Family: Opegraphaceae Species: Opegrapha pertusariicola Lichenicolous fungus, photographs on Pertusaria hymenea Photos: Killarney NP, Co. Kerry, SW Ireland. Thallus absent but sometimes necrotic fawn-coloured patches visible on host thallus. Apothecia straight or slightly curved with +/- slit-like discs and a roughened margin. Exciple K+ green-black, epithecium brown. Asci 4-spored, spores (5-)6 septate, the median cell usually enlarged, 21-28 x 4.5-6 µm. Micrograph below. Usually occurs on Pertusaria leioplaca on Corylus but ocasionally also reported on P. hymenea and other corticolous Pertusaria's Similar: Opegrapha anomea occurs on Lepra species (Ochrolechiaceae), spores 17-26 × 6.5-9 µm, 3-septate

Micrograph

Opegrapha pertusariicola. August 2024