I have this identified as P. incarnata on the photograph, which I thought it was when photographed; after checking more closely, it is more likely a cultivar of P. caerulea. The latter is a native of South America but grown worldwide as a garden plant.
P. incarnata is native to the southern United States. A perennial trailing vine, it’s found growing in thickets, disturbed areas, near riverbanks and roadsides.
This subject is growing at Phipps Conservatory & Botanical Gardens, Pittsburgh, PA.