Many folks have wondered about these tall purple flowers that grow on the east side of the path that runs along the creek. According to Texas Wildflowers: A Field Guide, they are Mealy Sage, and the plants belong to the mint family. The scientific name is Salvia farinacea.
Everybody knows these—the rain lilies (Cooperia pendunculata). Thanks to the unexpected and very welcome rainfalls we've had lately, we've seen these quite often. They smell so sweet and turn purple before they fade. I've tried with no luck to grow them in my yard. I collected seeds one year, but they never took. They're called wildflowers for a reason, I 'spect.