Thallus orbicular or confluent with other thalli, ± loosely attached, to 5 cm diam., corticolous, rarely saxicolous. Lobes variable, sometimes long and narrow, sometimes shorter and broader with long, terete, concolorous marginal cilia. Upper surface smooth, matt, greyish-blue to greenish-white. Soralia helmet-shaped, usually expanding on the underside forming rounded elevations visible from the upper side, soredia coarse, granular, white or greenish-white. Lower surface white to pale brown with sparse, blackened rhizines. Apothecia (not seen in New Zealand material) to 2 mm diam., disc often white-pruinose. Ascospores 16-23 × 7-10 µm. Pycnidia immersed. Conidia 4-6 × 1 µm. Chemistry: Cortex and medulla K+ yellow. Atranorin.