Description

General aspect and origins - Euphoria longan is sometimes named Nephelium longan or Dimocarpus longan. It is also commonly known as longan, lungan or dragon's eye. This is a tree that can reach up to 60 ft (20 m) tall, and that is native to Southeastern China, (Guangdong, Guangxi, the Hainan Area and Yunnan) to Southwestern India and to Sri Lanka.
Leaves - The longan has an evergreen foliage. Leaves are alternate, compound and glossy. Young leaflets are red-green, and turn dark-green with age.
Flowers - The inflorescence of this tree is made of small pale-yellow to yellow-brown flowers, that are borne in terminal panicles that can be up to 16 in (40 cm) long.
Fruits - The longan is a globose fruit that is about .75 - 1 in (2 - 2.5 cm) in diameter. It has a thin and brittle rind, which is brown-red to brown yellow. The rind is covered with regular protuberances, somewhat similar to that of the litchi, but smaller. The flesh is translucent and sweet, and contains a single dark-brown seed.

The longan is generally eaten fresh. It can also be canned, just like litchees or rambutans. It can also be used as an ingredient for drinks and liqueurs.

There are several longan varieties and cultivars, with for instance:

• 'Biew Kiew' - from Thailand, rather productive, relatively late, with good quality fruits.


• 'Diamond River' - also native to Thailand, good fruits of medium size, relatively early. named 'Phetsakon' in Thailand.


• 'Fukien Lungan' - from China, and mainly grown in Taiwan.


• 'Kohala' - Selected in Hawaii, and grown in Hawaii and in Florida. Good fruits of medium size.


• 'Shixia' - A Chinese selection that is moderately vigorous, and that can be heavily pruned.


• 'Sri Chompoo' - from Thailand. Large fruits of good quality.


• 'Wu Yuan' - sour and small fruits, which are mainly used for canning.

Culture

The longan is a tree that can grow in tropical and some subtropical areas.(with humid summers and dry winters) However, fully established trees have been reported to withstand cold temperatures down to about 24°F (-4°C). Young trees will be heavily damaged below 28°F (-2°C).
Soil - In commercial orchards, longans are generally grown with an average density of about 100 to 500 trees per ha. However, some orchards with dwarfed varieties can contain up to 1500 trees per ha.

Longans can grow in a relatively large range of soils, but a fertile ground will be prefered for good crops. This tree can withstand occasional droughts.

Propagation

Longan can be propagated from seeds, cuttings, air-layering, and grafting. Generally, seedlings are not true to type. Moreover, it can take up to 8 years from the seed to obtain the first crop.

If sown, seeds should be as fresh as possible. In good conditions, seeds sprout very quickly (1 - 2 weeks)