The seedplant flora growing above 1000 m on Mt Field was studied. Greater colonist ability, and larger and lower altitudinal ranges, were found to a significant degree in alien than in native species; in species belonging to genera growing also in the northern hemisphere than in more restricted genera; and in more widespread species than in Tasmanian endemic species. These results suggest that ecological characteristics favouring long distance migration are partly retained by younger floristic elements, and that the deri- vation of Australia's alpine flora is complex and partly only Quaternary in age.