Verrucaria

Verrucaria is a genus of lichenized (lichen-forming) fungi in the family Verrucariaceae. These lichens form crust-like growths on rocks, particularly limestone and other calcareous surfaces, though some species also grow on siliceous rock or occasionally on bark and soil. The genus includes both terrestrial species found in dry environments and marine species that can survive periodic flooding or permanent submersion in coastal and freshwater habitats. With about 150 accepted species worldwide, Verrucaria represents a challenging taxonomic group due to overlapping physical characteristics and the polyphyletic nature of the genus.