The Davidson Plum (sour plum) can be found in tropical rainforests in Queensland and northern NSW and are in season December through February..

This beautiful palm shaped tree has graceful fronds with fine hairy stems and on the underside of leaves. It produces clusters of large dark blue to black plums 4-5cm in diameter.
The dark red flesh contains two unusual flat seeds and has a wonderfully acidic plum flavour. The skin is thin but on the tougher, leathery side, and is covered with very fine hairs.

Freeze dried powder is available at Taste Australia Bush Food Shop
The powder is simply fabulous in biscuits, cakes, muffins. The whole fruit can be cooked into jams, syrups…. recipes here