Purple mangosteen is a tropical fruit which comes from the rainforests of South East Asia. It grows on evergreen trees. It is one of the most popular tropical fruits. It is popular because it has such a sweet, juicy, acidic taste. It has a hard purple shell. Inside the shell, there are white segments, just like an orange. It has to be grown in temperatures of above 40 °F (4 °C). If it is grown in temperatures below that, the plants die.