Ask Mr. Smarty Plants

You will need to first look at the areas where the trees are blooming, and see if they are in Sun (6 or more hours of sun a day), Part Shade (2 to 6 hours of sun daily) or Shade (less than 2 hours of sun). 

Let us introduce you to an exercise called "Combination Search".  Go to our Native Plant Database  and scroll down to the Combination Search window. Select Texas under Select State, Tree under Habit.  Under Light Requirement, check Part Shade or Shade (whichever applies); under Bloom, check May for when blooms appear and both pink and purple under flower color. Click the "Submit combination Search" button and you will get a list of plants from our NPIN data base with images  that match these characteristics. By clicking on the name of each plant, you will pull up its NPIN page that contains descriptions of the plants along with growth requirements as well as more images. You can generate other lists by changing the choice in the categories.

When we tried this out, without specifying the amount of sun available, we got 19 possibilities. It's always possible, especially in an urbanized area, that the trees you are seeing are escaped non-natives that were in gardens but were planted in wild areas by birds or even the wind. If so, they will not be in our Native Plant Database.  If you can get some pictures of the tree, the bark, the blooms and the leaves, you can submit it to our Plant Identification site with as much description of conditions as you can get. Then, we'll take a crack at figuring out what you have been seeing.