''Helianthus'' () is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial n ...

comprising about 70

species In biology, a species is the basic unit of Taxonomy (biology), classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of ...

of annual and perennial

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. They include all forbs (flowering plants without a woody stem), grasses and grass-like plants, a vast majority of ...

s in the daisy family

Asteraceae The family Asteraceae, alternatively Compositae, consists of over 32,000 known species of flowering plants in over 1,900 genera within the order Asterales. Commonly referred to as the aster, daisy, composite, or sunflower family, Compositae ...

commonly known as sunflowers. Except for three

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the souther ...

n species, the species of ''Helianthus'' are native to North America and

Central America Central America ( es, América Central or ) is a subregion of the Americas. Its boundaries are defined as bordering the United States to the north, Colombia to the south, the Caribbean Sea to the east, and the Pacific Ocean to the west. ...

. The best-known species is the common sunflower (''Helianthus annuus''), whose round flower heads in combination with the ligules look like the Sun. This and other species, notably

Jerusalem artichoke The Jerusalem artichoke (''Helianthus tuberosus''), also called sunroot, sunchoke, wild sunflower, topinambur, or earth apple, is a species of sunflower native to central North America. It is cultivated widely across the temperate zone for it ...

(''H. tuberosus''), are cultivated in

temperate In geography, the temperate climates of Earth occur in the middle latitudes (23.5° to 66.5° N/S of Equator), which span between the tropics and the polar regions of Earth. These zones generally have wider temperature ranges throughout t ...

regions and some

tropical The tropics are the regions of Earth surrounding the Equator. They are defined in latitude by the Tropic of Cancer in the Northern Hemisphere at N and the Tropic of Capricorn in the Southern Hemisphere at S. The tropics are also referred to ...

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. Several

perennial A perennial plant or simply perennial is a plant that lives more than two years. The term ('' per-'' + '' -ennial'', "through the years") is often used to differentiate a plant from shorter-lived annuals and biennials. The term is also wide ...

''Helianthus'' species are grown in gardens, but have a tendency to spread rapidly and can become aggressive. On the other hand, the whorled sunflower, ''Helianthus verticillatus'', was listed as an

endangered An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching and inv ...

species in 2014 when the U.S. Fish and Wildlife Service issued a final rule protecting it under the Endangered Species Act. The primary threats are industrial forestry and

pine A pine is any conifer tree or shrub in the genus ''Pinus'' () of the family (biology), family Pinaceae. ''Pinus'' is the sole genus in the subfamily Pinoideae. The World Flora Online created by the Royal Botanic Gardens, Kew and Missouri Botanic ...

plantations in Alabama, Georgia, and Tennessee. They grow to and are primarily found in woodlands, adjacent to creeks and moist, prairie-like areas. The common sunflower is the national flower of

Ukraine Ukraine ( uk, Україна, Ukraïna, ) is a country in Eastern Europe. It is the second-largest European country after Russia, which it borders to the east and northeast. Ukraine covers approximately . Prior to the ongoing Russian invas ...

, cultivated there for several centuries.

Description

Sunflowers are usually tall annual or perennial plants that in some species can grow to a height of or more. Each "flower" is actually a disc made up of tiny flowers, to form a larger false flower to better attract pollinators. The plants bear one or more wide, terminal capitula (flower heads made up of many tiny flowers), with bright yellow ray florets (mini flowers inside a flower head) at the outside and yellow or maroon (also known as a brown/red) disc florets inside. Several ornamental

cultivars A cultivar is a type of cultivated plant that people have selected for desired traits and when propagated retain those traits. Methods used to propagate cultivars include: division, root and stem cuttings, offsets, grafting, tissue culture ...

of '' H. annuus'' have red-colored ray florets; all of them stem from a single original mutant. While the majority of sunflowers are yellow, there are branching varieties in other colours including, orange, red and purple. The

petiolate Petiole may refer to: *Petiole (botany), the stalk of a leaf, attaching the blade to the stem *Petiole (insect anatomy) In entomology, petiole is the technical term for the narrow waist of some hymenopteran insects, especially ants, bees, a ...

