Click here to view an interactive map of the Northern Ireland dataset as currently collated by CEDaR.
The map is generated through the NBN Gateway using their Interactive Mapping Tool.
On the north-facing surfaces of old limestone churches and ancient castle walls in warm, sheltered spots around Ireland, look for this species growing like a white-grey crust in small coalescing patches up to several centimetres wide. The grey crust is covered in a uniform dusting of powdery soredia so that it has a minutely speckled appearance. A fingernail dragged across the thallus should scratch orange. Discs are absent. Reactions: C+ rose-red, K-. Very thinly scattered in Ireland.
Original text submitted by Vince J. Giavarini