Description: Despite belonging to the same tribe as the ‘bark pimple’ species, this lichen is not an epiphyte and grows exclusively on limestone. The grey immersed thallus with tiny, brown, half-embedded spherical discs (perithecia) containing narrow, oblong, one-septate spores could only be confused with Porina linearis which has spindle-shaped, three-septate spores. It occurs mostly on shaded, hard limestones. County Clare (The Burren); thinly scattered in the north.

Key Identification Features:

• Dark brown perithecia containing oblong, one-septate spores
• Grows on hard, shaded limestone rocks and boulders.

Original text submitted by Vince J. Giavarini

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

iNaturalist: Naetrocymbe saxicola at iNaturalist World Species Observations database.