Lecanora expallens, present in the upper third of the image with a larger smooth expanse of L. orosthea below, growing on the side of a sandstone gravestone, VC 29, Cambridgeshire. Both species are rather common on the dry sides of sandstone memorials and may be confused. A spot reaction spans a junction between the two species where L. expallens is seen to be C+ orange and the thallus of L. orosthea has merely darkened green due to wetting. L. orosthea tends to produce slightly paler, more continuous smooth sheets of soredia while L. expallens tends to occur in more discontinuous patches. Lepraria incana is also present amongst the L. expallens as bluish coloured granules (e.g. top right).