Acacia aneura and its close relatives form a highly variable species complex commonly known as Mulga. They are small trees that dominate the vegetation of arid regions, in all occupying around 20% of Australia. Our research studies the phenotypic and genetic basis of the more important types variation found in Mulga, especially growth form and phyllode and pod morphology. This variation occurs both between and within populations and often results in a very complex mosaic of mixed Mulga populations. The underlying genetic and biological factors responsible for this variation are being explored and include hybridization, polyploidy, apomixis and neoteny. The major goal of the project is to generate taxonomic and genetic frameworks to better describe and name the phenotypic variation.