Order: Arthoniales Family: Roccellaceae
Species: Opegrapha rupestris
Photos: Parasitic on Verrucaria. Black Head, the Burren, Ireland.
BLS Burren meeting 2009
Thallus barely visible. Scattered clusters of small lirellae, +/- rounded with persistently narrow central slit. Spores 3-septate.
Occurs as a parasite on crustose Verrucariaceae on natural limestone and memorials, especially Verrucaria baldensis. Recorded from northern and western Ireland.
Opegrapha rupestris. BLS Burren meeting, April 2009