Terminalia ferdinandiana, also called the gubinge, billygoat plum, Kakadu plum or murunga, is a flowering plant in the family Combretaceae, native to Australia, widespread throughout the tropical woodlands from northwestern Australia to eastern Arnhem Land.t has a high concentration of vitamin C in its fruit: recorded concentrations of 2300-3150 mg/100 g wet weight and occasionally as high as 5300 mg/100 g, compared with 50 mg/100 g for oranges, ranks among the highest known of any natural source.