Sunflower, the common name for a genus of annual or perennial plants. About half of the 100 or so species in the genus are native to North America.
The sunflower is a leafy plant with a hairy stem. At the top of the stem is a large, round flower head consisting of a central brownishmaroon disk surrounded by bright yellow ray flowers. The leaves are heart-shaped with toothed edges. The sunflower blooms in late summer or early fall. The flower head is heliotropicthat is, it follows the movement of the sun from east to west during the day. Sunflowers grow wild in dry woods. Some, such as the showy sunflower and the dark-eye sunflower, are grown as ornamentals. Others, particularly the common sunflower, or mirasol, are cultivated mainly for their oil and seeds. The Jerusalem artichoke is a sunflower grown for its edible underground tubers.The sunflower is a tall, leafy plant with a hairy stem and a large, round flower head.
The common sunflower grows up to 13 feet (4 m) high and has leaves one foot (30 cm) long. Whole seeds from the plant are used as bird and poultry feed. They are also roasted and eaten like peanuts. Some of the seeds are crushed to remove the oil, which is processed and bottled as vegetable oil or is used in margarine, salad dressings, and mayonnaise. It is also used in paints and varnishes and in the manufacture of plastics. Hulls from the crushed seeds are processed to yield pectin, a thickening agent used in preserves.
The showy sunflower is Helianthus laetiflorus; dark-eye, H. atrorubens; common, H. annuus. Sunflowers belong to the composite family, Compositae.