Thallus semi-immersed, smooth, continuous, somewhat cracked, pale white-grey. Soralia excavate, round, forming initially along cracks in the cortex or bursting through the thallus, quickly becoming confluent and irregular to form a leprose crust. Soredia farinose, 20-40 μm diam. but often aggregated into consoredia 60 μm or more across, pale grey-white, sometimes tinged yellow. Anamorph: no information available. Teleomorph: ascomata apothecia, very rare, similar to those of O. turneri, ca 1.3 mm diam., the thalline margins sorediate. Chemistry: cortex and soralia C+ yellow, K–, KC+ yellow, Pd–, UV+ white (variolaric and ± lichesterinic acid); apothecia variolaric (main), ± lichesterinic and gyrophoric acids.