This is a real conundrum. It is a robust shrub, 4 feet tall by 4 feet wide. I have studied Heliopsis and Helianthus images and none of the flowers quite match the ones on this plant, which most closely resemble Gaillardia except that Gaillardia is a ground cover!
I am beginning to think this is a hybrid on account of its often saggitate (triangular) foliage, which means it could not be a Helenium, whose foliage is always lanceolate. Flowers are close to Helenium type but I still see a difference.
Yes after seeing the additional photographs, Helenium and Gaillardia seem to be out of picture, and Heliopsis helianthoides seems to be the logical choice. Although rays are generally narrow in heliopsis helianthoides, but 3-toothed broader rays are frequently seen in some cultivars.
Thanks vngarden and steadycam3
You finally nailed the ID and reminded me that I had already photographed and got identified it in my another forum efloraofindia, photographed from India. I am attaching the same
Verbesina encelioides from Near Panchkula, Haryana, India
Singh, there is only one lonely photo in DG plant files, would you consider posting your lovely shot to the plant files? This goes to you, too, garden18. will you post to plant files? I have some seed photos Im planning to post after seeing there is only one photo there.