The Burdekin plum (Pleiogynium timoriense) is a dark purple, plum-sized fruit of the cashew family (Anacardiaceae) native to northern and eastern Australia and nearby tropical Asia. Astringent and hard when picked, it must be softened for several days before it turns sweet-sour and edible — a long-valued food of Aboriginal Australians and a favourite of foraging birds and flying-foxes.