I gave up trying to ID trees by pictures a long time ago. In most cases you gotta use all your senses to do a proper ID. Thank God you can't smell things from the internet (at least not yet).
Hard to tell from the picture, but it is either a black gum or a serviceberry. [STRIKE]The bark color is making me lean more toward the serviceberry.[/STRIKE] On second look at the pic, I believe Mike has it with Black Gum.
Whatever it is (Black Gum) it has a big nasty knot that healed up... If your thinking about making lumber out of that section of the trunk. You do realize that big nasty knot will run right down to the heartwood and will be in every board that is sawn from that quarter face of the log.
Yup, not cutting it yet. Its in a 1/4acre part of my yard that is a small pine stand. And I will clean it up one of these days. If anything I would cut it up for turning, got to love the black hole that is woodturning