I have no idea what that is at first glance, but I'll be happy to work on it. Can you please send more photos, especially some that have an indicator of the size of the leaves? Also, a photo of the entire plant, and another closeup of the leaves themselves, taken "straight on" instead of from an angle.
We'll give it our best shot! Thanks!
I'm sorry, but those all look nearly identical to me. Can you take some additional pictures since it's in your yard? How large is it? How large are the leaves? It looks like they're all in compound leaves with 5 (?) or 7(?) leaflets per leaf, with them opposite each other except for the last one. Is that correct?
I pulled one up, and it appears to be a potato plant. It had two tubules on the roots.