Longan, Lungan, Dragon's Eye, Cat's Eye
Dimocarpus longan

Family: Sapindaceae

What it is like

Longan, Dimocarpus longan, is a fast-growing, evergreen, well-branched, fruit tree that grows up to 14 m tall with a bole diameter of 1 m. It is native to Southern Asia. Its fruits are highly valued as a food and as a medicine. The fruit has a sweet mucilaginous flesh. It can be eaten raw or dried and preserved in syrup, cooked in sweet and sour dishes or in soups. Medicinally, the fruit is a stomachic, febrifuge and vermifuge, and an antidote for poison. Leaves, flowers, and seeds are also used in traditional medicine. Seeds and rind are burnt for fuel. The wood is used for posts, agricultural implements, furniture, construction, etc.

Dimocarpus longan is an evergreen Tree growing to 12 m (39ft) by 12 m (39ft) at a fast rate. See above for USDA hardiness. It is hardy to UK zone 9. The plant is self-fertile. It is noted for attracting wildlife. Suitable for: light (sandy), medium (loamy) and heavy (clay) soils and prefers well-drained soil. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils. It can grow in semi-shade (light woodland) or no shade. It prefers moist soil.

Height (m): 12

Where it is found

Humid mountain woodlands. Usually found in the understorey of primary forests, sometimes in secondary formations.

E. Asia - China, India, Sri Lanka, Myanmar, Thailand, Cambodia, Laos, Vietnam, Malaysia, Indonesia, Philippines.

Conservation Status: Status: Lower Risk/near threatened

Countries/locations it is found in

Asia, Australia, Brazil, Burma, Cambodia, China*, Cook Islands, East Timor, Hawaii, India, Indochina, Indonesia, Laos, Malaysia, Myanmar, North America, Northeastern India, Pacific, Papua New Guinea, Philippines, SE Asia, Singapore, South America, Sri Lanka, Taiwan, Thailand, Timor-Leste, USA, Vietnam,

How it is used

Food

Rating: 4

Fruit - raw or cooked. The mucilaginous flesh is whitish, translucent and somewhat sweet, though not as flavoursome as the related lychee(Litchi chinensis). It is delicious eaten raw and can also be dried, preserved in syrup, cooked in sweet and sour dishes or in soups. The globose fruits are 12 - 25mm in diameter, with a thin, brittle, yellow-brown to light reddish-brown rind. Longans are much eaten fresh, out-of-hand, but some have maintained that the fruit is improved by cooking. In China, the majority are canned in syrup or dried. For drying, the fruits are first heated to shrink the flesh and facilitate peeling of the rind. Then the seeds are removed and the flesh dried over a slow fire. The dried product is black, leathery and smoky in flavour and is mainly used to prepare an infusion drunk for refreshment.

Medicine

Rating: 3

The flesh of the fruit is administered as a stomachic, febrifuge and vermifuge, and is regarded as an antidote for poison. A decoction of the dried flesh is taken as a tonic and treatment for insomnia and neurasthenic neurosis. In both North and South Vietnam, the 'eye' of the longan seed is pressed against a snakebite in the belief that it will absorb the venom. Leaves and flowers are sold in Chinese herb markets but are not a part of ancient traditional medicine. The leaves contain quercetin and quercitrin. The seeds are administered to counteract heavy sweating and the pulverized kernel, which contains saponin, tannin and fat, serves as a styptic.

Antihydrotic: Reduces perspiration.

Febrifuge: Reduces fevers.

Hypnotic: Induces sleep.

Stomachic: Aids and improves the action of the stomach.

Styptic: An astringent that stops bleeding by contracting the blood vessels.

Tonic: Improves general health. Slower acting than a stimulant, it brings steady improvement.

Vermifuge: Expels and kills internal parasites.

