CITRONELLA (Cymbopogon nardus – Gramineae)
Citronella belongs to the same family of aromatic, oil-rich tropical grasses as lemongrass and palmarosa. These were once known by the generic name of Andropogon, but are now included in the genus Cymbopogon. There are a few varieties, but all are large, coarse and robust, growing to about 1.2-1.5 m (4-5 ft); they can grow wild at height, but are cultivated largely near the sea. They are propagated by root division, and the leaves are ready for cutting about eight months from planting, and thereafter about every four months, subject to weather. Replanting is necessary every four to five years.
The most esteemed of varieties come from Java, Sri Lanka, the Seychelles, New Guinea and Guyana. In 1933, it was estimated that 30,000 acres of Sri Lanka were given over to citronella production; in 1987, 100 – 120 tonnes of citronella oil were exported; but since then cultivation and production have diminished.
CITRONELLA ESSENTIAL OIL
Description: This is distilled from the leaves, and is yellow to dark brown with a very strong aromatic lemony smell. The production of oil varies from season to season.
The principal constituents: These vary depending on the origins of the oil. That from Java, for instance, is high in citronellol (30 -50 per cent) and geraniol, with traces of citral, methyl-eugenol and various terpenes. The oil from Sri Lanka contains less citronellol (only 8 -18 per cent), with some geraniol, 5 – 8 per cent eugenol, and traces of borneol, citral, and various terpenes.
Dangers: Because citronella oil is quite cheap, it has been used, along with sandalwood, to imitate geranium oil; withlemongrass and geranium to imitate rose (which contains geraniol and citronellol); and to imitate verbena.
For bites and to use as an insecticide, take a small bottle of citronella oil with you on holiday. Put a few drops on your bedding and next to your pillow. Apply to mosquito and other insect bites a few times a day: this will stop the itching and will act as an antiseptic as well. For children under eight years old, dilute the oil (10 drops in 25 ml/l fl oz almond oil).
If you have rheumatic problems or other aches and pains, mix 50 ml (2 fl oz) soya or other vegetable oil and 20 drops of citronella. Rub on the affected parts.
(See also stings and bites.)
Citronella oil is hardly used in therapy but because of its highly antiseptic and deodorizing properties, it is used a great deal in commercial preparations – soaps, cleaning products and insecticides. The citral content is utilized for the base of industrial menthol.