Family: Lecanoraceae
Lecanora pulicaris (Pers.) Ach.
Type: Crustose
A common species of acid bark. Very similar to Lecanora chlarotera but that species lacks a prothallus
References:
Smith, C.W. et al. editors (2009) The Lichens of Great Britain and Irelandd
Whelan (2011) Lichens of Ireland