Coral vine (Antigonon leptopus) is native to Mexico, but I can attest that it grows well in the San Antonio, Texas, area.
Maybe someone else planted it long ago, but my family has lived in this house for 30 years, and we have neither planted it nor tended it. It freezes back every winter and comes back every summer with a lush display of pink flowers interspersed with a few white ones. Monsoon or drought, it always comes back.
I gather some specimens have more white flowers. However it got into my yard, I am very glad it is there.
The photos show it growing over Japanese Ligustrum. The vine has done the Ligustrum no harm.