Variation in thallus morphology in response to climatic and geographical distribution in an Usnea complex

Abstract

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.