Genus of evergreen trees of the Family Myrtaceae, having aromatic blue-grey leaves that yield a characteristic essential oil. Habit. Australia, cultivated in subtropical regions of Europe, Africa, Asia and U.S. More than 700 species are known; the Australian blue-gum, Eucalyptus globulus Labill., is the most predominant and said to be richest in essential oil. Constit. 0.5-3.5% volatile oil, resins, tannins, polyphenolic acids, and flavonoids such as quercetin, rutin, eucalyptin. Review of botany, cultivation and uses: M. Forrest, Biologist 47, 139-142 (2000); of pharmacology and medicinal uses: A. Y. Leung, S. Foster, Encyclopedia of Common Natural Ingredients, (Wiley-Interscience, Hoboken, 2nd Ed., 2003) pp 232-234; J. Gruenwald et al., PDR for Herbal Medicines (Medical Economics, Montvale, 3rd Ed., 2004) pp 293-297.
Obtained by steam distillation from fresh leaves of E. globulus. Constit. 70-80% Eucalyptol (1,8-cineole), α-pinene, d-limonene, p-cymene, α-phellandrene, 1-α-terpineol. Description: E. Guenther, The Essential Oils vol. 4 (van Nostrand, New York, 1950) pp 437-525.
Oil as expectorant, antiseptic, externally for rheumatism.