Peltula

Peltula is a genus of small dark brown to olive or dark gray squamulose lichens that can be saxicolous (grow on rock)) or terricolous (grow on soil). Members of the genus are commonly called rock-olive lichens. They are cyanolichens, with the cyanobacterium photobiont being from the Anacystis genus. They are umbillicate with flat to erect squamule lobes that attach from a central holdfast or cluster of rhizenes. Lichen spot tests are usually negative.