leaves are dentate and often sticky. The lower leaves are opposite, ovate, or often heart-shaped. The rough and hairy stem is branched in the upper part in wild plants, but is usually unbranched in domesticated cultivars. This genus is distinguished technically by the fact that the ray florets (when present) are sterile, and by the presence on the disk flowers of a pappus that is of two awn-like scales that are caducous (that is, easily detached and falling at maturity). Some species also have additional shorter scales in the pappus, and one species lacks a pappus entirely. Another technical feature that distinguishes the genus more reliably, but requires a microscope to see, is the presence of a prominent, multicellular appendage at the apex of the style. Further, the florets of a sunflower are arranged in a natural

spiral In mathematics, a spiral is a curve which emanates from a point, moving farther away as it revolves around the point. Helices Two major definitions of "spiral" in the American Heritage Dictionary are:H. radula'', lacks ray flowers altogether. Overall, the macroevolution of the ''Helianthus'' is driven by multiple biotic and abiotic factors and influences various floral morphology. ''Helianthus'' species are used as food plants by the

larva A larva (; plural larvae ) is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle. Th ...

e of many lepidopterans.

Growth stages

The growth of a sunflower depends strictly on its genetic makeup and background. Additionally, the season it is planted will have effects on its development; those seasons tend to be in the middle of summer and beginning of fall. Sunflower development is classified by a series of vegetative stages and reproductive stages that can be determined by identifying the heads or main branch of a single head or branched head. Helianthus whorl

Phylogeny

The geographical history of this genus accounts for its evolutionary history, with its levels of genetic variation across its gene pool increasing as new hybrids are created both for commercial use and in the wild. As a result, sunflower species are also experiencing a genetic bottleneck as a result of selective breeding for industrial use.

Facing the sun (heliotropism)

Before blooming, ''Helianthus'' plant heads tilt during the day to face the sun. This movement is referred to as

heliotropism Heliotropism, a form of tropism, is the diurnal or seasonal motion of plant parts (flowers or leaves) in response to the direction of the Sun. The habit of some plants to move in the direction of the Sun, a form of tropism, was already known by ...

, which continues for a short time when flower buds form and young ''Helianthus'' heads track the Sun. At night, the flower heads reorient their position and face East in anticipation for the sunrise. Sunflowers move back to their original position between 3am and 6am, and the leaves follow about an hour later. By the time they are mature and reach anthesis, ''Helianthus'' generally stop moving and remain facing east, which lets them be warmed by the rising sun. Historically, this has led to controversy on whether or not ''Helianthus'' is heliotropic, as many scientists have failed to observe movement when studying plants that have already bloomed. This is notably different from heliotropism in leaves, as the moving mechanism for leaves exists in the pulvinus. Since flowers do not have pulvini, the movement is caused by increased growth rate of the stems. The growth rate accumulation of the stem on the east side of the stem gradually pushes the flower from east to west during daytime. This matches with the sun as it rises from the east and falls in the west. At night, the growth rate is higher in the west side of the stem that gradually pushes the flower from the west side back to the east side. In addition, it is not actually the whole plant that changes its direction to face the sun, but the flower itself that bends to be illuminated by the sun rays. The heliotropic movement is caused by growth on the opposite side of the flower, driven by accumulation of growth hormones during Sun exposure. Heliotropism persists on cloudy days when the sun is not shining brightly, meaning that the movement is endogenous as a trained and continuous process. However, flower movement does not occur during long periods of rain or clouds. It also does not occur in a growth chamber when exposed to 16 hours of light or in greenhouses, suggesting that the plants require a directional, moving light source. Helianthus can also discriminate between different types of light. When exposed to different light frequencies, the hypocotyls will bend toward blue light but not red light, depending on the quality of the light source. It is the circadian rhythms and the differences of the stem growth rate that work together and cause the heliotropism of the ''Helianthus''. This is important for attracting pollinators and increasing growth metabolism. Future studies are needed for identifying the exact physiological basis and cellular mechanism for this behavior.

