Eucalyptus, Australia importance

Eucalyptus oils are produced from plants belonging to the genus Eucalyptus (Myrtaceae), which includes ca. 500 species in Australia, the country of origin, alone. Correct botanical classification was possible only by determining the chemical composition of the essential oils obtained from the leaves. At present, few of these oils are commercially important. 

Eucalyptus citriodora Hook f (Lemon gum) The oil of the fresh leaves of E. citriodora (2.2-8.3%), a tree introduced into Kenya from Australia (68), has been well researched in Kenya. Results indicate that there are two chemical varieties that were introduced. The chief essential oil constituents of one variety are citronellal (65-88%), citronellol (2-25%) and isopulegol (2-19%). In constrast, the second variety has as its major essential oil consitutents citronellol (32-52%), citronellal (38-59%) and 1,8-cineole (2-19%) (68,69). The essential oil is regarded as a perfumery oil. This plant is the second most commercially important Eucalyptus species in the essential oil trade and is only second to E. smithii Baker (69). The aromatic oil is used in soaps, creams and lotions due to its desirable odor properties, and as with many other essential oils is also used extensively in many technical preparations to mask other industrial malodors. A highly active mosquito repellent compound, p-menthane 3,8-diol has been isolated from the waste water of distillation of E. citriodora. There are now many commercial mosquito repellents based on this waste water (70-73). 

Derivation By fractionally distilling eucalyptus oil followed by freezing. The oil is imported from Spain, Portugal, and Australia. 

The purple sage of southern California is another example, as is the eucalyptus tree, an import from Australia. The common chrysanthemum is allelopathic, even unto its own kind. 

Eucalyptus Ohs. E. mostly occur as by-products in the treatment of eucalyptus trees cultivated for the production of wood, paper, cellulose, charcoal, etc. llie total area world-wide used for the cultivation of eucalyptus plants is estimated as 6,000,000 ha. With over 600 species, originally endemic to Australia and Tasmania, Eucalyptus is now grown in all warmer regions of the world. The commercially important essential oils obtained from Eucalyptus plants are ... 

Eucalyptus oil is produced principally in Australia and Tasmania, which practically supply the world s requirements. Small amounts are distilled elsewhere, as in Algeria, the South of France, Italy, Portugal, the Transvaal, Mexico, etc., etc., but commercially they are of little importance. 

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