IM-1 is an imbe, a rare fruit in the Garcinia genus. Ours was obtained in 2013, from Treehouse, at one of the last tree sales before the closing of this well-known Pine Island nursery. A slow grower, it first fruited in 2017. The first fruits were one the tart side of this variable fruit, and time will tell whether it produces sweeter fruits.
Although imbe is generally dioecious (some trees are male and others female), IM-1 is a hermaphroditic specimen, producing both male and female flowers and able to self-pollinate. In this photo, the flowers on the left are male, and the one on the right is female.