This is cat's claw blooming on my back fence and
on the little half wall on the driveway.
This plant is very aggressive and has a 3 pronged claw that enable it to climb most anywhere. These blooms turn into 12-18 inch pods that are not so attractive.
Cats Claw is a vine commonly known as Una de Gato and is used traditionally in Peruvian medicine for the treatment of a wide range of health problems, particularly digestive complaints and arthritis and to treat wounds, stomach problems, cancer, and more but not used here in the U.S. that I know of.