Help, what is this...and should I save it.

Michigan, compound leaf, serrated, counted 12 lobes on a stem. Does not smell like rancid peanutbutter when crushed, leaves feel bristley?

This was behind a fence and is growing through a cinderblock...my neighbor did it. Is it worth saving? I am not really looking forward to breaking the block off from around the the trunk without hurting it. Open to ideas how to do that.