Guesses, anyone?

This is another in the pea family, like yesterday's vetch, but the only obvious similarity is in the foliage. I think the flowers are stunningly beautiful - pink and yellow - and when I first came across it I thought it must be something very exotic, but once I figured out what it was I saw it everywhere along the sandy roadsides of the Pine Barrens. The only hint I'll give you is that the plant contains the chemical rotenone and is thought to have been used by American Indians to stun fish, among other things. I'm not exactly sure how fish are stunned using a plant, but it's fun to imagine how that might be accomplished.