Taxonomy

There are many species recognized in the genus: * '' Helianthus agrestis'' Pollard – southeastern sunflower –

Florida Florida is a state located in the Southeastern region of the United States. Florida is bordered to the west by the Gulf of Mexico, to the northwest by Alabama, to the north by Georgia, to the east by the Bahamas and Atlantic Ocean, a ...

Georgia Georgia most commonly refers to: * Georgia (country), a country in the Caucasus region of Eurasia * Georgia (U.S. state), a state in the Southeast United States Georgia may also refer to: Places Historical states and entities * Related to t ...

* ''

Helianthus ambiguus ''Helianthus ambiguus'' is a North American species of sunflower known by the common name ambiguous sunflower. It is found only in the Great Lakes region of the United States, the states of New York, Michigan, Ohio, and Wisconsin Wisconsi ...

'' Britt. –

Wisconsin Wisconsin () is a state in the upper Midwestern United States. Wisconsin is the 25th-largest state by total area and the 20th-most populous. It is bordered by Minnesota to the west, Iowa to the southwest, Illinois to the south, Lake M ...

Michigan Michigan () is a U.S. state, state in the Great Lakes region, Great Lakes region of the Upper Midwest, upper Midwestern United States. With a population of nearly 10.12 million and an area of nearly , Michigan is the List of U.S. states and ...

Ohio Ohio () is a U.S. state, state in the Midwestern United States, Midwestern region of the United States. Of the List of states and territories of the United States, fifty U.S. states, it is the List of U.S. states and territories by area, 34th-l ...

, New York * '' Helianthus angustifolius'' L. – swamp sunflower –

Texas Texas (, ; Spanish language, Spanish: ''Texas'', ''Tejas'') is a state in the South Central United States, South Central region of the United States. At 268,596 square miles (695,662 km2), and with more than 29.1 million residents in 2 ...

, northern

to southern

Illinois Illinois ( ) is a state in the Midwestern United States. Its largest metropolitan areas include the Chicago metropolitan area, and the Metro East section, of Greater St. Louis. Other smaller metropolitan areas include, Peoria and Roc ...

, Long Island, New York * ''

Helianthus annuus The common sunflower (''Helianthus annuus'') is a large annual forb of the genus ''Helianthus'' grown as a crop for its Sunflower seed, edible oily seeds. Apart from sunflower oil, cooking oil production, it is also used as livestock forage (as ...

'' L. – common sunflower, ''girasol'' – most of United States + Canada * ''

Helianthus anomalus ''Helianthus anomalus'', the western sunflower, is a species of plants in the family Asteraceae, found in the southwestern United States. ''Helianthus anomalus'' is of particular interest due to its genetics. It was produced via hybridization of ...

'' S.F.Blake – western sunflower –

Nevada Nevada ( ; ) is a state in the Western region of the United States. It is bordered by Oregon to the northwest, Idaho to the northeast, California to the west, Arizona to the southeast, and Utah to the east. Nevada is the 7th-most extensive, ...

Utah Utah ( , ) is a state in the Mountain West subregion of the Western United States. Utah is a landlocked U.S. state bordered to its east by Colorado, to its northeast by Wyoming, to its north by Idaho, to its south by Arizona, and to its ...

Arizona Arizona ( ; nv, Hoozdo Hahoodzo ; ood, Alĭ ṣonak ) is a U.S. state, state in the Southwestern United States. It is the list of U.S. states and territories by area, 6th largest and the list of U.S. states and territories by population, 14 ...

New Mexico ) , population_demonym = New Mexican ( es, Neomexicano, Neomejicano, Nuevo Mexicano) , seat = Santa Fe, New Mexico, Santa Fe , LargestCity = Albuquerque, New Mexico, Albuquerque , LargestMetro = Albuquerque metropolitan area, Tiguex , Offi ...

* ''

Helianthus argophyllus ''Helianthus argophyllus'' is a North American species of sunflower known by the common name silverleaf sunflower. It is native to the coastal regions of the US state of Texas, and naturalized in other places (Florida, North Carolina, Argentina, ...

'' Torr. & A.Gray – silverleaf sunflower –

North Carolina North Carolina () is a state in the Southeastern region of the United States. The state is the 28th largest and 9th-most populous of the United States. It is bordered by Virginia to the north, the Atlantic Ocean to the east, Georgia a ...

