Planter volunteer ID needed, please.

This plant has come up out of nowhere in a planter a friend of mine has. I've not been able to identify it. I'd appreciate and ID if anyone knows what this plant is. The flowers are very much like wild impatiens as to shape, size and somewhat as far as color.

 

Sesbania?

 

I started with Sesbania and after a few searches I found Sesbania exaltata. That's what it is!

http://www.toledo-bend.us/index.shtml?jun

You'll have to scroll the page a bit. Common name is Dangelpod.

Thanks!

 

That one is also called Sesbania herbacea.