Contemporary climate change is already having a marked impact on sub-Antarctic environments. If we are to conserve the unique plants of this region we need to better understand their potential to respond to these long-term changes. Our program takes a two-part approach combining macro- and micro-evolutionary studies to examine the origins and evolution of sub-Antarctic island plants and floras as well as how contemporary species interact with their environment. We propose interdisciplinary studies involving phylogenetics, cytogenetics, transcriptomics and analyses of trait variation across abiotic and biotic gradients. Combining insights into the history and current status of these plants will provide an unparalleled perspective on the potential for environmental change to shape plant diversity across a range of temporal and geographic scales.