ITS–Nephellium rambutan-ake, known as tenggaringin the Indonesian language, is grouped in the same family with the rambutan (Nephellium lappaceum). Like the rambutan, its peel is also covered with thick hairs, but the fruit tastes sour, unlike that of the rambutan.
The plant also has blacker and thinner leaves than the rambutan. Its flowers, yellow in color, come out of the leaf tip. During the flowering season, which lasts from June to August, almost all their leaves produce flowers and fruits. The fruits are initially colored green and turn greenish pink at maturity. The harvest season lasts from October to December.
The sour taste of its fruit causes many people to dislike the plant and cut it down. In fact, the tree has many variants, some of which produce appealing and tasty fruit. Traditionally, the natives have not made selections in cultivating them, so the trees with appealing fruits have not grown popular.
The tree grows in great numbers in farmer’s fields and woods in Central Kalimantan. The locals sell them. They also grow elsewhere in Sumatra and North of Sulawesi but their population is less than in Central Kalimantan.