The morphological, anatomical and chemical characteristics of five taxa of Usnea (e.g.U. scabrida, U. elegans, U. molliuscula, U. queenslandica and U.ramulosissima), which belong to the U. scabrida- U. molliuscula complex are described.Usnea scabrida subsp. tayloriana is described as new. Usnea elegans and U.queenslandica are reduced to subspecies: U. scabrida subsp.elegans and U. molliuscula subsp. queenslandica. The species U. consimilis Stirton is considered synonymous with U. scabrida. A canonical discriminant analysis of geographic and climatic data was undertaken, which demonstrated that the species under investigation generally occupied discrete non-overlapping zones, indicating that the differences in thallus morphology correlated with particular climatic regions.