Helianthus angustifolius

About

Helianthus angustifolius is a species of sunflower known by the common name narrowleaf sunflower or swamp sunflower. It is native to the south-central and eastern United States, found in all the coastal states from Texas to Long Island, and inland as far as Missouri. It is typically found in the coastal plain habitat, particularly in wet areas. Although, in general, this species prefers low, moist ground, it is tolerant of conditions varying from bogs and swamps near sea level to relatively dry, well drained, gravelly clay. It is not particularly drought resistant.

Summary from Wikipedia