This is a pea of some sort, probably a Glycine. Without a lot more information, especially a photo of at least two whole leaves showing their shape and relationship to each other is needed. If it is a Glycine, the length of the stalk of the middle leaflet in relation to those of the other two leaflets, and whether it roots at the leaf nodes, is also necessary.
Thanks for teh record Lisa - if you could take a photo with leaves that would be great we don't have a lot of records out your way and would really appreciate some more.