Xanthoria parietina forms a conspicuous yellow band on sea cliffs where there are plenty of seabirds to provide the nitrogen that it loves. It is also found in other nitrogen rich habitat such as on trees and farm rooves and man-made substrates inland where the atmospheric nitrogen levels are high.Xanthoria parietina is found in nitrogen rich habitats .
Xanthoria is widespread over Britain, Europe and America but in tropical countries and in Australia it is rather rare. Its association with nitrogen and agricultural dust means that it has spread rapidly where man has cultivated the land and introduced stock, and since the clean-air acts it is now frequent in our cities.
Xanthoria parietina occurs with other lichen species in a distinctive lichen community which is named after it…the Xanthorion, and includes other species which are tolerant of nitrogen such as the grey-green Physcia.