English: A lichen - Ochrolechia parella. Although I submitted another photo of this species, the present image is of a typical specimen, while the other one (shown on red sandstone – 1042725) is not. This lichen was growing on one of the boulders of a dry-stone wall beside the road. It is often found growing on rocks alongside moss; it might be thought that the more rapidly-growing moss would soon grow over the lichen, but "species of Ochrolechia and Pertusaria are able to overgrow mosses and produce substances that inhibit the moss from overgrowing them" [George Baron in "Understanding Lichens].