Longan 龍眼

Lengkeng, sold in Indonesia, Moh. Sabain,Malang, P.R. Mod, Malang

龍眼，又稱桂圓、福圓，壽命最長可達400多年。龍眼為栽培果樹，與荔枝、香蕉、鳳梨同為華南四大珍果。越南、印尼等地亦有生產。可用作風景林和防護林，木材堅固耐久，根、干可以提烤膠。疏林砍伐，根幹經悶燒製成木炭，熱值高，味道佳，是碳烤使用者的首選。其花蜜稱為「龍眼蜜」，是蜂蜜中品質極好者，色澤金黃透亮。

果實可生吃，也可以含殼烘烤成果乾稱為龍眼乾，一者可以常年存放，也是藥用的最佳選擇；二者避免產季生果產量過多，價格不好或滯銷，造成果賤傷農。還可與銀耳等熬成甜湯，十分滋潤。龍眼乾含殼保存，去殼去子核後可以保存更久，利於長年食用或藥用，而對於風乾的果實肉，人們多以「桂圓」稱之。

Dimocarpus longan, commonly known as the longan, is a tropical tree that produces edible fruit. It is one of the better-known tropical members of the soapberry family (Sapindaceae), to which the lychee also belongs. Included in the soapberry family are the lychee, rambutan, guarana, korlan, pitomba, Genip and ackee. Longan is commonly associated with lychee, which is similar in structure but more aromatic in taste. It is native to Southern Asia.

The fruit is sweet, juicy and succulent in superior agricultural varieties. The seed and the shell are not consumed. Apart from being eaten fresh and raw, longan fruit is also often used in Asian soups, snacks, desserts, and sweet-and-sour foods, either fresh or dried, and sometimes preserved and canned in syrup. The taste is different from lychees; while longan have a drier sweetness, lychees are often messily juicy with a more tropical, sour sweetness.

Dried longan are often used in Chinese cuisine and Chinese sweet dessert soups. In Chinese food therapy and herbal medicine, it is believed to have an effect on relaxation. In contrast with the fresh fruit, which is juicy and white, the flesh of dried longans is dark brown to almost black.