Molecular evidence that fireweed (Senecio madagascariensis, Asteraceae) isof South African origin

ITS1 sequence data was obtained for fireweed (Senecio madagascariensis) and S. lautus from Australia, S. madagascariensis and S. inaequidens from Sout h Africa and S. madagascariensis from Madagascar. Despite the low level of variation (0.0-3.4%), these data further resolve the controversy concerning the identity and origin of fireweed. They confirm that fireweed is part of the South African S. madagascariensis/S. inaequidens complex, and indicate that the infestation in Australia originated from South Africa as opposed to Madagascar. This will facilitate a resumption of biological control effo rts in Australia and will direct surveys for control agents to South Africa .