* '' Helianthus arizonensis'' R.C.Jacks. – Arizona sunflower – Arizona, New Mexico * ''

Helianthus atrorubens ''Helianthus atrorubens'' is a North American species of sunflower known by the common name purpledisc sunflower. It is native to the southeastern United States. It is found in all the coastal states from Louisiana to Virginia, plus the inland s ...

'' L. – purpledisk sunflower –

Louisiana Louisiana , group=pronunciation (French: ''La Louisiane'') is a U.S. state, state in the Deep South and South Central United States, South Central regions of the United States. It is the List of U.S. states and territories by area, 20th-smal ...

Alabama (We dare defend our rights) , anthem = " Alabama" , image_map = Alabama in United States.svg , seat = Montgomery , LargestCity = Huntsville , LargestCounty = Baldwin County , LargestMetro = Greater Birmingham , area_total_km2 = 135,7 ...

, Georgia, Florida,

South Carolina )'' Animis opibusque parati'' ( for, , Latin, Prepared in mind and resources, links=no) , anthem = "Carolina";" South Carolina On My Mind" , Former = Province of South Carolina , seat = Columbia , LargestCity = Charleston , LargestMetro = G ...

, North Carolina,

Tennessee Tennessee ( , ), officially the State of Tennessee, is a landlocked state in the Southeastern region of the United States. Tennessee is the 36th-largest by area and the 15th-most populous of the 50 states. It is bordered by Kentucky to ...

Kentucky Kentucky ( , ), officially the Commonwealth of Kentucky, is a state in the Southeastern region of the United States and one of the states of the Upper South. It borders Illinois, Indiana, and Ohio to the north; West Virginia and Virgini ...

Virginia Virginia, officially the Commonwealth of Virginia, is a state in the Mid-Atlantic and Southeastern regions of the United States, between the East Coast of the United States, Atlantic Coast and the Appalachian Mountains. The geography an ...

* ''

Helianthus bolanderi ''Helianthus bolanderi'' is a species of sunflower known by the common names Bolander's sunflower and serpentine sunflower. It is native to California and Oregon, where it grows mainly in mountainous areas, often in serpentine soils. It has been ...

'' A.Gray – serpentine sunflower –

California California is a state in the Western United States, located along the Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the most populous U.S. state and the 3rd largest by area. It is also the ...

Oregon Oregon () is a state in the Pacific Northwest region of the Western United States. The Columbia River delineates much of Oregon's northern boundary with Washington, while the Snake River delineates much of its eastern boundary with Idah ...

* ''

Helianthus × brevifolius ''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 N ...

'' E.Watson – Texas,

Indiana Indiana () is a U.S. state in the Midwestern United States. It is the 38th-largest by area and the 17th-most populous of the 50 States. Its capital and largest city is Indianapolis. Indiana was admitted to the United States as the 19th ...

, Ohio * '' Helianthus californicus'' DC. – California sunflower –

* ''

Helianthus carnosus ''Helianthus carnosus'' is a rare North American species of sunflower known by the common name lakeside sunflower. It is found only in the northeastern part of the state of Florida in the United States. ''Helianthus carnosus'' is a perennial her ...

'' Small – lakeside sunflower – Florida * ''

Helianthus ciliaris ''Helianthus ciliaris'' is a species of sunflower known by the common names Texas blueweed and yerba parda. ''Helianthus ciliaris'' grows in much of the south-central and southwestern United States (from Texas north to Kansas and west to Califor ...

'' DC. – Texas blueweed – United States: Washington, California, Arizona, New Mexico, Nevada, Utah, Texas, Oklahoma,

Colorado Colorado (, other variants) is a state in the Mountain states, Mountain West subregion of the Western United States. It encompasses most of the Southern Rocky Mountains, as well as the northeastern portion of the Colorado Plateau and the wes ...

Kansas Kansas () is a state in the Midwestern United States. Its capital is Topeka, and its largest city is Wichita. Kansas is a landlocked state bordered by Nebraska to the north; Missouri to the east; Oklahoma to the south; and Colorado to ...

