Found this growing in what should be native prairie. Doesn't appear to be viney.
looks like a walnut maybe?
Perhaps a Vicia based on that flower bud.
Here is a shot showing the flowers.
What size is that flower head and leaves? I'd say Vicia too. It's so chewed up it's hard to see details but Vicia cracca is a very widespread one with similar features and colouring.
It also reminds me of Tephrosia, although I can't say the flowers are right ....
The individual flowers are about finger nail size. The plant about 1 foot tall.
Finger nail size is too big for V cracca, unless it is a very dainty pinky.
How about Lathyrus japonicus?
Here is a link that might be useful: page with pictures
An interesting id. The plant was found on RR right away on high dry ground among mostly Poison Ivy. Web pictures seem to show similar flowers. But Minnesota Wildflowers site also references Lathyrus venosus which seems to be more widespread in this area.
Here is a link that might be useful: Veiny Pea