Alan:
You've got me curious. I have never heard of (never mind eaten)
either mangosteens or mutingia. Perhaps it's because I live in Germany?
Tell me (us?) more.

Tom:
Muntingia calabura, the strawberry tree. A small tree native to the Amazon
basin but now naturalized in a number of other locations, world-wide.

The fruit is small, shaped like a flat grape, and is red or white.
The flavor is sweet and intense; the flavor kind of explodes in your
mouth. Once when I obtained a small supply of this incredible
fruit, I shared it with a friend. She wrote me a thank you note,
concisely describing the flavor of the fruit as "supernatural".

A good source of info on Muntingia (and also mangosteens) is:

"Fruits of Warm Climates", by Julia F. Morton (1987).
The book is self-published but can be found in most University
libraries, at least in the U.S. This book is virtually an "encyclopedia
of fruit", and I strongly recommend it.

Tom Billings