, Illinois; Mexico:

Tamaulipas Tamaulipas (), officially the Free and Sovereign State of Tamaulipas ( es, Estado Libre y Soberano de Tamaulipas), is a state in the northeast region of Mexico; one of the 31 states which, along with Mexico City, comprise the 32 Federal Entiti ...

, Coahuila,

Chihuahua Chihuahua may refer to: Places *Chihuahua (state), a Mexican state **Chihuahua (dog), a breed of dog named after the state **Chihuahua cheese, a type of cheese originating in the state **Chihuahua City, the capital city of the state **Chihuahua Mun ...

Sonora Sonora (), officially Estado Libre y Soberano de Sonora ( en, Free and Sovereign State of Sonora), is one of the 31 states which, along with Mexico City, comprise the Federal Entities of Mexico. The state is divided into 72 municipalities; the ...

* ''

Helianthus cinereus ''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 N ...

'' Small –

Missouri Missouri is a U.S. state, state in the Midwestern United States, Midwestern region of the United States. Ranking List of U.S. states and territories by area, 21st in land area, it is bordered by eight states (tied for the most with Tennessee ...

, Kentucky, Indiana, Ohio * ''

Helianthus coloradensis ''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 N ...

'' Cockerell – prairie sunflower – Colorado, New Mexico * ''

Helianthus cusickii ''Helianthus cusickii'' is a species of sunflower known by the common names Cusick's sunflower and turniproot sunflower. It is native to the western United States from Washington, Oregon, Idaho, northern California, and northwestern Nevada. ''He ...

'' A.Gray – Cusick's sunflower – Washington, Oregon, California,

Idaho Idaho ( ) is a state in the Pacific Northwest region of the Western United States. To the north, it shares a small portion of the Canada–United States border with the province of British Columbia. It borders the states of Montana and W ...

, Nevada * ''

Helianthus debilis ''Helianthus debilis'' is a species of sunflower known by the common names cucumberleaf sunflower, beach sunflower, weak sunflower, and East Coast dune sunflower.Wunderlin, R. P. and B. F. Hansen. 2008''Helianthus debilis''.''Atlas of Florida Va ...

'' Nutt. – cucumberleaf sunflower – Texas to

Maine Maine () is a U.S. state, state in the New England and Northeastern United States, Northeastern regions of the United States. It borders New Hampshire to the west, the Gulf of Maine to the southeast, and the Provinces and territories of Canad ...

Mississippi Mississippi () is a state in the Southeastern region of the United States, bordered to the north by Tennessee; to the east by Alabama; to the south by the Gulf of Mexico; to the southwest by Louisiana; and to the northwest by Arkansas. Mis ...

* ''

Helianthus decapetalus ''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, W ...

'' L. – thinleaf sunflower – eastern United States;

Ontario Ontario ( ; ) is one of the thirteen provinces and territories of Canada.Ontario is located in the geographic eastern half of Canada, but it has historically and politically been considered to be part of Central Canada. Located in Central C ...

Quebec Quebec ( ; )According to the Government of Canada, Canadian government, ''Québec'' (with the acute accent) is the official name in Canadian French and ''Quebec'' (without the accent) is the province's official name in Canadian English is ...

* ''

Helianthus deserticola ''Helianthus deserticola,'' the desert sunflower, is a plant species native to Arizona, Nevada Nevada ( ; ) is a U.S. state, state in the Western United States, Western region of the United States. It is bordered by Oregon to the northwest, ...

'' Heiser – desert sunflower – Arizona, Nevada, Utah * †''

Helianthus diffusus ''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 N ...

'' Sims – Missouri† * ''

Helianthus dissectifolius ''Helianthus dissectifolius'' is a rare species of sunflower, endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that a ...

'' R.C.Jacks. – Mexico * ''

Helianthus divaricatus ''Helianthus divaricatus'', commonly known as the rough sunflower, woodland sunflower, or rough woodland sunflower,Dickinson, T.; Metsger, D.; Bull, J.; & Dickinson, R. (2004). ''ROM Field Guide to Wildflowers of Ontario.'' Toronto:Royal Ontario ...

