Forms a cracking crust. It is dark brown to black, greener when wet.
On calcareous rocks, mortar, cement and stonework, including limestone memorials and gravestones.
All year round.
Widespread and fairly common in Britain.
Fairly frequent in Leicestershire and Rutland.
Leicestershire & Rutland Map
Enter a town or village to see local records
Yellow squares = NBN records (all known data)
Coloured circles = NatureSpot records: 2020+ | 2015-2019 | pre-2015