I've lived in this area all of my life, grew up on a farm and ran around the woods all of the time as a kid. Thought I new all of the trees that grew around here. I have been seeing more and more of these trees. Could someone identify it for me. It spreads by its roots, underground, forming dense clumps. Very hard to kill, although the saplings are susceptible to a heavy dose of 4-6 % roundup. Any help would be appreciated.