pd+ orange. Salazinic, norstictic and usnic acids and atranorin.