Rambutan

The rambutan is a medium-sized evergreen tree native to Southeast Asia. It belongs to the Sapindaceae family and is famous for its edible fruit. The name comes from the Malay word for "hair." This refers to the fleshy, pliable spines that cover the fruit's skin. These spines are technically called spinterns. They play a role in transpiration, which is how the fruit manages water.

The tree typically grows to a height between 15 and 25 meters. It thrives in warm, humid tropical climates. These trees prefer temperatures around 25 degrees Celsius. They are sensitive to any temperatures falling below 10 degrees Celsius.

Understanding how the rambutan produces fruit requires looking at its flowers. The flowers are small, aromatic, and lack petals. These flowers grow in clusters called panicles. There are three different types of rambutan trees based on their flowers. Male trees produce only staminate flowers, which means they produce no fruit. Female trees produce flowers that are only functionally female. Most commercial trees are hermaphroditic. This means they produce flowers that are female but also contain a small percentage of male flowers.

This variety is helpful because it allows for more efficient fruit production.

Pollination is a vital step in the life cycle of the rambutan. Because many female flowers lack anthers, the tree relies on insects for cross-pollination. Bees are the most important pollinators for this species. Specifically, honey bees like *Apis dorsa* and *A. cerana* are major visitors. Flies and ants also act as pollinators. In Thailand, *A. cerana* is the preferred species for small-scale pollination. As bees forage for nectar, they contact the stigma of female flowers. They also gather sticky pollen from male blossoms. This process moves the pollen needed to create fruit.

The fruit itself is a single-seeded drupe. It can be round or oval in shape. The fruit grows in loose, pendant clusters containing ten to twenty fruits. The skin is usually reddish, though it can sometimes be orange or yellow. Inside the skin is the aril, which is the edible flesh. The aril is translucent and can be white or pale pink. It has a sweet, mildly acidic flavor similar to grapes. Inside the aril sits a single, glossy brown seed.

While the seed can be eaten, it is bitter and has narcotic properties.

Humans have moved the rambutan across the globe over many centuries. Between the 13th and 15th centuries, Arab traders introduced the fruit to Zanzibar and Pemba in East Africa. In the 19th century, the Dutch moved rambutans from Indonesia to Suriname in South America. This helped the plants spread to the tropical Americas, including Colombia, Ecuador, and Cuba. The fruit reached the Philippines in 1912. In 1906, there was an attempt to grow rambutans in the Southeastern United States. Most of those attempts failed, except in Puerto Rico.

There is incredible variety among rambutan plants, with over 200 known cultivars. Many of these are selected for compact growth to make harvesting easier. In Indonesia, researchers identified 22 high-quality cultivars. Five of these are leading commercial varieties, such as 'Binjai' and 'Rapiah.' In the Philippines, the 'Maharlika Rambutan' is highly valued. While it tastes the same as other types, it is popular because the fruit separates cleanly from the seed. This is known as a "freestone" characteristic.

This makes the fruit much easier to prepare for eating.

Cultivating rambutan requires specific environmental conditions. The trees grow best in deep, well-drained soil like clay loam or sandy loam. They are often planted on hilly terrain. Farmers can grow them through grafting, budding, or air-layering. A budded tree might produce fruit in just two to three years. However, the best production usually happens after eight to ten years. Thailand is currently the world's largest producer. It produces about 450,000 tonnes of fruit. Indonesia follows with 100,000 tonnes, and Malaysia produces 60,000 tonnes.