There are about 50 genera of foliose lichens in New Zealand. Their appearance is that of a flat continuous thallus, attached to the substratum by some form of holdfast. The genus Sticta and the genus Parmelia are the largest, both in number of species and in size of plant body. There are over 50 species in each of these genera. Stictae are found mainly in the Southern Hemisphere. Among the larger species are S. coronata, S. flavicens, S. impressa, S. fovelata, and S. polychrita, all distinguished by pits on the lower surface.
Parmelias, somewhat similar in appearance, are black on the under surface. The genus Piltigera, found on damp earth, is represented in New Zealand by nine species. Like the four species of Nephroma, found on rocks and tree trunks, most of these are dark green on the upper surface and white below. Umbilicaria, eight species, are black and very small. Collema and Leptogium become gelatinous when damp. The large yellow-orange Xanthoria is found on trees and rocks near the sea.