At last! We've identified the mysterious orange fruit on our tree! We couldn't quite place the taste ... was it a tangerine? But yesterday, in Gelson's, I saw the identical thing on sale. It's a Minneola! Who knew?! These are a cross between a Duncan grapefruit and a Dancy tangerine, and were apparently released in 1931 by the USDA Horticultural Research Station in Orlando. And they give a good crop every other year, which would explain why there were only a few on the tree last year, and why there are many more this (here are a few fallen ones, nestling up to some iron work as though they're forming themselves into the design of a William Morris wallpaper).