Found by the marsh in charleston at the edge of the forest. Beans.
Hi Alexandra,
This is Sesbania vesicaria, Bagpod. It is rather common in disturbed wetlands. Parts of it are poisonous if eaten. You can see more about it here: http://davesgarden.com/guides/pf/go/107662/
Sincerely,
Steve Hill, Botanist, SCNPS