Ruellias in Central Texas copied from @arnanthescout
https://www.inaturalist.org/posts/70116-ruellias-in-central-texas
About the Ruellias
Ruellias are sometimes called Wild Petunias, but they aren't Petunias so that's a LIE! They're named after Jean Ruelle, who was a French botanist and physician during the Renaissance Period. There are lots of plants named after botanists.
Most, if not all, will have the flowers that open for only one day—they open in the morning and fall off by the evening.