Known only from west Donegal, the grey thallus of this rare species is easily confused with ‘bark pimple’ lichens belonging to groups such as Arthopyrenia and Eopyrenula. P. coryli has black cap over the perithecium (involucrellum) which spills out like a lava flow, and three-septate spores. Usually on hazel; algal partner apparently absent. Recent material of this species is urgently required.

Key characteristics

• Small, smooth bark species with grey thallus and perithecia (the size of Arthopyrenia fruits); involucrellum black, spreading
• Spores three-septate, on hazel.

Original text submitted by Vince J. Giavarini