Ask Mr. Smarty Plants

At its heart, your question is a legal one and we must recommend seeking legal advice for the issues you raise specifically involving conflicts with your HOA.

All wildflowers are not protected.  The only wildflowers that have legal protection are those listed as endangered species by the state or federal government.  It's not a very long list and chances are slim that any of those species would be found in in your landscape.  We know of no state law in Texas or elsewhere specifically protecting the use of water-conserving plants in landscapes.

Home-owner association agreements have been held by the courts to be very tightly-binding contracts and are considered by some to be more difficult to circumvent or change than city laws and ordinances.  Some home-owners in situations like yours have found at least some relief by negotiating with their HOA boards or even by becoming members of those boards and working within the system.

As Texas experiences more droughts and water-related issues, the public at large, municipalities and HOA's are SLOWLY beginning to understand the advantages of using native (or at least water-conserving) plants.  Education is the key and the lessons are often best taught locally by involved citizens like you.  To that end, local media is sometimes a helpful advocate.

An excellent information resource is the Wild Ones website.  Also, here is an excellent online article on developing local native plant protection ordinances.