Order: Verrucariales       Family: Verrucariaceae Species: Verrucaria halizoa Growth type crustose. Identification confirmed by John Douglass Photos: Coastal rocks, Allihies, Co. Cork, SW Ireland. Small patches of smooth, thin, olive-greenish (occasionally brown) thallus that becomes translucent when wet, occasionally with a thin black prothallus. The perithecia are +/- hemispherical, spores 8-11 x 3.5-5µm. Pycnidia are rare. Microscope photograph below. Coastal in sheltered crevices and on shady rocks in the mid-littoral (barnacle) zone. Often found among Verrucaria mucosa, Verrucaria striatula and the crustose red alga Hildenbrandia

Microscope photograph

Verrucaria halizoa . March 2012