Volume 57 is the fifth volume of the Flora of Australia which documents the lichens. Here, we emphasise several speciose and ecologically significant families that colonise the bark of trees and shrubs in monsoon vine forest and in coastal and montane rainforest across northern Australia, viz. Graphidaceae, Phyllopsoraceae, Pyrenulaceae, Thelotremataceae and Trypetheliaceae. In addition, treatments are provided for prominent, mainly tropical and subtropical genera such as Dirinaria, Letrouitia, Pyxine and Strigula, as well as the more widely distributed Buellia s. str., Lepraria, Ramboldia and Tephromela. In contrast, the volume also includes lichens that are primarily associated with cool-temperate and montane habitats in south-eastern Australia, for example Nephroma, Peltigera, Thelocarpon and Umbilicaria. Complete or partial accounts of 21 families are provided in Volume 57, including 78 genera and 654 species and infra-specific taxa. One genus (Schizotrema, Thelotremataceae) and 27 species are described as new to science, and 35 new combinations are made. This work brings to 1822 the number of Australian lichen species and infra-specific taxa treated in the five volumes published.