Thin, greenish, pale to orange-grey, or grey-brown, areolate thallus. Apothecia pale to deep orange, often strongly convex. Extremely common and widespread on rocks, concrete and even asphalt

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