The lemon-scented gum has the botanical name of Corymbia citriodora or Euchalyptus citriodora. It may also be known as the blue spotted gum or lemon eucalyptus. The name comes from the strong lemon perfume of the foliage. It is a tall tree from the temperate and tropical regions of eastern Australia. It has been very successfully cultivated in Western Australia where there is an outstanding avenue of lemon-scented gums in Kings Park in the state’s capital, Perth. It is a popular ornamental species for gardens and parks although it has lost favour in recent years through its habit of dropping limbs without warning. It has a statuesque appearance and a pleasant perfume.
Coymbia citrodora has smooth, pale bark which may be slightly mottled and white to coppery coloured in summer. The bark is often powdery and shed in thin curling flakes. The entire trunk and branches are smooth and light in colour, producing a most attractive appearance. The leaves are narrow and the pear-shaped buds are carried in clusters of three appearing at the leaf and stem junctions. The fruit capsules are the shape of an urn.
The lemon-scented gum prefers loamy soils which are slightly on the acidic side. Under natural conditions it occurs in dry sclerophyll forest and hilly woodlands. It is found in northern Queensland from Atherton to Maryborough but is also a favourite with home gardeners and does well in more temperature climates.
It is one of the eucalypts that has a lignotuber – a starchy swelling of the root crown. The lignotuber is a protection against the destruction of the tree by fire. The main purpose of the lignotuber is to provide buds (and sufficient nutrients to support the growth of the buds) after devastating bushfires. Most mallees, many banksias and some other eucalypts such as Eucalyptus marginata or jarrah also have lignotubers.
The lemon-scented gum is a fast growing tree with a smooth, straight white trunk. The crown is open and the leaves are narrow and lance-shaped. The buds are a pale green before opening to become creamy white flowers. The tree has been known to flower in most months of the year although winter is the most common. It is a fast growing tree reaching 20 to 30 metres high at maturity. They prefer full sun and well-drained soil and need to be protected from frost until they are somewhat established. Once established, it is drought tolerant. It has a strong root system and should be planted well away from underground pipes and building foundations. It is used for structural timber and essential oils. The oil, citronella, is used in perfumes and, in a concentrated form, in insect repellents. The tree is one of those preferred by apiarists as nectar for commercial honey production.