Thanks for the replies everyone. Clarence you called it the way I remembered it.  I have always called it American Licorice from my FFA range judging days. I have always thought it was a nitrogen fixer too, but the sites I looked up the other day didn't mention it. It does seem to like the very best ground. I guess my memory isn't going.

I am sure that it isn't buckbrush either. This plant gets a cockle bur type seed on it as in picture 1. I think their is a patch of that in this pasture too.