A few days ago I visited an Agriculture Department station where they sell young fruit trees here in Fiji. I bought some robusta coffee, tea, cardamom, rambutan and langsat, but also bought two young trees of a mystery species.

The Ag guy called them a tropical "plum", and told me the fruit is not sweet but good for making jam or chutney. Photos below. What is it? I want to learn how much sun and water is best for them, how large they will grow, and other characteristics so I know where on the farm to plant them and how to care for them. Does anyone know this plant?




Thanks,
John

It appears to be Davidson plum, in the genus Davidsonia, family Cunoniaceae, so not even vaguely related to European plums. It's native to your end of the world, and as you say, is used in cooked products.

The tree also grows in Australia, about 3 species, and a few types of the Nth Qld spp. The fruit are fairly sour and look like purple plums, trees are very productive. When cooked with sugar, couldn't tell the difference from Prunus "blood plum" jam/sauce done the same way...very nice. The NSW species is a short multi trunk, the Qld one a tall umbrella shape. Another species is very rare , only 10 or 20 wild plants known in SE qld. It is also sterile/seedless, so has to be cutting propagated.

The Davidson plum's leaves reminds me somewhat of the Nanking Cherry. - Millet (373-ABO-)