Description: This epiphytic crustose lichen is virtually unknown outside Ireland where it is, locally frequent. The thick, shiny, yellow-green to rusty-orange thallus contains numerous sunken spherical discs (perithecia) visible at the surface only as pinprick-sized pores. It has been recorded from holly, beech, hawthorn and rowan. The species is strongly oceanic and has its headquarters in the Killarney Woods in County Kerry. Its distribution extends up the west coast to Glenveagh in west Donegal.

Key Identification Features:

• Unlike other Pyrenula species P. dermatodes has its discs sunk below the surface of the thallus only visible as black, pinprick-sized dots
• On smooth-barked trees the giveaway clue is the yellow to rusty-orange coloured thallus.

Original text submitted by Vince J. Giavarini

Distribution Map from NBN: Pyrenula dermatodes at National Biodiversity Network mapping facility, data for UK.

iNaturalist: Pyrenula dermatodes at iNaturalist World Species Observations database.