Xanthoria parietina (L.) Beltr.
Common Orange Lichen
Very common bright orange lichen, but can be quite green when saturated or in shade. The abundant apothecia are orange with a lighter margin. Found on exposed coastal rocks but also on other substrates
Smith et al. editors (2009) The Lichens of Great Britain and Ireland
Dobson (2018) Lichens: an Illustrated Guide to the British and Irish Species