Lansium parasiticum, also known as langsat or lanzones, is a species of tree in the Mahogany family. The plant, which originates from western Southeast Asia, bears edible fruit. It is the provincial flower for the Indonesian province of South Sumatra.
The fruit can be elliptical, ovoid or round, measuring 2 to 7 centimetres (0.79 to 2.76 in) by 1.5 to 5 centimetres (0.59 to 1.97 in) in size.
Fruits look much like small potatoes and are borne in clusters similar to grapes. The larger fruits are on the variety known as duku. It is covered by thin, yellow hair giving a slightly fuzzy aspect.
The fruit contains 1 to 3 seeds, flat, and bitter tasting; the seeds are covered with a thick, clear-white aril that tastes sweet and sour.The taste has been likened to a combination of grape and grapefruit and is considered excellent by most. The sweet juicy flesh contains sucrose, fructose, and glucose. Longkong Fruit plants in Kerala is also available now..