The distribution of Avena species naturalized in Western Australia.
Wild oats (Avena spp.) were probably introduced into Western Australia from Tasmania c. 1830. Avena fatua and A. barbata now occur throughout the temperate areas of the state while A. sterilis is found in only a few isolated locations. A. fatua predominates in the drier and warmer north and north-east regions and A. barbata in the cooler and wetter south-west. A. fatua is found more commonly in cereal crops and A. barbata on road verges and undisturbed land. A. fatua occurs more commonly on fine-textured loams and A. barbata on coarse sands.