Eucalyptus Citriodora Essential Oil
The essential oil derived from the leaves of this species is known in aromatherapy as both lemon eucalyptus as well as by its botanical name ofEucalyptus citriodora. Although this essential oil is not as popular in aromatherapy as the ubiquitousEucalyptus globulus, it is fast growing in reputation due to its powerful bactericidal properties.
Commonly known as the lemon scented gum tree and blue spotted gum tree in its native country, Eucalyptus citriodora is a fast-growing stately evergreen growing 25 to 40 metres high, sometimes reaching 50 metres (165 ft) when growing wild. It has a variable form but typically presents a sparse, pendulous crown of narrow lanceolate leaves that are strongly lemon-scented.
Although large quantities of eucalyptus citriodora essential oil were distilled in Queensland during the 1950’s and 1960’s, very little of this oil is produced in Australia today. The largest producing countries are now Brazil, China and India, with smaller quantities originating from South Africa, Guatemala, Madagascar, Morocco and Russia.
All species of eucalyptus leaves have been used in traditional Aboriginal bush medicine for thousands of years. Infusions made of E. citriodora leaves were taken internally to reduce fevers and ease gastric conditions, and applied externally as a wash for the analgesic, anti-fungal and anti-inflammatory properties. Aborigines would make leaves into a poultice and apply them to ease joint pain and speed up the healing of cuts, skin conditions, wounds and infections.
Respiratory infections, colds and sinus congestion were treated by inhaling the vapours of steamed leaves, and to treat rheumatism the leaves were made into beds or used in steam pits heated by fire. The therapeutic qualities of the leaves and its essential oil were eventually introduced and integrated into many traditional medicine systems, including Chinese, Indian Ayurvedic and Greco-European.
Harvesting and extraction
In Brazil, leaf harvesting may take place twice a year, whereas most of the oil produced in India comes from smallholders who harvest leaves at irregular times, mostly depending on convenience, demand, and oil trading prices.
After collection, the leaves, stems and twigs are sometimes chipped before quickly loading into the still for extraction by steam distillation. The odour is very fresh, lemon-citrus and somewhat reminiscent of citronella oil (Cymbopogon nardus), due to the fact that both oils contain high levels of the monoterpene aldehyde, citronellal.
Uses in aromatherapy
Eucalyptus citriodora essential oil is powerful fungicidal and bactericidal, and a valuable asset when treating athletes foot. It is also effective against a wide range of respiratory conditions such as asthma, sinusitis, phlegm, coughs and colds, as well easing sore throats and laryngitis. Vaporized, lemon eucalyptus oil has a reviving and refreshing action that uplifts, yet is also calming to the mind.
Eucalyptus lemon oil is a powerful fungicidal and bactericidal that has been scientifically evaluated many times against a wide range of organisms. In 2007, the antibacterial activity of Eucalyptus citriodora essential oil was tested against a battery of clinically important bacterial strains at the Phytochemical Pharmacological and Microbiological Laboratory in India, and was found to be highly active against Alcaligenes fecalis and Proteus mirabilis,and active against Staphylococcus aureus, Escherichia coli, Proteus vulgaris, Salmonella typhimurium, Enterobacter aerogenes, Pseudomonas testosterone, Bacillus cereus, Citrobacter freundii. Its efficacy was found to be comparable to the antibiotics Piperacillin and Amikacin.
Lemon-scented eucalyptus oil is a top note and blends well with basil, cedarwood virginian, clary sage, coriander, juniper berry, lavender, marjoram, melissa, peppermint, pine, rosemary, thyme and vetiver. In natural perfumery it can be used successfully to add a fresh, slightly citrusy-floral top note to blends.