Helianthus smithii is a rare North American species of sunflower known by the common name Smith's sunflower. It is native to the southeastern United States, in Tennessee, Alabama, and Georgia. Helianthus smithii grows in wet, mucky soils in marshes, ditches, and roadsides. It is a perennial herb up to 260 cm (over 8 feet) tall, spreading by means of underground rhizomes. One plant usually produces 1-15 flower heads, each containing 12–23 yellow ray florets surrounding 100 or more red, yellow, or brown disc florets.