Helianthus angustifolius, commonly called Swamp Sunflower or Narrowleaf Sunflower, is a perennial sunflower native to moist areas of the central and eastern United States. Swamp Sunflower grows up to five feet tall and spreads slowly through rhizomes. Many yellow flowers bloom in the fall. Bees and butterflies visit the flowers, and birds enjoy the seeds throughout winter. Swamp sunflower provides a dramatic accent to borders or naturalized plantings. Plant with native grasses and other moisture-loving plants, such as cardinal flower.