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 Cooking oil is plant, animal, or synthetic liquid fat used in frying, baking, and other types of cooking. It is also used in food preparation and flavoring not involving heat, such as salad dressings and bread dips, and may be called edible oil. ...

production, it is also used as livestock forage (as a meal or a silage plant), 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 (flower head) atop an unbranched stem. The

binomial name In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bot ...

''Helianthus annuus'' is derived from the Greek ''Helios'' 'sun' and ''anthos'' 'flower', while the epithet ''annuus'' means 'annual' in Latin. The plant was first domesticated in the

Americas The Americas, which are sometimes collectively called America, are a landmass comprising the totality of North and South America. The Americas make up most of the land in Earth's Western Hemisphere and comprise the New World. Along with th ...

. Sunflower seeds were brought to Europe from the Americas in the 16th century, where, along with sunflower oil, they became a widespread cooking ingredient. With time, bulk of industrial-scale production has shifted to Eastern Europe, and () Russia and Ukraine together produce over half of worldwide seed production.

Description

The plant has an erect rough-hairy stem, reaching typical heights of . The tallest sunflower on record achieved . Sunflower leaves are broad, coarsely toothed, rough and mostly alternate; those near the bottom are largest and commonly heart-shaped.

Flower

The plant flowers in summer. What is often called the " flower" of the sunflower is actually a "flower head" ( pseudanthium), wide, of numerous small individual five-petaled flowers (" florets"). The outer flowers, which resemble petals, are called ray flowers. Each "petal" consists of a

ligule A ligule (from "strap", variant of ''lingula'', from ''lingua'' "tongue") is a thin outgrowth at the junction of leaf and leafstalk of many grasses (Poaceae) and sedges. A ligule is also a strap-shaped extension of the corolla, such as that of a ...

composed of fused petals of an asymmetrical ray flower. They are sexually sterile and may be yellow, red, orange, or other colors. The spirally arranged flowers in the center of the head are called disk flowers. These mature into fruit (sunflower "seeds"). Prairie sunflower (''H. petiolaris'') is similar in appearance to the wild common sunflower; the scales in its central disk are tipped by white hairs.

Heliotropism

A common misconception is that flowering sunflower heads track the Sun across the sky. Although immature flower buds exhibit this behaviour, the mature flowering heads point in a fixed (and typically easterly) direction throughout the day. This old misconception was disputed in 1597 by the English botanist John Gerard, who grew sunflowers in his famous herbal garden: " omehave reported it to turn with the Sun, the which I could never observe, although I have endeavored to find out the truth of it." Popular botany book in 17th century England The uniform alignment of sunflower heads in a field might give some people the false impression that the flowers are tracking the Sun. This alignment results from

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 t ...

in an earlier development stage, the young flower stage, before full maturity of flower heads ( anthesis). Young sunflowers orient themselves in the direction of the sun. At dawn the head of the flower faces east and moves west throughout the day. When sunflowers reach full maturity they no longer follow the sun, and continuously face east. Young flowers reorient overnight to face east in anticipation of the morning. Their heliotropic motion is a

circadian A circadian rhythm (), or circadian cycle, is a natural, internal process that regulates the sleep–wake cycle and repeats roughly every 24 hours. It can refer to any process that originates within an organism (i.e., endogenous) and responds to ...

rhythm, synchronized by the sun, which continues if the sun disappears on cloudy days or if plants are moved to constant light. They are able to regulate their circadian rhythm in response to the blue-light emitted by a light source. If a sunflower plant in the bud stage is rotated 180°, the bud will be turning away from the sun for a few days, as resynchronization with the sun takes time. When growth of the flower stalk stops and the flower is mature, the heliotropism also stops and the flower faces east from that moment onward. This eastward orientation allows rapid warming in the morning and, as a result, an increase in pollinator visits. Sunflowers do not have a

pulvinus A pulvinus (pl. ''pulvini'') is a joint-like thickening at the base of a plant leaf or leaflet that facilitates growth-independent movement. Pulvini are common, for example, in members of the bean family Fabaceae (Leguminosae) and the prayer plant ...

below their inflorescence. A pulvinus is a flexible segment in the leaf stalks (petiole) of some plant species and functions as a 'joint'. It effectuates leaf motion due to reversible changes in turgor pressure, which occurs without growth. The sensitive plant's closing leaves are a good example of reversible leaf movement via pulvinuli.

Floret arrangement

Generally, each floret is oriented toward the next by approximately the

golden angle In geometry, the golden angle is the smaller of the two angles created by sectioning the circumference of a circle according to the golden ratio; that is, into two arcs such that the ratio of the length of the smaller arc to the length of the l ...

