Hovenia dulcis, the oriental raisin tree, is a hardy tree found from Asia, over Eastern China (万寿果) and Korea to the Himalayas (up to altitudes of 2,000 m), growing preferably in a sunny position on moist sandy or loamy soils. The tree has been introduced as an ornamental tree to several countries, and the fruit is also edible.

Description

Tree, rarely a shrub, deciduous, to 10–30 m tall. Branchlets brown or black-purple, glabrous, with inconspicuous lenticels. The glossy leaves are large and pointed. The trees bear clusters of small cream-coloured hermaphroditic flowers in July. The drupes appear at the ends of edible fleshy fruit stalks (rachis), which is a type of accessory fruit.

Uses

The fleshy rachis of the infructescence is sweet, fragrant and is edible raw or cooked. Dried, they look and taste like raisins. An extract of the seeds, bough and young leaves can be used as a substitute for honey^[1] and is used for making wine and candy.

An extract of the leave contains hodulcine, a glycoside which exhibits an anti-sweet activity.^[2] Ampelopsin is a flavanonol found in H. dulcis and is credited with hepatoprotective effects.^[3]

The timber is fine and hard and is used for building construction and fine furniture.

Health products

The Korea Food & Drug Administration approved in December 2008 that extracts of the Hovenia dulcis (헛개나무) fruit can protect and help recover the liver from substances such as alcohol. The main chemical for this effect in Hovenia dulcis is Quercetin, which has anti-inflammatory and anti-oxidant properties.

There is a commercially available dairy product in Korea called Kupffers offers 2,460 mg of Hovenia dulcis extract.

Dihydromyricetin can be isolated from Hovenia dulcis and is under study as an alcohol antagonist and as a treatment for alcoholism.^[4]

Reforestation

In Thailand Hovenia dulcis is relatively rare, typically found in the stream-irrigated valleys of primary lower mountain evergreen forest located between 1,075 and 1,250 metres above sea level. However, it is one of 30 potential species identified as a substitute for Eucalyptus spp., commonly planted for reforestation, that would meet the demand for rapid growth while not disturbing the ecological balance.^[5][6]

In Thailand Hovenia dulcis grows at roughly the same rate as eucalyptus, reaching six metres in height within three years.^[5] One major asset is that the growth form of the tree allows other species to regenerate nearby. As well, the tree attracts several varieties of both birds and mammals which feed on the seeds and fruit.^[7] As well as promoting fauna diversity, this process assists in improving soil fertility through humification.^[5]

Synonyms

• Hovenia acerba - Lindl.
• Hovenia inequalis - DC.

References

Further reading

• Anthony Julian Huxley; Mark Griffiths, Royal Horticultural Society (Great Britain) (1992-04-01). Dictionary of Gardening. ISBN 978-0-333-47494-5. 
• Macoboy, Stirling (1986). What Tree is That?. ISBN 978-1-86302-131-9. 
• Fang, Hsun-Lang; Lin, Hui-Yi; Chan, Ming-Che; Lin, Wei-Li and Lin, Wen-Chuan. "Treatment of chronic liver injuries in mice by oral administration of ethanolic extract of the fruit of Hovenia dulcis. American Journal of Chinese Medicine 35.4 (2007): 693-703.
• Koller, G.L. and Alexander, J.H. "The raisin tree: Its use, hardiness and size."Arnoldia 39.1 (Jan/Feb 1979): 6-15.