Verrucariaceae Verrucaria dolosa Growth type crustose Chemical results negative Occurs on shaded siliceous rocks, limestona and concrete, often found on fragments The grey-green to brownish thallus is thin and superficial, continuous or patchy but not composed of distinct goniocysts. Spores (13)15-18(19) x (6)6.5-8(9) µm, the lower 2/3 often tapering. Microscope photograph below. Similar: V. murina occurs in similar habitats but has larger spores

Microscope photograph

Verrucaria dolosa
Portland and Lytchett Minster, Dorset. February, March and December 2016