Can you help identify this plant? We are in Hockley, Texas and this stuff is taking over!

I'm pretty sure it's prickly sida (Sida spinosa). It's about the toughest stem of any plant I know of, except perhaps the Western starthistle. Goats will eat it, and I've often wondered whether it could be retted in water and a usable fiber made of it.....

I know the deer LOVE it in the winter.