'' L. – woodland sunflower or rough woodland sunflower – eastern United States; Ontario, Quebec * ''

Helianthus × divariserratus ''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 ...

'' R.W.Long Michigan, Indiana, Ohio,

Connecticut Connecticut () is the southernmost state in the New England region of the Northeastern United States. It is bordered by Rhode Island to the east, Massachusetts to the north, New York to the west, and Long Island Sound to the south. Its cap ...

* ''

Helianthus × doronicoides ''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 ...

'' Lam. – Texas, Oklahoma,

Arkansas Arkansas ( ) is a landlocked state in the South Central United States. It is bordered by Missouri to the north, Tennessee and Mississippi to the east, Louisiana to the south, and Texas and Oklahoma to the west. Its name is from the ...

, Missouri,

Iowa Iowa () is a U.S. state, state in the Midwestern United States, Midwestern region of the United States, bordered by the Mississippi River to the east and the Missouri River and Big Sioux River to the west. It is bordered by six states: Wiscon ...

Minnesota Minnesota () is a state in the upper midwestern region of the United States. It is the 12th largest U.S. state in area and the List of U.S. states and territories by population, 22nd most populous, with over 5.75 million residents. Minne ...

, Illinois, Kentucky, Indiana, Ohio,

Pennsylvania Pennsylvania (; (Pennsylvania Dutch: )), officially the Commonwealth of Pennsylvania, is a state spanning the Mid-Atlantic, Northeastern, Appalachian, and Great Lakes regions of the United States. It borders Delaware to its southeast, Ma ...

, Michigan,

New Jersey New Jersey is a U.S. state, state in the Mid-Atlantic States, Mid-Atlantic and Northeastern United States, Northeastern regions of the United States. It is bordered on the north and east by the state of New York (state), New York; on the ea ...

, Virginia * ''

Helianthus eggertii ''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 be ...

'' Small – Alabama, Kentucky, and Tennessee * ''

Helianthus exilis ''Helianthus exilis'' is a species of sunflower known by the common name serpentine sunflower. It is endemic to northern California (from Siskiyou County south to Napa County and Nevada County), where it grows mainly in mountainous areas, often ...

'' A.Gray – California * '' Helianthus floridanus'' A.Gray ex Chapm. – Florida sunflower – Louisiana, Alabama, Georgia, Florida, South Carolina, North Carolina * '' Helianthus giganteus'' L. – giant sunflower – eastern United States; most of Canada * ''

Helianthus glaucophyllus ''Helianthus glaucophyllus'' is a species of sunflower known by the common name whiteleaf sunflower. It is native to the southeastern United States, in the southern Appalachian Mountains in North Carolina, Tennessee, and South Carolina, in and n ...

'' D.M.Sm – whiteleaf sunflower – Tennessee, South Carolina, North Carolina * ''

Helianthus × glaucus ''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 N ...

'' Small – scattered locales in southeastern United States * ''

Helianthus gracilentus ''Helianthus gracilentus'' is a species of sunflower known by the common name slender sunflower. It is native to central and southern California (from Napa County to San Diego County) and Baja California, where it is a member of the dry wildfire- ...

'' A.Gray – slender sunflower – California * '' Helianthus grosseserratus'' M.Martens – sawtooth sunflower – Great Plains,

Great Lakes The Great Lakes, also called the Great Lakes of North America, are a series of large interconnected freshwater lakes in the mid-east region of North America that connect to the Atlantic Ocean via the Saint Lawrence River. There are five la ...

, Ontario, Quebec * ''

Helianthus heterophyllus ''Helianthus heterophyllus'' is a species of sunflower known by the common names variableleaf sunflower and wetland sunflower. It is native to the coastal plain of the southern United States from Texas to North Carolina. ''Helianthus heterophyll ...

'' Nutt. – variableleaf sunflower – Coastal plain of Texas to North Carolina * '' Helianthus hirsutus'' Raf. – hairy sunflower – central and eastern United States, Ontario * ''Helianthus'' × ''intermedius'' R.W.Long – intermediate sunflower – scattered locales in United States * ''

Helianthus laciniatus ''Helianthus laciniatus'' is a North American species of sunflower known by the common name alkali sunflower. It is found in the southwestern United States (southeastern Arizona, southern New Mexico, western Texas) and north-central Mexico ( Chih ...

