Davidsonia pruriens aka Davidsonia Plum

Davidsonia pruriens is an Australian tree in the Cunoniaceae family. Its common names include Davidson's plum and Queensland itch tree. Kew lists its range from Queensland to northeastern New South Wales. Useful Tropical Plants gives Queensland as its range. It grows in several kinds of wet, primary rainforest. Its habitat extends from sea level to 3,281 feet [1,000 metres].

The tree has a slim form in its forest home. There, it can reach 33 feet [10 metres] in height. In open sites, it grows shorter and spreads more. Trees in these settings reach about 13–16 feet [4–5 metres]. Useful Tropical Plants also lists a height of 26 feet [8 metres]. The large leaves are a key feature in gardens. Each leaf can reach 3.3 feet [1 metre] or more. Young leaves emerge pink and bear soft hairs. These hairs can cause irritation despite their soft feel.

The dark purple fruit looks much like a plum. Each fruit measures about 0.16 feet [0.05 metres] across. The tree bears fruit in large clusters. A single cluster may hold more than 100 fruits. People gather the fruit from wild trees for local use. The pulp has a strong, sharp, sour taste. People eat it raw, though preserves and jellies are more usual uses. The evidence describes both raw and cooked uses of the fruit. These food uses need to be weighed against reported health risks.

Hydrogen cyanide has been reported in this species. Some people have had vomiting and upper stomach pain after eating its fruit. Its history as a food does not remove those concerns. The irritant hairs on new leaves pose a separate contact hazard. Both points matter when choosing a place for the tree. The supplied sources give no details about pests or diseases.

This tree grows in tropical and subtropical climates. Useful Tropical Plants reports tolerance of temperatures down to at least 32°F [0°C]. That report does not establish tolerance of colder conditions. Gardeners grow it as an ornamental as well as gathering its fruit. Its large leaves give it value as a foliage tree. Fresh seed can sprout within a few weeks of sowing.