citriodora has smooth, pale, uniform or slightly mottled bark, white to coppery in summer, and a conspicuously narrow-leaved crown which smells strongly of lemons. Pear-shaped buds are borne in clusters of three, formed in the corner of leaf and stem junctions, whilst fruit (capsules) are urn-shaped. The bark is smooth for the entire height of the tree, often powdery, shedding in thin curling flakes.

The essential oil of the lemon-scented gum mainly consists of citronellal (80%),[4] produced largely in Brazil and China.[5] Unrefined oil from the lemon eucalyptus tree is used in perfumery, and a refined form of this oil is used in insect repellents, especially against mosquitoes. The refined oil’s citronellal content is turned into cis- and trans- isomers of p-menthane-3,8-diol (PMD), a process which occurs naturally as the eucalyptus leaves age. This refined oil, which includes related compounds from the essential corymbia citriodora, is known widely by its registered tradename, “Citriodiol”, but also by generic names which vary by region: “oil of lemon eucalyptus” or “OLE” (USA); “PMD rich botanic oil” or “PMDRBO” (Europe); “PMD and related oil of lemon eucalyptus compounds” (Canada); Extract of Lemon Eucalyptus (Australia). Pure PMD is synthesized for commercial production from synthetic citronellal.