I'm going with poplar also. The white streaks in the fissures of the bark and light color with green center and easy splitting and loses a lot of weight. I have a cord or 2 in the stacks and it makes great heat, just doesn't last like the better hard woods. Burn it on the weekends or use it to burn the coals down
I agree it could be Poplar. Kind of looks like Tree of Heaven as well. If it had a foul odor and thick twigs probably Tree of Heaven. Very fast grower as well.