Common Name: Gutta-Percha

General Information

Eucommia ulmoides is a deciduous tree with a broadly-domed crown; it can grow up to 20 metres tall and 15 metres wide. The bole can be 50cm in diameter[].
The tree is harvested from the wild for use as a medicine and source of materials. It is an economically important plant in China, being utilized for herbal medicine and the organic chemical industry, and is also cultivated in Korea and Vietnam[].
Although it is widely cultivated, Eucommia ulmoides has become a rare species in the wild, known from scattered subpopulations. The population size is thought to be fewer than 1,000 mature individuals. The main threat to this species is over-exploitation across its natural range and
coupled with high deforestation rates the species is of conservation concern. The plant is classified as 'Vulnerable' in the IUCN Red List of Threatened Species(2013)[].

Known Hazards

None known

Botanical References

Range

E. Asia - central and southern China.

Habitat

Mixed forests, sparse forests, thickets, lower mountains, ridges, valleys, dry ravines, fields, also widely cultivated and locally becoming naturalized; at elevations from 100 - 2,000 metres[].

Properties

Conservation Status	Vulnerable
Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Deciduous Tree
Height	12.00 m
Growth Rate
Pollinators	Wind
Self-fertile	No
Cultivation Status	Cultivated, Wild

Cultivation Details

Eucommia ulmoides is native to the temperate zone in the mountainous regions of central and southern China, where it can be found at elevations up to 2,000 metres. A very cold-tolerant tree, when fully dormant it can withstand temperatures down to about -20 to -25°c[, ].
Succeeds in any well-drained moisture retentive soil in full sun with shelter from cold winds[]. Prefers a good loamy soil[]. The tree is adapted to a high soil pH[].Established plants are very drought tolerant[].
A fast growing tree[]. A moderately slow-growing tree[].
This species is commonly cultivated in Russia and China, both for gutta percha and for the medicinal used of the stembark[, ]. By using different solvents it is possible to obtain both of these products and the residue is then used for energy production[].
The bark is peeled in spring or early summer, from about 10 - 20-year-old trees, at least 15cm in diameter. Care should be taken not to girdle the tree; preferably a third of the bark should be spared[].
Three to four year-old plantations for gutta-percha production yield 200 - 250 kilos of gutta-percha per hectare[]..
This species is the only hardy rubber tree that can be grown outdoors in Britain[].
Dioecious. Male and female plants must be grown if seed is required.

Edible Uses

Young leaves[]. The leaves are used as the basis for beverages[].

Medicinal

Gutta-percha, known as Du Zhong in China, is commonly used in Chinese herbalism, where it is considered to be one of the 50 fundamental herbs[]. It is considered to be an excellent tonic for the kidneys and liver, and is thought to act specifically on the lower part of the body[].
Much interest has been aroused by Du Zhong's ability to reduce high blood pressure. In a clinical trial involving 119 people, 46% of those treated with the herb showed a significant reduction in blood pressure[]. However, it seems to have little effect in cases of severe hypertension[].
The plant has also been shown to be a promising agent in the treatment of osteoporosis[].

The stem bark is analgesic, anticholesterolemic, antiinflammatory, antimicrobial, antioxidant, aphrodisiac, cardiac, depurative, diuretic, hepatic, hypotensive, nervine, sedative, tonic and vasodilator[, , , , , , , ]. Its use lowers blood pressure (the stir-fried bark is stronger than raw and a decoction is stronger than a tincture) and reduces the absorption of cholesterol[]. It is used in the treatment of impotence, frequent urination, lumbago, weakness of the lower part of the body, aching back and knees, hypertension and threatened abortion[, ].
The bark is separated from the tree in summer, pressed flat then left in heaps for 6 - 7 days until the internal surface takes on a blackish tinge. It is then dried for later use[]

The flowers and the fruit are astringent[].

Other Uses

A rubber is obtained from the sap, but not in commercially viable quantities[, , ].
The leaves contain 3% dry weight of gutta-percha, a non-elastic rubber, used for lining pipes, insulating electrical cables, filling teeth etc[, ]. The gutta-percha is found in all parts of the tree and is extracted by alcohol[, ].

An extract of the bark is used as an ingredient in commercial cosmetic preparations as an antioxidant and skin protector[].

The wood is used for furniture making[], and to make Pattens (a type of shoe with raised soles)[].
The wood is used for fuel[].

Propagation

Seed - best sown as soon as it is ripe in a cold frame. Stratify stored seed for 3 months at 2°c[]. Germination is usually good and takes place in the first spring[]. When they are large enough to handle, prick the seedlings out into individual pots and grow them on in the greenhouse for their first winter. Plant them out into their permanent positions in late spring or early summer, after the last expected frosts.
Cuttings of half-ripe wood, July/August in a frame[].