This was the best photo I could get. For scale flowers are 5 mm. It’s currently on a fulls sun, drier site with clay soils. I thought it was Houstonia but not sure.
you are correct – it is a Houstonia. Nice picture! I would call it Houstonia pusilla, a common annual in disturbed areas in the early spring. There are two other, less likely, possibilities: Houstonia micrantha and Houstonia rosea. I would say the flowers are too large to be H. micrantha. Also, the flower color for those latter two species is mostly white to pale pink. The calyx lobes seem a bit long for H. pusilla – but that may be variable.
Steve Hill SCNPS