Sunflower, plant of the genus Helianthus of the family Asteraceae, native primarily to North and South America. The common sunflower is an annual herb with a rough hairy stem 1–4.5 metres (3–15 feet) high, broad, coarsely toothed, rough leaves 7.5–30 cm (3–12 inches) long, and heads of flowers 7.5–15 cm wide in wild specimens and often 30 cm or more in cultivated types. The disk flowers are brown, yellow, or purple; the ray flowers are yellow. The oval hairy leaves are arranged in spirals. The sunflower plant is valuable from an economic as well as from an ornamental point of view. The leaves are used as fodder, the flowers yield a yellow dye, and the seeds contain oil and are used for food. The yellow, sweet oil obtained by compression of the seeds is considered equal to olive or almond oil for table use. Sunflower oil cake is used for stock and poultry feeding. The oil is also used in soap and paints and as a lubricant. The seeds may be eaten dried or roasted. Argentina, Russia, Ukraine, France, the United States, and China are the leading producers of sunflower seed.
Of the approximately 50 species of Helianthus, only a few are cultivated, some for their spectacular size. They are tall, hardy annual or perennial herbs, several of which can be grown in gardens with moderately good soil.