Vachellia xanthophloea is often observed as a garden ornamental tree in gardens in towns and lodges throughout Namibia. Escapee plants were observed along the Orange River between Komsberg and Sendelingsdrift in southern Namibia and have insidiously invaded the riparian habitat without notice. It is viewed as a native–alien population and may detrimentally affect the local riparian ecology, therefore recommended that eradication be implemented immediately. Keywords: fever tree, Namibia, native-alien population, Orange River, Vachellia xanthophloea.