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Corymbia citriodora (Hook.) K.D.Hill & L.A.S.Johnson 1995
pronounced: kor-RIM-bee-uh sit-ree-oh-DOR-uh
(Myrtaceae – the gum family)
synonym: Eucalyptus citriodora Hook. 1848
pronounced: yoo-kuh-LIP-tuss sit-ree-oh-DOR-uh
common names: Lemon-scented Gum, Spotted Gum
Corymbia is from the Greek κορυμβος (korymbos), cluster, referring to the flowering habit. The genus was separated from Eucalyptus in 1995, and contains those gum trees whose flowers are borne in corymbs, flat-topped floral clusters with the outer flowers opening first. Citriodora is from the Latin citriodorus, lemon-scented.
This tree grows up to about 50 m tall, and is found north from Coffs Harbour (NSW) throughout coastal and montane eastern and central Queensland inland to Chinchilla, the Carnarvon Range, the Great Dividing Range east of Tambo, east from Townsville to Hughenden, and further north to Cooktown and Lakeland Downs in the Cape York Peninsula. It usually occurs as a component of dry sclerophyll forest in hilly country. As far as I know, it does not occur naturally on Magnetic Island. The young tree pictured has been planted in a bird and animal sanctuary in Horseshoe Bay.
The root system is lignotuberous. The tree has a smooth uniform to more-or-less mottled bark and a conspicuously narrow-leafed crown which, in northern populations, is strongly lemon-scented. The bark is often powdery, and is shed in thin curling flakes. Juvenile leaves are setose and have peltate leaf bases. Adult leaves are alternate, the petiole 1 – 2.5 cm long, the blade narrowly lanceolate to falcate, 10 – 23 cm long by 0.6 – 3 cm wide, the base tapering to the petiole.
Pyriform buds are borne in clusters of three, aggregated into compound inflorescences in the leaf axils, pedicels 1 – 6 mm long. The mature buds are obovoid to pyriform, green to creamy, usually smooth. The flowers are white.
There are two subspecies: ssp. citriodora from northern parts of the tree’s range, with narrow pendulous leaves, and pinkish bark; ssp. variegata from Maryborough south to Coffs Harbour, often with some mottling on the trunk, and lacking the lemon-scented leaf oils of ssp. citriodora.
This is an important forest tree, both for structural timber and for honey production. It is used as a plantation tree, and in some areas has spread from plantings and become naturalized, particularly in the Darling Range near Mundaring in Western Australia, and also in suburban Sydney. King’s Park, Perth, has a famous avenue of the trees planted many years ago, but the species has spread from there to become quite a serious weed.
The wood of the tree is quite dense. The heartwood is pale to dark brown or chocolate, and the sapwood distinctly paler. The texture is moderately coarse, and the grain variable: the frequent presence of wavy grain produces an attractive fiddleback figure. The wood is of a slightly greasy nature, and needs care in drying to reduce the risk of checking on tangential surfaces. The wood is not hard to work, and is satisfactory for steam bending if straight-grained material is selected. The unseasoned wood is slightly corrosive to aluminium nails and screws. It is used in heavy engineering construction, piles, poles, shipbuilding, agricultural machinery, flooring, decking and plywood, and for cabinet work. It is one of the main Australian species used for handles subject to high impact forces, such as axe handles.
The essential oil consists mainly of citronellal (80%). It is used in perfumery and in insect repellents.
Photographs taken in Horseshoe Bay 2014
Page last updated 2nd November 2016