Other

Rating: 2

Small shade tree, Backyard tree, Small flowering tree, Specimen. Other Uses: The seeds, because of their saponin content, are used like soapberries (Sapindus saponaria L.) for shampooing the hair. The seeds and the rind are burnt for fuel. The heartwood is reddish brown it is not clearly demarcated from the lighter-coloured sapwood. The wood is strong, tough, very hard, difficult to split, highly durable, easily but slowly drying with little or no degradation. It is used for posts, agricultural implements, furniture, construction, shuttle pipes, bearings, textile weaving stands and rifle butts. The wood is not highly valued for fuel.

Fuel: Usually wood, plant materials that have been mentioned as being a good fuel.

Furniture: A few miscellaneous uses that do not fit easily into other headings.

Hair: Plants used as hair shampoos, tonics, to treat balding etc.

Pipes: For carrying water etc.

Soap: Plants used directly as a soap substitute.

Wood: A list of the trees and shrubs that are noted for having useful wood.

Food Forest: Plants for Edible Forest Gardens and Food Forests.

How it is grown

Whilst the longan succeeds in warm temperate to tropical areas, it requires a distinct cool season of up to 3 months with virtually no frost to initiate blooming and so does not fruit well at low elevations in the tropics. Flowering is poor after a warm winter and in areas with no clear cool season. It needs chilling temperatures of about 7 - 12°c, or a 2 - 3 month period with temperatures about 15 - 22°c and a short dry period in order to stimulate flowering. From fruit set onwards high temperatures do not hamper development, but nights should not be warmer than 20 - 25°c. The temperature range for growth is reported to be 7 - 36°c with the optimum between 18 - 30°c. Ample soil moisture is needed from fruit set until maturity; suitable annual precipitation is about 1,500 - 2,000mm. The annual rainfall range for growth is reported to be 800 - 3,000mm. Prefers some shade from the strongest sun. Succeeds on most fertile soils so long as there is an abundance of moisture. Prefers a pH in the range 5.5 - 6, but can tolerate 5 - 8. Seedling trees take 7 - 10 years to commence bearing fruit, whilst vegetatively propagated trees can fruit in 3 - 5 years. Full-grown trees given sufficient room may yield 180 - 225 kg of fruit in good years. Larger trees have larger crops but if the trees become too tall harvesting is too difficult, and they should be topped. A serious problem with the longan is its irregular bearing - often one good year is followed by 1 or 2 poor years. There are some named varieties. Trees are usually self-fertile. Flowers mid spring.

Propagating it: Most longan trees are grown from seed. After drying in the shade for 4 days, they should be planted without delay, but no more than 2 cm deep, otherwise they may send up more than one sprout. Germination takes place within 7-10 days. The seedlings are transplanted to shaded nursery rows the following spring and set in the field 2-3 years later during winter dormancy. Air layering. Air-layers bear in 2-3 years after planting. Grafting

Best place to grow:

Habit: Tree

Hardiness: 8-10

Growth: Fast

Soil: Light (sandy), medium, heavy (clay)

Shade: Semi-shade, no shade

Moisture: Moist

Things to keep in mind

Its other names

Local names

Arillus longan, long yan, long yan rou, longan, longan aril, longan arillus, longanbaum, longanier, longyanrou, longán, mata kucing, Mien, Nhan, Lamyai, Laam-yai, Ihau, Loong narn, Mora, Lam-yai, Longyan, Dragon's eye, Lungan, Mata kuching, Ashphal, Wumb, Puvatti, Rongan, Shempuvan, Kanakindeli, Malakcota, Pasakotta, Shempuna, Poripuna, Mulei, Nagalichi, Naga lichu, Tokra, Diengloba, Kelengkeng, Longana, Olho-de-dragao, Long yean gan, Ryugan, Kath lichu, Mirgoch, Tegonog, Marli, Dieng-loba, Bambo, Buku, Dopar, Ihau, Mahau, Rupai, Takuhis, Theifei-mung, oeil de dragon

Synonyms

Euphoria longan (Lour.) Steud. Euphoria longana Lam. Nephelium longana Cambess. Nephelium long-yan B