Backhousia citriodora (Lemon Myrtle, Lemon Scented Myrtle) is a flowering plant in the family Myrtaceae, genus Backhousia, native to the semi-temperate rainforests of eastern Australia. It is often mistakenly called "lemon ironbark", which is actually Eucalyptus staigeriana. Other common names are Sweet Verbena Tree, Sweet Verbena Myrtle, Lemon scented Verbena, and Lemon scented Backhousia.
It can reach 20 m in height, but is often smaller. The leaves are evergreen, opposite, lanceolate, 5-12 cm long and 1.5-2.5 cm broad, glossy green, with an entire margin. The flowers are creamy-white, 5-7 mm diameter, produced in clusters at the ends of the branches from summer through to autumn, after petal fall the calyx is persistent.
Lemon myrtle was given the botanical name Backhousia citriodora in 1853 after the English botanist, James Backhouse. The common name reflects the strong lemon smell of the crushed leaves.
B.citriodora has two chemotypes. The citral chemotype is more prevalent and is cultivated in Australia for flavouring and essential oil. The other citronellal chemotype is uncommon.