Helianthus angustifolius / Swamp sunflower

As the name suggests, Swamp Sunflower produces bright yellow flowers in fall and thrives in sunny, wet habitats. The leaves are a host plant for butterflies and the flowers are an important nectar source for pollinators. This tough plant is also salt tolerant. Grows up to 8 feet tall.

For more information see below:

https://www.wildflower.org/plants/result.php?id_plant=hean2