Mangosteen (Garcinia mangostana), also known as the purple mangosteen, is a tropical evergreen tree with edible fruit native to island nations of Southeast Asia. Its center of origin is peninsular Malaysia, although a precise origin is uncertain due to widespread prehistoric cultivation. It grows mainly in Southeast Asia, southwest India and other tropical areas such as Colombia, Puerto Rico and Florida, where the tree has been introduced. The tree grows from 6 to 25 m (19.7 to 82.0 ft) tall. The fruit of the mangosteen is sweet and tangy, juicy, somewhat fibrous, with fluid-filled vesicles (like the flesh of citrus fruits), with an inedible, deep reddish-purple colored rind (exocarp) when ripe. In each fruit, the fragrant edible flesh that surrounds each seed is botanically endocarp, i.e., the inner layer of the ovary. Seeds are almond-shaped and -sized.
In South-East Asia, mangosteen is commonly known as the "Queen of Fruit", and is frequently paired with durian, the "King of Fruit". In Chinese food therapy, mangosteen is considered "cooling", making it a good counterbalance to the "heaty" durian.
Before ripening, the mangosteen shell is fibrous and firm, but becomes soft and easy to pry open when the fruit ripens. To open a mangosteen, the shell can be scored with a knife, pried gently along the score with the thumbs until it cracks, and then pulled apart to reveal the fruit. Alternatively, the mangosteen can be opened without a knife by squeezing the shell from the bottom until it breaks, allowing the shell to be removed and the fruit eaten while intact with the stem. Occasionally, during peeling of ripe fruits, the purple exocarp juice may stain skin or fabric. In Vietnam, the ripe fruit is also used as a salad ingredient.