The sunflower is an annual plant grown as a crop for its edible oil and edible fruits (commonly called "sunflower seeds"). Sunflower is also used as bird food, as livestock forage (as a meal or a silage plant) and in some industrial applications. The plant was first domesticated in the Americas. Wild Helianthus annuus is a widely branched annual plant with many flower heads. The domestic sunflower, however, possesses a single large inflorescence (flower head) atop an unbranched stem. The name sunflower derives from the flower head's shape, which resembles the Sun.
Sunflower seeds were brought to Europe from the Americas in the 16th century, where, along with sunflower oil, they became a widespread cooking ingredient. Source