A closeup of one sunflower, with bright red-orange petals with yellow tips.
The sunflower is a familiar plant that has the distinction of being the only widely used crop species that originated in North America. Although Native Americans domesticated the plant and selected for plants with single heads and larger seeds, its initial use after being introduced into Europe was primarily as an ornamental plant in gardens. It became popular as a crop plant first in Russia, largely as a consequence of edicts from the Eastern Orthodox Church concerning diet restrictions during Lent. During Lent, consumption of oils from a variety of plants (e.g. olive, palm, sesame) was forbidden, but sunflower, a recent arrival, was not banned and sunflower became an important crop in Russia by being a source of oil during Lent. It is now the national flower of both Russia and the Ukraine. Early in the 20th century sunflower came back to North America as a crop grown primarily for its oil in both the northern U.S. and in Canada. In the southern hemisphere, Argentina is a major producer of sunflower. The oil from sunflower is used both in cooking and also industrially (e.g. as a base for paints). It can be used as a substitute for diesel oil directly or after first being converted to biodiesel. After oil has been extracted the remaining seed can be used for animal feed. To a limited extent sunflower seeds are eaten directly, especially by baseball players!
Phylogeny
Helianthus is a genus in the sunflower family (Asteraceae), one of the largest families angiosperms. There are roughly 70 species, both annual and perennial, with H. annuus (an annual) being the most important crop species. A perennial species (H. tuberosus), called Jerusalem artichoke, is occasionally grown for its edible tubers.
Structure