Helianthus giganteus, is a species of Helianthus native to the eastern United States and eastern and central Canada. Helianthus giganteus is a perennial herbaceous plant growing up to 4 m tall. The leaves are slender, lanceolate.
Helianthus giganteus is a perennial herbaceous plant growing up to 4 m (over 13 feet) tall. The leaves are slender, lanceolate. The flower heads are bright yellow, up to 7 cm (2.8 inches) in diameter. They are most commonly found in valleys with wet meadows or swamps. Giant Sunflower grows from a fleshy root system that develops small rhizomes which allow the plant to spread vegetatively. It prefers full sun, and moist conditions. The genus Helianthus is from two Greek words, helios for 'sun' and anthos for 'flower'. The species giganteus refers to the tall height of the plant. The author name for the plant classification, 'L.' is for Carl Linnaeus (1707-1778), Swedish botanist and the developer of the binomial nomenclature of modern taxonomy. It has invasive tendencies.