Widespread on exposed rocks, especially coastal. The thallus is light grey, crazed-areolate, with abundant black apothecia. Easily confused with Lecanora gangaleoides

References: 
Smith, C.W. et al. editors (2009) The Lichens of Great Britain and Irelandd
Dobson, F.S. (2018) Lichens: an Illustrated Guide to the British and Irish Species