It looks like Oxalis articulata, based on the deeper leaf sinuses imo. Texas has a few other species with similar flower color. Oxalis drummondii, debilis, articulata, brasilensis, and violacea.

I like articulata, because yes, the sinus in these is deep, and it is not deep in brasiliensis. In fact, brasiliensis hardly has any sinus at all! See here a better image of the leaf structure. Good call! Thank you.