Thallus normally ± stiffly pendent, often long and straggling, to 30 cm long, juvenile specimens more erect and tufted, rigid, pale or blackened at the base, annular cracks abundant and conspicuous. Main branches coarse, to 1.5 mm diam., of uniform thickness, only tapering at apices, typically rather straight when well-developed or somewhat twisted, often ± angular; branching usually sparse, occasionally with numerous, irregularly arranged lateral branches, with scattered or sometimes abundant, single or clusters of thin fibrils to 1 cm in length arising at right-angles to branches. Surface dark grey-green, glossy and vitreous (glassy) in appearance, conspicuously and coarsely warted with numerous white, raised ± hemispherical tubercles, these often bursting to form coarsely granular, ulcerose soralia and occasionally isidiomorphs. Main branches also with smaller, low, translucent, paler papillae. Medulla very compact, pale to deep pink, rarely white.
Anamorph: not known.
Teleomorph: ascomata apothecia, rare, lateral on main branches, the disc with a few marginal fibrils.
Chemistry: thallus C+ yellow-orange, K–, CK+ yellow-orange, Pd– (diffractaic, barbatic and usnic acids and ± several accessory substances).