The mangosteen (Garcinia mangostana) is a tropical evergreen tree, believed to be from the Sunda Islands and the Moluccas. The tree grows from 7 to 25 meters tall. The edible fruits are purple or reddish purple when ripe. The mangosteen fruit is know as the "queen of fruits," while the durian (Durio zibethinus) is know as the "king of fruits."
The outer shell of the fruit is rather hard, typically 4-6 cm in diameter, resembling a spherical, black bomb that one might find in a cartoon or video game. Cutting through the rather daunting shell, one finds a very pale, fleshy fruit 3-5 cm in diameter. Depending on the size and ripeness, there may or may not be pits in the segments of the fruit.
Their taste may be compared to an underripe strawberry with hints of sweet orange, but comparison doesn't do it justice. Buy one in Chinatown and find out for yourself.
See also: list of fruits