Please help identify mystery weed/bush/tree/alien!

This plant evidently can grow about 3 feet tall I think, since I've found a few at the fence line. But throughout the lawn there are now small low 6 in bushes, with woody stems. The roots look like a they spread from runners. . . a large central root and then a long lateral root.

Any idea what this could be? I can't find an identification for it on the internet so far.

Thanks!
Joseph

Joseph, try looking up Aspen tree - a type of Poplar.

That's what the leaves look like to me and the tree spreads by runners.