Calicium corynellum

Calicium corynellum
©Fred Rumsey

This lichen has a pale green crust and black fruits that resemble pin heads.

For many years it was restricted to a few stones on the wall of a single church in Northumberland and was under serious threat at one point, when some minor building works caused a decrease in the level of dampness on the wall.

Remedial work has now been undertaken but the lichen has not been seen at the site for three years and may have been lost. Fortunately two new sites in Northumberland have recently been discovered, where larger populations occur on some of the gravestones.