THE MEDICINAL PROPERTIES AND BUSH FOODS OF EUCALYPTS

SCIENTIFIC NAME: Eucalyptus spp.
FAMILY: Myrtaceae

Did you know that one of the first plants used medicinally by the early British settlers was the 'Sydney peppermint', Eucalyptus piperita? Its crushed leaves emitted a peppermint odour, which was likened to the English peppermint, Mentha piperita. Steam distillation of its oil from the foliage was reputed to cure colic and intestinal disorders when taken in small quantities. Later scientific testing highlighted the lethal differences between the two plant species, with Mentha having high concentrations of menthol and menthone whilst the Eucalypt contained piperitone, which is more toxic than pure peppermint oil.

Both the Surgeon General to the Colony of New South Wales (John White) and the Surgeon of the First Fleet (Denis Considen) are credited with the Western 'discovery' (1788) of the medicinal properties of Eucalyptus piperita.

Traditional Aboriginal society used a wide range of Australian native plants as bush foods and medicines. Aborigines used several species of Eucalyptus as a tonic for gastro-intestinal symptoms, of which the peppermint gum was well-known. The gum when mixed with water was taken internally for diarrhoea, and in many reported instances as an infusion with tonic qualities. The properties of the locally-available Eucalyptus species afforded antiseptic, or astringent qualities, which were effective in treating wounds such as cuts and sores. For this reason also, many Eucalypt species were used in concocting mixtures for the relief of aches and pains of muscles, joints and even teeth. E. dives, (the broad-leaved peppermint of NSW and Victoria), was used in treating fevers, by burning the leaves and inhaling the smoke.

The River Red Gum (E. camaldulensis) which grows to 20m high in open woodland and 50m in dense forest appears in South Australia's riverine, floodplain and estuary systems. Because it is found in all southern mainland states it is the most widespread Eucalyptus species. It was prized by the Aboriginal inhabitants for its disinfecting qualities. The sap was collected, boiled in water until dissolved and then rubbed onto sores and cuts. Its heartwood, diluted with boiled water, was an effective treatment of diarrhoea in children.

The Lemon-scented Gum, (E. citriodora) which grows to 40m, was used as a natural insecticide, for troublesome mosquitoes. Where problems existed, branches would be stacked some distance from the camp. It was believed that the lemony smell of the citronella would attract mosquitoes, and hence keep them away from the main camp.

The bloodwoods were of enormous benefit too. The nectar from E. dichromophlaia, a tree which can vary in size from 2 to 10m. and found in the far North West zone of South Australia, was used as a remedy for coughs and coIds, and was often taken as a tonic. The gum when boiled with water and sugar, became a liquid drink used to treat pulmonary complaints, and as a general anaesthetic for toothache.

The exudate from E. gummifera (the Red Bloodwood), a medium tree to 30m found on the eastern coast of Australia, was used internally and applied externally in powdered form to treat sores. A poultice of mud and leaves was used to stop bleeding. E. polycarpa was applied as an antiseptic liquid in the treatment of sores, cuts, burns, ulcers and yaws, while E. terminalis, when diluted, provided a solution far the treatment of facial cuts and sores.

The Tasmanian Bluegum (E. globulus) was used in poultices and treatment of back conditions and rheumatism, inhaled for headaches, or drunk as an infusion to treat colds. The Coolibah (E. microtheca) found along waterways in the Far North and Far North West zone of the state was used to treat both snake bite and severe headache.

Resin was collected in crystallized and liquid form from damaged ghost gums (E. papuana), boiled and used as a powerful disinfectant in the treatment of cuts, sores, cramps and pain. An infusion of the bark was drunk for colds and as a wash for sore eyes. The Manna Gum (E. viminalis) a sub-coastal tree occurring in south eastern Australia and found in the Mount Lofty Ranges, the South East Zone and Kangaroo Island of South Australia prefers cooler, wetter areas (average rainfall 750mm). It, too, was useful in the treatment of opthalmia, and like most species so far, effective in treating diarrhoea. The leaves of this plant contain eucalyptol and tannin.

Stringybarks such as E. tetrodonta were used in a variety of ways. The young shoots were chewed for colds, crushed and placed on sores and cuts. Infusions were drunk for the relief of aches and pains, coughs, diarrhoea, and after childbirth. It was an effective antiseptic, like most Eucalypt species.

As far human survival, many of the Eucalypts' roots could be tapped for water. South Australian species of particular note include E. dumosa, a mallee or small tree found on Eyre and Yorke Peninsula, Central Districts, Murraylands and the South East; E. gracilis, the Yorrell, which occurs naturally in the mallee areas of the State; E. incrassata, the Ridge-fruited Mallee found growing on limestone-based soils and deep sands of the mallee regions; and E. oleosa, the widespread Red Mallee occurring in areas of low rainfall (averaging 200-400mm). Of particular note here is E. incrassata which could provide a litre of water from about 8 metres of root.

Species from other areas important as water sources include E. paniculata, the Grey Ironbark of coastal northern New South Wales; E. populnea, the Bimble Box of the Western Plains of New South Wales; E. transcontinentalis and E. uncinata.

As food sources, the seeds of the Blue Twin-leaved mallee of the Far North West Zone and Central Desert (E. gamophylla) were ground for damper, and its nectar drunk. The Cider Tree of Tasmania (E. gunnii) provided fresh sweet sap for drinking after holes were bored into the tree. If this was left too long, it became an intoxicating fermented drink.

The seeds and galls of the Central Australian Tammin mallee (E. leptopoda) were eaten. Other species from the area included the Coolabah (E. microtheca) which provided seeds which needed extensive preparation before use; the bloodwood (E. terminalis) which provided 'bush coconuts' (large galls and grub), nectar and native bee honeycombs; E. pachyphylla which provided nectar for drinking; and the Manna or ribbon gum (E. viminalis) which provided manna and lerp. This was collected during summer. The sugary substance was eaten raw or mixed with gum from Acacias and dissolved in water. Nine kilograms of manna could be collected from a single tree.

Today, these species are found in remaining vestiges of remnant vegetation or are grown for their beauty and particular qualities (shade, windbreaks, erosion control, landscaping, bird attracters, firewood and the like). They are in many instances unsuitable for urban dwellers because of the magnificent heights many of them can attain. One can only see them in rural areas, alongside roadsides, and in national parks, reserves and forests. It is hard to imagine in the growth of our nation, what the landscape looked like before settlement. However I am sure the sight would have been magnificent, even overpowering. As people today lean more and more towards sustainable agriculture, permaculture and self­sufficiency, traditional bush foods and their medicinal properties will become more pronounced.

Sources:
Boomsma,C. (1981) Native Trees of South Australia. Govt. Printer : Adelaide.

Costermans,L.(1991) Native Trees and Shrubs of South Eastern Australia. Weldon: Willoughby, NSW.

Isaacs,J. (1987) Bush Food. Ure Smith: Willoughby, NSW.

Lassak,E.and McCarthy, T.(1990) Australian Medicinal Plants. Mandarin Australia: Melbourne.

Christine A. Jones,
© 1993

DATE: February 1999

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