Isozyme Variation in Australian and South-African Populations of Emex australis Steinh

Isozyme variation was surveyed at 25 loci in 65 Australian (colonial) and 21 South African (native) populations of Emex australis. Only one polymorphism, restricted in distribution to the eastern States, was observed in Australia. Three additional polymorphisms were detected in South African populations, but most (16) South African populations were indistinguishable from the Australian ones. Thus, the relative uniformity of colonial populations of E. australis reflects the low level of isozyme variation in many populations within its native range.