Description: This is a lichen of smooth-topped, nutrient-enriched acid rocks in the uplands; also drystone walls and old brick walls in towns. The thallus is cracked like dry mud into numerous, red-brown pieces (areoles), the whole surrounded by a black line (prothallus). The glazed-over black discs are sunken into the areoles, so lie flat on the surface. It is common on suitable habitats throughout Ireland. A dab of fresh bleach can turn the thallus red.

Key Identification Features:

• The cracked, lizard-skin-like areolate thallus that is pale red-brown with a black prothallus helps to identify this species
• The frosted-over discs are immersed in the thallus that reacts C + red.

Original text submitted by Simon Davey

Distribution Map from NBN: Lecidea fuscoatra s. lat. at National Biodiversity Network mapping facility, data for UK.

iNaturalist: Lecidea fuscoatra s. lat. at iNaturalist World Species Observations database.