Species: Lecanora actophila
Photos: On coastal rocks near Toormore, Cork, SW Ireland.
Creamy-white to yellowish grey-green smooth, cracked or areolate thallus, often with whitish prothallus. Small greenish-black, sessile apothecia become bluish when wet. Entire, paler margins become contorted but not excluded or crenulate.
K-, C-, KC+ weak yellow, P-, UV+ pale pink
Coastal, common on siliceous rocks in 'grey zone' above HWM.
Similar: Lecanora helicopsis. Greyer thallus, discs not pruinose.
Lecanora actophila. On coastal rock, Toormore, Co.Cork. February 2009