Description: This is a common, crustose, siliceous rock species regularly present in upland areas, especially near streams. It has compact, black apothecia (so flat they look ironed) and a smooth, cracked areolate, occasionally reddened thallus. A useful character is the brown colour of the discs when moist. It is generally scattered in Ireland, mainly in upland areas.

Key Identification Features:

• The key features are the abundant flat, black discs, smooth surface to the thallus and ‘ironed’ appearance. The black discs turn brown when moistened
• Loose rocks and boulders between the amphibious and terrestrial zones of upland acid streams usually provide plentiful material.

Original text submitted by Simon Davey

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

iNaturalist: Lecidea lithophila at iNaturalist World Species Observations database.