Chionanthus quadristamineusChionanthus quadristamineus, commonly known as the blue plum, is a flowering plant in the olive family. The specific epithet refers to the four stamens in the flowers.DescriptionChionanthus quadristamineus is a pale-barked, evergreen tree, growing to 15 m in height. The leathery, broadly elliptic to narrowly obovate leaves are 5–12 cm long and 3–6 cm wide. The small green flowers are 5 mm in diameter. The egg-shaped fruits are 5–6 cm long and dark blue when ripe. The flowering season is from November to May.Distribution and habitatChionanthus 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.