Caloplaca cerinella. This is like a minute form of Caloplaca cerina which grows on twigs. It should be searched for with a handlens. There is another very closely related species, Caloplaca cerinelloides, which can only be separated microscopically. The asci of C. cerinella contaiin between 8 and 16 spores, while C. cerinelloides always has eight spored asci. C. cerinelloides is especially found on twigs affected by limestone quarry dust. Note the size by comparing it with the lobes of Xanthoria parietina. the other minute lichen in the photo is Lecania cyrtella. This photograph was taken on twigs in Piddinghoe Churchyard, East Sussex.