Description: This is lichen of hard, horizontal natural limestone, abundant in places like The Burren but also on limestone tombs in some of the older churchyards. The majority of the thallus — apart from specks of pale grey or fawn-grey, is buried in the rock with only the spherical discs visible (0.3-0.5mm diam.). These have a ‘sucked-in’ apex like little rubber tyres, showing clearly from above. Between the constellations of discs, black dots (pycnidia) may often be seen. Throughout Ireland; rare in the extreme south-east.

Key Identification Features:

• Thallus immersed, discs and dots (pycnidia) visible at the surface, speckled with fragments of grey or brown from below
• Discs with distinct sunken apex; hard limestone.

Original text submitted by Vince J. Giavarini

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

iNaturalist: Parabagliettoa dufourii at iNaturalist World Species Observations database.