, 137.5°, producing a pattern of interconnecting

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:Fibonacci numbers. Typically, there are 34 spirals in one direction and 55 in the other; however, in a very large sunflower head there could be 89 in one direction and 144 in the other. This pattern produces the most efficient packing of seeds mathematically possible within the flower head. A model for the pattern of florets in the head of a sunflower was proposed by H. Vogel in 1979. This is expressed in polar coordinates :

r=c \sqrt,

\theta=n \times 137.5^,

where θ is the angle, ''r'' is the radius or distance from the center, and ''n'' is the index number of the floret and ''c'' is a constant scaling factor. It is a form of Fermat's spiral. The angle 137.5° is related to the golden ratio (55/144 of a circular angle, where 55 and 144 are Fibonacci numbers) and gives a close packing of florets. This model has been used to produce computer generated representations of sunflowers.

Genome

The sunflower genome is

diploid Ploidy () is the number of complete sets of chromosomes in a cell, and hence the number of possible alleles for autosomal and pseudoautosomal genes. Sets of chromosomes refer to the number of maternal and paternal chromosome copies, respectively ...

with a base chromosome number of 17 and an estimated genome size of 2,871–3,189 million

base pair A base pair (bp) is a fundamental unit of double-stranded nucleic acids consisting of two nucleobases bound to each other by hydrogen bonds. They form the building blocks of the DNA double helix and contribute to the folded structure of both DNA ...

s. Some sources claim its true size is around 3.5 billion base pairs (slightly larger than the human genome).

Distribution and habitat

The plant was first domesticated in the

. Sunflowers grow best in fertile, moist, well-drained soil with heavy mulch. They often appear on dry open areas and foothills.

Ecology

Threats and diseases

One of the major threats that sunflowers face today is '' Fusarium'', a filamentous fungus that is found largely in soil and plants. It is a pathogen that over the years has caused an increasing amount of damage and loss of sunflower crops, some as extensive as 80% of damaged crops.Gontcharov, SV. Antonova, TS. and Saukova, SL. 2006. Sunflower breeding for resistance to fusarium. Helia ccessed September 14, 2014 29 (45): 49-54. Downy mildew is another disease to which sunflowers are susceptible. Its susceptibility to downy mildew is particular high due to the sunflower's way of growth and development. Sunflower seeds are generally planted only an inch deep in the ground. When such shallow planting is done in moist and soaked earth or soil, it increases the chances of diseases such as downy mildew. Another major threat to sunflower crops is broomrape, a parasite that attacks the root of the sunflower and causes extensive damage to sunflower crops, as high as 100%.

Cultivation

In commercial planting, seeds are planted apart and deep.

History

Common sunflower was one of several plants cultivated by Native Americans in

prehistoric Prehistory, also known as pre-literary history, is the period of human history between the use of the first stone tools by hominins 3.3 million years ago and the beginning of recorded history with the invention of writing systems. The use of ...

North America as part of the Eastern Agricultural Complex. Although it was commonly accepted that the sunflower was first domesticated in what is now the southeastern US, roughly 5,000 years ago, there is evidence that it was first domesticated in Mexico around 2600 BCE. These crops were found in Tabasco, Mexico, at the San Andres dig site. The earliest known examples in the US of a fully domesticated sunflower have been found in Tennessee, and date to around 2300 BCE. Other very early examples come from rockshelter sites in Eastern Kentucky. Many indigenous American peoples used the sunflower as the symbol of their

solar deity A solar deity or sun deity is a deity who represents the Sun, or an aspect of it. Such deities are usually associated with power and strength. Solar deities and Sun worship can be found throughout most of recorded history in various forms. The ...

, including the

Aztecs The Aztecs () were a Mesoamerican culture that flourished in central Mexico in the post-classic period from 1300 to 1521. The Aztec people included different Indigenous peoples of Mexico, ethnic groups of central Mexico, particularly those g ...

and the Otomi of Mexico and the Incas in South America. In 1510, early Spanish explorers encountered the sunflower in the Americas and carried its seeds back to Europe. Of the four plants known to have been domesticated in eastern North America and to have become important agricultural commodities, the sunflower is currently the most economically important. Research of phylogeographic relations and population demographic patterns across sunflowers has demonstrated that earlier cultivated sunflowers form a

clade A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, ...

from wild populations from the Great Plains, which indicates that there was a single domestication event in central North America. Following the cultivated sunflower's origin, it may have gone through significant bottlenecks dating back to ~5,000 years ago. In the 16th century the first crop breeds were brought from America to Europe by explorers. Domestic sunflower seeds have been found in Mexico, dating to 2100 BCE. Native American people grew sunflowers as a crop from Mexico to Southern Canada. They then were introduced to the Russian Empire, where oilseed cultivators were located, and the flowers were developed and grown on an industrial scale. The Russian Empire reintroduced this oilseed cultivation process to North America in the mid-20th century; North America began their commercial era of sunflower production and breeding. New breeds of the ''Helianthus spp.'' began to become more prominent in new geographical areas. During the 18th century, the use of sunflower oil became very popular in Russia, particularly with members of the Russian Orthodox Church, because only plant-based fats were allowed during

Lent Lent ( la, Quadragesima, 'Fortieth') is a solemn religious observance in the liturgical calendar commemorating the 40 days Jesus spent fasting in the desert and enduring temptation by Satan, according to the Gospels of Matthew, Mark and Luke ...

