Source: Magness et al. 1971
Sunflower is native to the western U.S., but principal commercial production of the seed for oil is in other countries, especially Russia. World production of oil averaged near 2,670,000 tons from 1964 to 1966, but sunflower oil production in the U.S. is very limited. The plant is a large, rough annual, with a stiff stem up to 10 or 12 feet tall. Leaves are cordate to ovate, rough, up to 12 inches long.
The angular seeds are up to 0.25 inch long, and are densely packed in the flat, terminal heads, which may be more than a foot across. Seeds are exposed in the head during growth. Seeds normally contain about 25 percent of the semi-drying oil, but this has been increased by breeding to above 40 percent in selections in Russia. Oil is usually expressed by an initial cold press, followed by hot pressing. The cold-press oil is used as a salad and cooking oil and for margarine, the hot-press mainly in industry. The press cake is a very valuable animal feed. Seeds are also consumed as nuts.