Thallus a pale- to dark-grey, cracked crust, initially with scattered greenish soralia but the whole thallus commonly becoming green-sorediate; apothecia small, black, concave to convex, when young with defined, more shiny, regular to convoluted margins.

On rocks, walls and stonework.

All year round.

Widespread and common in Britain.

Fairly frequent in Leicestershire and Rutland.