When I first saw this flower at a distance in Descanso Gardens in La Canada Flintridge California, I thought it was a sunflower, but it turned out to be a Jerusalem artichoke.
The tubers of this plant were prized by Edgar Casey for their health benefits. Something they have in common with leeks is that they are rich in the Prebiotic Inulin, which is vital for good digestion.
Another name for this beautiful and nutritious plant is sunchoke, and yes they are related to sunflowers.