Sunflower seeds are the seeds of sunflowers, large flowering plants which are native to North America. Many people eat sunflower seeds as a snack around the world, and they are reasonably nutritious dietary supplement, as long as they are eaten in moderation and not heavily salted. Sunflower seeds are also used in seed mixtures for birds, and they may appear in bird feeders or feeds for pet avians. Most markets sell sunflower seeds, usually in both shelled and unshelled forms, and they are often used as filler in trail and nut mixes.
The sunflower, or Helianthus annuus, is a distinctive annual plant which produces large bright yellow flowers which resemble small suns. The flowers grow on tall stalks with simple leaves, and they have been known to reach the height of nine feet (three meters) in ideal growing conditions. In fact, the head of a sunflower is composed of a tightly compacted mass of small flowers, each of which matures into a kernel surrounded by a dry husk. Incidentally, sunflowers are often used to demonstrate the appearance of Fibonacci sequences in nature, since the arrangement of seeds exhibits mathematically predictable symmetry.
Native Americans realized the potential of sunflower seeds as a food source several thousand years ago, and they have been growing them ever since. When European explorers first visited the Americas, they brought seeds back with them to attempt cultivating sunflowers on their own. In addition to serving as a food source, sunflower seeds can also be pressed for oil and used for animal fodder for some species. The multi-purpose plants took off in Europe, and were immortalized by Van Gogh, among many others.
Most producers classify sunflower seeds by the color of their husks. The seeds may come in black, striped, or white husks, with striped sunflower seeds being the seeds most commonly eaten. When cracked open, each hull yields a single small kernel which is about the size of a pinky nail. The seeds are creamy white in color, and high in protein and several essential vitamins and minerals. Culinary sunflower seeds have a lower oil content than those cultivated for oil, but they have enough to have a rich flavor.
Many people eat sunflower seeds out of hand, usually shelling them as they eat them. This causes issues of public hygiene in some parts of the world, which is why travelers sometimes see signs exhorting sunflower seed eaters to clean up their messes. In many Mediterranean countries, sunflower seeds are sold fresh and roasted, wrapped up in paper for people to snack on while they attend sports events and celebrations.