Lecanora confusa Almb.
Widespread, especially on smooth-barked trees. Very similar to L. symmicta. The thallus is yellow-grey to greenish, with a granular or granular-areolate surface. Apothecia have a yellowish disc with a pale, crenulate margin
Smith et al. editors (2009) The Lichens of Great Britain and Ireland
Dobson (2018) Lichens: an Illustrated Guide to the British and Irish Species