Eucalyptus citriodora is an evergreen tree that grows rapidly and can reach heights of up to 50m tall. It originates from temperate and tropical eastern Australia, but is now grown in other parts of the world such as Brazil and China. It is also known as Corymbia citriodora which comes from the Latin citriodorus, meaning lemon-scented. It has a smooth or slightly mottled bark that is a white to coppery colour in season.
The refined essential oil that is steam distilled from this tree is the raw material used in Citriodiol®, and the unrefined version is extensively used in the perfume industry. The refined oil used for insect repellents has a very high citronellal content that is turned into cis- and trans- isomers of p-menthane-3,8-diol or PMD, a process that occurs naturally as the eucalyptus leaves age.