Also called ‘Black-eyed Lichen’, it is a crustose, warty lichen, pale grey in colour with distinctive disc-like black fruiting bodies, each with a raised, pale grey rim. Thallus 10cm in diameter. Fruiting body 3mm wide.
Found well-lit coastal rocks in the splash zone, on seabird perches such as cliffs, and stone walls inland. Rarely found on trees. Common and widespread throughout the British Isles.