The common sunflower is a large annual forb of the genus Helianthus. It is commonly grown as a crop for its edible oily seeds. Apart from cooking oil production, it is also used as livestock forage, as bird food, in some industrial applications, and as an ornamental in domestic gardens. Wild H. annuus is a widely branched annual plant with many flower heads. The domestic sunflower, however, often possesses only a single large inflorescence atop an unbranched stem.
Helianthus is a genus comprising about 70 species of annual and perennial flowering plants in the daisy family Asteraceae commonly known as sunflowers. Except for three South American species, the species of Helianthus are native to North America and Central America. The best-known species is the common sunflower. This and other species, notably Jerusalem artichoke, are cultivated in temperate regions and some tropical regions, as food crops for humans, cattle, and poultry, and as ornamental plants. The species H. annuus typically grows during the summer and into early fall, with the peak growth season being mid-summer.
Helianthus nuttallii, or Nuttall's sunflower, is a species of sunflower native to northern, central, and western North America, from Newfoundland west to British Columbia, south to Missouri, New Mexico, and California.
Helianthus pauciflorus, called the stiff sunflower, is a North American plant species in the family Asteraceae. It is widespread across the Great Plains, the Rocky Mountains, and the Great Lakes region, and naturalized in scattered locations in the eastern United States and in much of southern Canada.
Helianthus maximiliani is a North American species of sunflower known by the common name Maximilian sunflower.
Helianthus divaricatus, commonly known as the rough sunflower, woodland sunflower, or rough woodland sunflower, is a North American species perennial herb in the family Asteraceae. It is native to central and eastern North America, from Ontario and Quebec in the north, south to Florida and Louisiana and west to Oklahoma and Iowa.
Helianthus grosseserratus, commonly known as sawtooth sunflower or thick-tooth sunflower, is a perennial sunflower in the family Asteraceae, with a large flowering head (inflorescence).
Helianthus schweinitzii is a perennial wildflower endemic to the Piedmont physiographic province of North Carolina and South Carolina. Its common name is Schweinitz's sunflower. It is a member of the sunflower family (Asteraceae). It is one of the rarest species of sunflower in the United States. It is common along utility and highway rights-of-way in North Carolina and South Carolina. There are only about 90 known populations, many containing less than 40 plants each. The U.S. Fish and Wildlife Service listed Schweinitz's sunflower as an endangered species on May 7, 1991.
Helianthus occidentalis, the fewleaf sunflower or western sunflower, is a species of sunflower native to the Eastern and Central United States. It grows mostly in the Great Lakes Region and in the Ozarks, with additional populations scattered as far as Massachusetts, Texas, and the Florida Panhandle.
Helianthus petiolaris is a North American plant species in the family Asteraceae, commonly known as the prairie sunflower or lesser sunflower. Naturalist and botanist Thomas Nuttall was the first to describe the prairie sunflower in 1821. The word petiolaris in Latin means, “having a petiole”. The species originated in Western United States, but has since expanded east. The prairie sunflower is sometimes considered a weed.
Helianthus decapetalus, known by the common names thinleaf sunflower and thin-leaved sunflower, is a perennial forb in the family Asteraceae. It is native to the Eastern and Central United States and Canada, from New Brunswick west to Iowa, Wisconsin, and Ontario, south as far as Georgia and Louisiana. It produces yellow composite flowers in late summer or early fall.
Helianthus deserticola, the desert sunflower, is a plant species native to Arizona, Nevada and Utah. It grows in dry, sun-lit locations at elevations of 400–1,500 m (1,300–4,900 ft).
Helianthus anomalus, the western sunflower, is a species of plants in the family Asteraceae, found in the southwestern United States.
Helianthus eggertii, known as Eggert's sunflower, is a North American species of flowering plants in the family Asteraceae. It is native to Tennessee, Kentucky, South Carolina, and Alabama. It is best known as one of the few plants to have been delisted under the Endangered Species Act because of the species' recovery. It was described by John Kunkel Small in 1903.
Helianthus strumosus, the pale-leaf woodland sunflower, is a species of sunflower native to North America east of the Great Plains and is in the family Asteraceae. It is a native perennial sunflower that resembles other members of this family including the Pale Sunflower, Woodland Sunflower, Hispid Sunflower, and Jerusalem Artichoke. Pale-leaf sunflowers can be found in a diverse range of habitats including woodland areas, prairies, and meadows, providing that these habitats have access to partial sun.
Helianthus neglectus is a species of sunflower known by the common names neglected sunflower. It is native to the southwestern United States in southeastern New Mexico and West Texas.
Helianthus praecox is a North American species of sunflower known by the common name Texas sunflower. It is endemic to Texas. Most of the populations are either along the Gulf Coast or in the Río Grande Valley.
Helianthus smithii is a rare North American species of sunflower known by the common name Smith's sunflower. It is native to the southeastern United States, in Tennessee, Alabama, and Georgia.
Helianthus nuttallii subsp. parishii is a subspecies of the species Helianthus nuttallii in the genus Helianthus, family Asteraceae. It is also known by the common names Los Angeles sunflower and Parish's sunflower. This subspecies has not been seen, in the wild or in cultivation, since 1937.
Charles Bixler Heiser Jr. (1920–2010) was a professor of botany, known as a leading expert on the sunflower genus Helianthus. He is also noteworthy as the author of a "series of popular books that did much to promote botany to the general public."
