Description: Where farmland gives way to landscapes of hard, damp limestone, this species should be searched for. The thallus is almost non-existent: just a smear of pale grey can be seen, but the discs (0.5-1.5mm diam.) are quite unlike anything else on limestone – black, rounded in shape with a black raised rim — but also with a small black spot, pip or distortion in the centre, like the middle of a wheel. You would have to be scanning the limestone rock surface with a lens to notice. Predominantly north-west Ireland especially The Burren.

Key Identification Features:

• Black discs with a hard rim but also with a raised spot in the centre of some of the discs
• Hard, damp limestones.

Original text submitted by Vince J. Giavarini

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

iNaturalist: Farnoldia jurana at iNaturalist World Species Observations database.