Thallus closely to loosely attached, orbicular to spreading 3-15 cm diam., saxicolous, or corticolous. Lobes sublinear-elongate, subdichotomously branched, rather narrow (to 10 mm wide), margins entire, sinuous. Upper surface pale greenish-grey to blackish-grey often with a distinctly bluish tinge, shining, not maculate, occasionally white-pruinose, wrinkled-faveolate, pseudocyphellae prominent, coarse, elongate and reticulate, soon becoming sorediate. Soredia derived from pseudocyphellae, in lines as a coarse reticulum, or becoming confluent. Lower surface black with little or no naked marginal zone, densely rhizinate. Rhizines black, simple to squarrosely branched. Apothecia and pycnidia not seen in New Zealand material. Chemistry: Cortex K+ yellow; medulla K+ yellow → red, C-, KC+ red, Pd+ orange. Salazinic acid and atranorin.