Chionanthus quadristamineus, commonly known as the blue plum, is a flowering plant in the olive family.

[1] Chionanthus quadristamineus is a pale-barked, evergreen tree, growing to 15 m in height.

The egg-shaped fruits are 5–6 cm long and dark blue when ripe.

[1][3][4] Chionanthus quadristamineus is endemic to Australia’s subtropical Lord Howe Island in the Tasman Sea.

It is common in forest from sea-level to elevations of about 400 m in the southern mountains of the island.