THE EXPANDING DISTRIBUTIONS AND INVASIVENESS OF OENOTHERA IN SOUTHERNAFRICA

Dates and places of first collection and current distribution ranges o f taxa of Oenothera in southern Africa are determined and described in terms of modern political boundaries and biomes. These data are compa red with habitats in natural distribution ranges and historical events in southern Africa to attempt to explain why some species are more in vasive than others and how they were introduced to southern Africa. On the basis of current extent of distribution and rates of invasion, it is concluded that O. rosea L'Herit, O. stricta Ledeb. ex Link subsp. stricta and O. tetraptera Cav. as well as O. parodiana Munz subsp. par odiana and O. indecora Cambess. subsp. bonariensis Dietrich best fit t he category of invasive weeds.