Herb: Lemon-Scented Gum


Latin name: Eucalyptus citriodora


Synonyms: Eucalyptus maculata citriodora


Family: Myrtaceae (Myrtle Family)



Medicinal use of Lemon-Scented Gum:

Eucalyptus leaves are a traditional Aboriginal herbal remedy. The essential oil found in the leaves is a powerful antiseptic and is used all over the world for relieving coughs and colds, sore throats and other infections. The essential oil is a common ingredient in many over-the-counter cold remedies.An essential oil obtained from the leaves is antibacterial. The essential oil obtained from various species of eucalyptus is a very powerful antiseptic, especially when it is old, because ozone is formed in it on exposure to air. It has a decided disinfectant action, destroying the lower forms of life. The oil can be used externally, applied to cuts, skin infections etc, it can also be inhaled for treating blocked nasal passages, it can be gargled for sore throat and can also be taken internally for a wide range of complaints. Some caution is advised, however, because like all essential oils, it can have a deleterious effect on the body in larger doses. An oleo- resin is exuded from the tree. It can also be obtained from the tree by making incisions in the trunk. This resin contains tannin and is powerfully astringent, it is used internally in the treatment of diarrhoea and bladder inflammation, externally it is applied to cuts etc.

Description of the plant:



Plant:
Evergreen
Tree

Height:
45 m
(148 feet)

Flowering:
July to
August

Scent:
Scented
Tree

Habitat of the herb:

Usually found in heavy soils, but also succeeding on deep sandy loams in coastal regions.

Edible parts of Lemon-Scented Gum:

Produces a sweet manna-like substance that is scraped off the leaves and eaten.

Other uses of the herb:

A lemon-scented essential oil is obtained from the leaves. It is used, especially in perfumery but also medicinally. The leaves yield between 0.5 to 2.0% essential oil. This species is a very rich source of citronella, which is much used in the perfumery industry. Some batches of the essential oil contain 98% citronella. Glabrous leaves may contain oil with 65.5% citronellal, 12.2% citronellol, and 3.6% isopulegol, hairy leaves contain more oil with 86.6- 90.1% citronellal, 4.6 - 6.0% citronellol, and 0.7 - 0.8% isopulegol, 1-pinene, b-pinene, and isovaleric aldehyde are also recovered. The leaves and the essential oil are used as an insect repellent. The leaves are also an ingredient of pot-pourri. The bark may contain up to 12% tannin. The wood is good for saw-timber and is used for general construction, poles, railroad ties, and tool handles. Firewood yields run 10 - 21 m3/ha/yr. The hard heavy wood (sp. grav. 0.75 - 1.1) burns steadily and makes a good charcoal with an ash content of 1 - 2%.

Propagation of Lemon-Scented Gum:

Seed - surface sow February/March in a sunny position in a greenhouse. Species that come from high altitudes appreciate 6 - 8 weeks cold stratification at 2°C. Pot up the seedlings into individual pots as soon as the second set of seed leaves has developed, if left longer than this they might not move well. Plant out into their permanent positions in early summer and give them some protection from the cold in their first winter. The seed can also be sown in June, the young trees being planted in their final positions in late spring of the following year. The seed has a long viability.

Cultivation of the herb:

Usually found in heavy soils, but also succeeding on deep sandy loams in coastal regions.

Known hazards of Eucalyptus citriodora:

Citronellal, an essential oil found in most Eucalyptus species is reported to be mutagenic when used in isolation. In large doses, oil of eucalyptus, like so many essential oils has caused fatalities from intestinal irritation. Death is reported from ingestion of 4 - 24 ml of essential oils, but recoveries are also reported for the same amount. Symptoms include gastroenteric burning and irritation, nausea, vomiting, diarrhoea, oxygen deficiency, ,weakness, dizziness, stupor, difficult respiration, delirium, paralysis, convulsions, and death, usually due to respiratory failure.

Plant information taken from the Plants For A Future.