I came across this a few months back and asked my Chinese friends what it might be. None knew. Most suggested it was some kind of immature pumpkin, but I never believed them.
Today, I discovered its Chinese name is 太阳果 (tài yáng guǒ) which translates as "Sun Fruit". Mr. Google has only managed to throw up a suggestion that it may be of S. American origin. It's about 9cm in diameter and 5cm in depth. I'd love to know any European, preferably Latin, name if anyone can help.
By the way, this one has been sitting on my desk in the tropics for about three months, showing no sign of deterioration.
Weird.
Any ideas?