Following on from my recent blog post about biological crusts, I was intrigued by the patterns formed by these lichens on the clay tiles capping the brick gate columns of our local cemetery. It looks as though they have been created by successive waves of growth, but I may be wrong about that. Any lichen experts out there who can tell me what’s going on?
I think the species is Xanthoria parietina, but again I’m happy to be corrected. Below is a cropped close-up from a slightly different angle.