Yes Yedidyah that is a mulberry tree.

Yes Tony, like Lisa said, those are hard to identify. You will have to wait for the fruit, and then when you cut into it. The color of the flesh, plus the size of the fruit should be a help. My cactus is blooming too for the first time this month, not fruit set yet. I keep hoping. I have the physical graffity, and yellow variety, if you are interested in cutting. Veronika

Look here: http://www.mango.org/mango-varieties-and-availability

It's a cherry - my guess is... either P. serotina (wild black cherry) or P. pensylvanica (pincherry)... leaning toward pincherry due to the red color.