Hi Mary,
I am a lurker on this list, but I had to comment on the mesquite beans and pods.  We used to ranch in Live Oak County near George West south of you and the majority of the trees on the ranch were mesquites.  Our cows craved the beans and pods.  They are a legume and full of nutrients.  I made the most delicious jelly from the juice derived from boiling the beans and hulls for 45 minutes.  The taste was similar to honey.  That was back in my "sugar eating" days.  I wonder if you boiled them and cooked them down significantly would they render a sweet juice?

Jan in Colorado