Lansium parasiticum "Duku" (Langsat, Lanzones) Seeds
Note: Our farm has been growing Langsat in the middle of Zone 10a since 2015 and our three trees are thriving now in 15 gallon containers and around 5' tall. It is our opinion that Langsat can survive in zone 10a+ with some precautions taken. These seeds are the Duku cultivar which is a common cultivar in Indonesia.
Lansium parasiticum, commonly known as langsat (/ˈlɑːŋsɑːt/), lanzones (/lɑːˈnzɔːnɛs/), or longkong in English; duku in Indonesian or dokong in Malay, is a species of tree in the Mahogany family with commercially cultivated edible fruits. The species is native to Southeast Asia.
The tree is average sized, reaching 30 metres (98 ft) in height and 75 centimetres (30 in) in diameter. Seedling trees 30 years old planted at 8 × 8 meter spacing can have a height of 10 meters and diameter of 25 cm. The trunk grows in an irregular manner, with its buttress roots showing above ground. The tree's bark is a greyish colour, with light and dark spots. Its resin is thick and milk coloured.
The pinnately compound leaves are odd numbered, with thin hair, and 6 to 9 buds at intervals. The buds are long and elliptical, approximately 9 to 21 centimetres (3.5 to 8.3 in) by 5 to 10 centimetres (2.0 to 3.9 in) in size. The upper edge shines, and the leaves themselves have pointed bases and tips. The stems of the buds measure 5 to 12 millimetres (0.20 to 0.47 in).
The flowers are located in inflorescences that grow and hang from large branches or the trunk; the bunches may number up to 5 in one place. They are often branched at their base, measure 10 to 30 centimetres (3.9 to 11.8 in) in size, and have short fur. The flowers are small, with short stems, and have two genders. The sheathe is shaped like a five lobed cup and is coloured a greenish-yellow. The corona is egg-shaped and hard, measuring 2 to 3 millimetres (0.079 to 0.118 in) by 4 to 5 millimetres (0.16 to 0.20 in). There is one stamen, measuring 2 millimetres (0.079 in) in length. The top of the stamen is round. The pistil is short and thick.
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 skin thickness varies with the varieties, from 2 millimetres (0.079 in) to approximately 6 millimetres (0.24 in). With the skin removed, the fruit resembles peeled garlic in appearance, with half a dozen white, translucent lobes, some of which contain a flat, bitter tasting seed. 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. For consumption, cultivars with small or undeveloped seeds and thick aril are preferred.