'' A.Gray – alkali sunflower – United States: Arizona, New Mexico, Texas; Mexico: Coahuila,

Nuevo León Nuevo León () is a state in the northeast region of Mexico. The state was named after the New Kingdom of León, an administrative territory from the Viceroyalty of New Spain, itself was named after the historic Spanish Kingdom of León. With ...

* ''Helianthus'' × ''laetiflorus'' Pers. – cheerful sunflower, mountain sunflower – scattered in eastern and central United States; Canada * ''

Helianthus laevigatus ''Helianthus laevigatus'' is a North American species of sunflower known by the common name smooth sunflower. It is native to the east-central and southeastern United States from Georgia to Maryland. ''Helianthus laevigatus'' is a perennial he ...

'' Torr. & A.Gray – smooth sunflower – Georgia, South Carolina, North Carolina, Virginia, Maryland,

West Virginia West Virginia is a state in the Appalachian, Mid-Atlantic and Southeastern regions of the United States.The Census Bureau and the Association of American Geographers classify West Virginia as part of the Southern United States while the ...

* ''

Helianthus lenticularis The common sunflower (''Helianthus annuus'') is a large annual plant, annual forb of the genus ''Helianthus'' grown as a crop for its Sunflower seed, edible oily seeds. Apart from sunflower oil, cooking oil production, it is also used as livestoc ...

'' Douglas ex Lindl. California, Texas * ''

Helianthus longifolius ''Helianthus longifolius'' is a North American species of sunflower known by the common name longleaf sunflower. It is native to the southeastern United States (mostly Georgia and Alabama with one isolated population (probably introduced) in wes ...

'' Pursh – longleaf sunflower – Alabama, Georgia, North Carolina * ''

Helianthus × luxurians ''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 N ...

'' (E.Watson) E.Watson –

region * '' Helianthus maximiliani'' Schrad. – Maximillian sunflower – much of United States and Canada * '' Helianthus membranifolius'' Poir. –

French Guiana French Guiana ( or ; french: link=no, Guyane ; gcr, label=French Guianese Creole, Lagwiyann ) is an overseas departments and regions of France, overseas department/region and single territorial collectivity of France on the northern Atlantic ...

* ''

Helianthus microcephalus ''Helianthus microcephalus'' is a perennial species of ''Helianthus'' also known as small woodland sunflower or small-wood sunflower or small-head sunflower or simply as woodland sunflower. It is a native of Northern America, and is to be found g ...

'' Torr. & A.Gray – eastern United States * ''

Helianthus mollis ''Helianthus mollis'' is a species of sunflower known by the common names ashy sunflower, hairy sunflower or downy sunflower. It is widespread across much of the United States and Canada, primarily the Great Lakes region from Ontario south to Te ...

'' Lam. – downy sunflower, ashy sunflower – Ontario, eastern and central United States * ''

Helianthus multiflorus The common sunflower (''Helianthus annuus'') is a large annual forb of the genus ''Helianthus'' grown as a crop for its edible oily seeds. Apart from cooking oil production, it is also used as livestock forage (as a meal or a silage plant), as ...

'' L. – manyflower sunflower – Ohio * ''

Helianthus navarri ''Helianthus navarri'' is a species of sunflower in the family Asteraceae. It is native to Chile Chile, officially the Republic of Chile, is a country in the western part of South America. It is the southernmost country in the world, and ...

'' Phil. –

Chile Chile, officially the Republic of Chile, is a country in the western part of South America. It is the southernmost country in the world, and the closest to Antarctica, occupying a long and narrow strip of land between the Andes to the eas ...

* ''

Helianthus neglectus ''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 neglectus'' grows on sand dunes and other sa ...

'' Heiser – neglected sunflower – New Mexico, Texas * ''

Helianthus niveus ''Helianthus niveus'' is a species of sunflower known by the common names showy sunflower and snowy sunflower. It is native to northern Mexico (Sonora, Baja California, Baja California Sur) and the Southwestern United States (Southern California, ...

