Common Name: Camphor

General Information

Cinnamomum camphora is a relatively fast-growing, evergreen tree with a dense crown; it usually grows from 10 - 15 metres tall, but can reach 40 metres. The bole, which usually branches from quite low down, can be up to 75cm in diameter[, , ].
The plant is grown commercially in China and Japan as a medicinal tree and also for its essential oil, though most camphor oil on the market nowadays is produced synthetically[, ]. It has also been widely planted in other areas of the tropics, subtropics and warm temperate zones[]. At one time it was heavily exploited as a source of camphor, but the availability of cheap, synthetic camphor has meant that there is now only modest international demand for the natural form[]. Camphor produced from Cinnamon species is often considered superior to synthetic because the molecules are dextorotatory, whereas synthetic camphor (produced from pinene) contains both dextro- and laevorotatory forms and is considered by many Pharmocopoeias to be more toxic[].
Widely grown as a source of camphor and as an ornamental, this species has spread from cultivation. The fruits are a very popular food with several species of birds and these are generally blamed in Australia for the spread of this species. It is generally regarded as a pest species in northern New South Wales and south-east Queensland; and there is ample evidence that it is assuming a similar role on the Atherton Tableland, although it is not yet quite as obvious[].

Known Hazards

The plant is poisonous in large quantities[].
The essential oil and the wood can cause eye and skin irritation, whilst large doses of the essential oil can cause respiratory failure in children[].
See the report below on medicinal uses for more information.

Botanical References

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Range

E. Asia - China, Japan

Habitat

Banks of streams in China[], to elevations of 750 metres[]. Primary forest, occasionally in open areas, at elevations up to 3,000 metres but usually below 1,000 metres[].

Properties

Weed Potential	Yes
Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Evergreen Tree
Height	10.00 m
Growth Rate	Slow
Pollinators	Diptera
Cultivation Status	Cultivated, Ornamental, Wild

Cultivation Details

Cinnamomum camphora flourishes in warm temperate to subtropical climates, but also under tropical highland conditions[]. It requires hot summers to thrive[], and grows best in areas where the mean annual temperature is above 16°c[]. Mature trees can withstand occasional frosts with temperatures falling to about -5°c (-10°c according to another report[]), but young trees often succumb if temperatures fall below zero[]. In its natural habitat annual rainfall ranges between 1,000 - 3,500mm spread throughout the year; higher rainfall is tolerated only on free draining soils because the tree has a shallow root system and does not tolerate waterlogging[, ].
Succeeds in most soils[] but prefers a fertile sandy moisture-retentive well-drained soil in full sun or light part-day shade[]. Plants are tolerant of saline soils and salt-laden winds[]. Tolerates a pH in the range 4.3 to 8, but prefers a range from 6.5 - 8[].
Camphor is grown commercially in China and Japan as a medicinal tree and also for its essential oil[].
Camphor production should not start until trees are at least 20 years old[]. Yields of 2 - 3% of essential oil by steam distillation can be expected[].
Trees on lighter soils tend to have a higher essential oil content[]. In areas with very high rainfall or after prolonged periods of very heavy rain, the camphor content of the essential oil is low[]. Unshaded trees have the highest essential oil content[].
There are some named varieties, selected for their ornamental value[].
A very slow growing tree[]. The roots are very sensitive to disturbance[].

Edible Uses

Young shoots and leaves - cooked[, ]. Some caution is suggested because there is a report that the plant is poisonous in large quantities.

The old leaves are dried and used as a spice[, ].

An essential oil obtained from the plant is used as a food flavouring in baked goods, candy etc[].

Medicinal

Camphor has a long history of herbal use in the Orient with a wide range of uses. It has occasionally been used internally in the treatment of hysteria, but in modern day herbalism it is mainly used as the essential oil and internal use is not advised[].

The wood and leaves are analgesic, antispasmodic, odontalgic, rubefacient, stimulant. An infusion is used as an inhalant in the treatment of colds and diseases of the lungs[, , , , ].

The plant is more commonly used in the form of the essential oil which can be obtained by distillation of the chipped branches, trunk and wood of the tree, or from the leaves and twigs. Wood 24 - 40 years old is normally used[]. The essential oil is anthelmintic, antirheumatic, antispasmodic, cardiotonic, carminative, diaphoretic, sedative and tonic[, , , ]. It is used externally in liniments for treating joint and muscle pains, balms for chilblains, chapped lips, cold sores, skin diseases etc and as an inhalant for bronchial congestion[]. Some caution is advised, excessive use causes vomiting, palpitations, convulsions and death[]. It is possible that the oil can be absorbed through the skin, causing systemic poisoning[].

The essential oil is used in aromatherapy. Its keyword is 'Piercing'[]. It is used in the treatment of digestive complaints and depression[].

Other Uses

The essential oil obtained from camphor can vary quite considerably. On distillation, the wood from different groups of trees may yield camphor, linalool, safrole or cineole as the major chemical[].
The essential oil 'camphor' is obtained from the leaves and twigs[, , , , ]. It is extracted commercially by passing a current of steam through the wood chips, 30 kilos of wood yielding 1 kilo of camphor[]. Camphor is used medicinally, in perfumes, as an insecticide and also to make celluloid and as a wood preservative[, ]. It can also be put in shoes to cure perspiring feet[] (probably by acting as a deodorant rather than preventing perspiration[]).
Fractionation of the camphor-free oil obtained from the tree provides an oil rich in safrole (80% or more), usually called Chinese sassafras oil[].
The use of the tree as a source of leaf oil has expanded in recent years, and it is now an important source of natural linalool (which is still preferred over the synthetic form for some fragrant applications)[].

The wood has been burnt as a fumigant during epidemics[]. Its aroma helps to repel insects[].

The heartwood is brownish-yellow with a green cast, or olive to light olive-brown to blackish-brown; the sapwood is whitish or brownish. The texture is medium to coarse; the grain straight to roey; there is a satiny or silky lustre; the odour is spicy and acts to repel insects. The wood has excellent working qualities and takes a good polish. It is thought by many to be beautifully grained, though some people find it a bit garish. It is used for making furniture, cabinets, the interior finish of buildings etc[, , , , ].

Propagation

Seed - the seed has a short viability and is best sown as soon as it is ripe in a greenhouse[]. Remove the fruit pulp since this can inhibit germination[]. Germination can take 1 - 6 months at 20°c[]. Stored seed should be sown as soon as possible in a warm greenhouse[]. When they are large enough to handle, prick the seedlings out into individual pots and grow them on in a greenhouse for at least their first winter. Plant them out into their permanent positions in late spring or early summer, after the last expected frosts. Consider giving them some protection from the cold for at least their first two winters outdoors.
Cuttings of semi-ripe side shoots, 7cm with a heel, early summer/July in a frame with bottom heat[].