Thallus foliose, lobate, dorsiventral, heteromerous, loosely to closely attached, ± rosette-forming to ribbon-like, corticolous, saxicolous or terricolous. Lobes linear or linear-cuneate to spathulate, branching ± dichotomous to irregular. Upper surface greyish to grey-white, or greenish-white, with or without pruina, with or without soralia, with or without squamules, rarely isidiate. Medulla white. Photobiont green, . Lower surface corticate or ecorticate, white, pale to dark greyish or often coloured with pigments, yellow-orange (K+ purple). Rhizines arising from lower-surface, white to black, simple to densely branched. Apothecia lecanorine, with a well-developed thalline exciple, disc brown or brown-black, epruinose, margins sometimes sorediate. Ascospores thick-walled, surface smooth, 1-septate, with or without sporoblastidia, dark brown.