'' (Benth.) Brandegee – showy sunflower – United States: California,

; Mexico:

Baja California Baja California (; 'Lower California'), officially the Free and Sovereign State of Baja California ( es, Estado Libre y Soberano de Baja California), is a state in Mexico. It is the northernmost and westernmost of the 32 federal entities of Mex ...

, Baja California Sur * '' Helianthus nuttallii'' Torr. & A.Gray – western and central United States, Canada * ''

Helianthus occidentalis ''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 ...

'' Riddell – fewleaf sunflower, western sunflower – Great Lakes region, scattered in southeastern United States * ''

Helianthus × orgyaloides ''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 N ...

'' Cockerell – Colorado, Kansas * ''

Helianthus paradoxus ''Helianthus paradoxus'', the paradox sunflower, puzzle sunflower or Pecos sunflower, is a threatened species of sunflower found only in west Texas, Utah, and New Mexico salt marshes by the edges of inland salt lakes and salt flats. ''Helianthus ...

'' Heiser – paradox sunflower – Utah, New Mexico, Texas * ''

Helianthus pauciflorus ''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 ...

'' Nutt. – stiff sunflower – central United States, Canada * '' Helianthus petiolaris'' Nutt. – prairie sunflower, lesser sunflower – much of United States, Canada * ''

Helianthus porteri ''Helianthus porteri'' is a species of sunflower known by the common names Porter's sunflower, Stone Mountain daisy and Confederate daisy. The term "daisy" is a imprecise because the species is a sunflower (''Helianthus'') rather than a daisy (' ...

'' (A.Gray) Pruski – Porter's sunflower – Alabama, Georgia, South Carolina, North Carolina * '' Helianthus praecox'' Engelm. & A.Gray Texas sunflower – Texas * †''

Helianthus praetermissus ''Helianthus praetermissus'' is a rare and probably extinct North American species of sunflower, with the common names New Mexico sunflower and lost sunflower. It is known from only one specimen collected in 1851 in Cibola County in western New M ...

'' – New Mexico sunflower – New Mexico† * ''

Helianthus pumilus ''Helianthus pumilus'' is a North American species of sunflower known by the common name little sunflower or bush sunflower. It is found in the western United States, primarily the Rocky Mountain region of Montana, Wyoming, and Colorado, with a f ...

'' Nutt. – little sunflower – Colorado,

Wyoming Wyoming () is a state in the Mountain West subregion of the Western United States. It is bordered by Montana to the north and northwest, South Dakota and Nebraska to the east, Idaho to the west, Utah to the southwest, and Colorado to the sou ...

Montana Montana () is a U.S. state, state in the Mountain states, Mountain West List of regions of the United States#Census Bureau-designated regions and divisions, division of the Western United States. It is bordered by Idaho to the west, North ...

, Utah, Idaho * ''

Helianthus radula ''Helianthus radula'' is a North American species of sunflower known by the common name rayless sunflower or pineland sunflower. It is native to the southeastern United States from eastern Louisiana to South Carolina. ''Helianthus radula'' grows ...

'' (Pursh) Torr. & A.Gray – rayless sunflower – Louisiana, Mississippi, Alabama, Georgia, South Carolina, Florida * ''

Helianthus resinosus ''Helianthus resinosus'' is a North American species of sunflower known by the common name sunflower. It is native to the southeastern United States from Mississippi to North Carolina. ''Helianthus resinosus '' grows in open swamps and meadows, ...

'' Small – resindot sunflower – Mississippi, Alabama, Georgia, South Carolina, North Carolina, Florida * ''

Helianthus salicifolius ''Helianthus salicifolius'' is a North American species of sunflower known by the common name willowleaf sunflower. It is native to the central United States, primarily in the Great Plains and Ozark Plateau (states of Missouri, Kansas, Oklahom ...

'' A.Dietr. – willowleaf sunflower – Texas, Oklahoma, Kansas, Missouri, Illinois, Wisconsin, Ohio, Pennsylvania, New York * ''