What about Baptisia Tinctoria? Commonly know as wild indigo (horseflyweed, yellow false indigo)? The leaves really look like it.
I have a book called "Wildflowers of the Shenandoah Valley and Blue Ridge Mountains". When I was looking up m sister's wildflowers, I came across this one and that is why yours looked so familiar.
Wikipedia reference: [url=thttp://en.wikipedia.org/wiki/Baptisia_tinctoria]thttp://en.wikipedia.org/wiki/...[/url]
