Species: Protoblastenia rupestris
Photos: On roadside wall. Ballingeary, Cork, SW Ireland.
Scurfy or areolate greenish-brown or orange-grey thallus, can be +/- absent. Dull-orange apothecia with greenish tinge when wet, becoming convex and distorted. Apothecia not in pits.
Very common throughout Ireland on mortar, limestone and other calcareous substrata. Apothecia: K+ crimson
Similar: P. calva and P. incrustans. On hard, natural limestone.
Protoblastenia rupestris on wall. January 2009