, according to fasting traditions. In the early 19th century, it was first commercialized in the village of Alexeyevka in Voronezh Governorate by the merchant named Daniil Bokaryov, who developed a technology suitable for its large-scale extraction, and quickly spread around. The town's coat of arms has included an image of a sunflower ever since.

Production

In 2020, world production of sunflower seeds was 50 million tonnes, led by Russia and Ukraine with 53% combined of the total (table).

Fertilizer use

Researchers have analyzed the impact of various nitrogen-based fertilizers on the growth of sunflowers. Ammonium nitrate was found to produce better nitrogen absorption than urea, which performed better in low-temperature areas.

Production in Brazil

In Brazil, a unique system of production called the soybean-sunflower system is used: sunflowers are planted first, and then soybean crops follow, reducing idle periods and increasing total sunflower production and profitability. Sunflowers are usually planted in the extreme southern or northern regions of the country. Frequently, in the southern regions, sunflowers are grown in the beginning of rainy seasons, and soybeans can then be planted in the summer. Researchers have concluded that the soybean-sunflower method of plantation could be further improved through changes in fertilizer use. The current method has been shown to have positive environmental impacts.

Hybrids and cultivars

In today's market, most of the sunflower seeds provided or grown by farmers are hybrids. Hybrids or hybridized sunflowers are produced by cross-breeding different types and species, for example cultivated sunflowers with wild species. By doing so, new genetic recombinations are obtained ultimately leading to the production of new hybrid species. These hybrid species generally have a higher fitness and carry properties or characteristics that farmers look for, such as resistance to pathogens. Hybrid, ''Helianthus annuus dwarf2'' does not contain the hormone gibberellin and does not display heliotropic behavior. Plants treated with an external application of the hormone display a temporary restoration of elongation growth patterns. This growth pattern diminished by 35% 7–14 days after final treatment. Hybrid male sterile and male fertile flowers that display heterogeneity have a low crossover of honeybee visitation. Sensory cues such as pollen odor, diameter of seed head, and height may influence pollinator visitation of pollinators that display constancy behavior patterns. Sunflowers are grown as ornamentals in a domestic setting. Being easy to grow and producing spectacular results in any good, moist soil in full sun, they are a favourite subject for children. A large number of cultivars, of varying size and colour, are now available to grow from seed. The following are cultivars of sunflowers (those marked have gained the Royal Horticultural Society's

Award of Garden Merit The Award of Garden Merit (AGM) is a long-established annual award for plants by the British Royal Horticultural Society (RHS). It is based on assessment of the plants' performance under UK growing conditions. History The Award of Garden Merit ...

):- Helianthus annuus prado red.jpg, Prado Red Sunflower3-2012.jpg, Mammoth Russian Helianthus annuus (cultivar) 02.jpg, Teddy Bear

Uses

Sunflower "whole seed" (fruit) are sold as a snack food, raw or after roasting in ovens, with or without salt and/or seasonings added. Sunflowers can be processed into a peanut butter alternative,

sunflower butter Sunflower butter, also known as sunflower seed butter, is a food paste made from sunflower seeds. Sunflower butter is commonly used as a substitute for peanut butter when allergies are a concern. History U.S. commercial versions of sunflower butt ...

. It is also sold as food for birds and can be used directly in cooking and salads. Native Americans had multiple uses for sunflowers in the past, such as in bread, medical ointments, dyes and body paints. Sunflower oil, extracted from the seeds, is used for cooking, as a carrier oil and to produce

margarine Margarine (, also , ) is a spread used for flavoring, baking, and cooking. It is most often used as a substitute for butter. Although originally made from animal fats, most margarine consumed today is made from vegetable oil. The spread was orig ...

and biodiesel, as it is cheaper than

olive oil Olive oil is a liquid fat obtained from olives (the fruit of ''Olea europaea''; family Oleaceae), a traditional tree crop of the Mediterranean Basin, produced by pressing whole olives and extracting the oil. It is commonly used in cooking: f ...

. A range of sunflower varieties exist with differing fatty acid compositions; some "high-oleic" types contain a higher level of monounsaturated fats in their oil than even olive oil. The oil is also sometimes used in soap. After World War I, during the Russian Civil War, people in Ukraine used sunflower seed oil in lamps as a substitute for kerosene due to shortages. The light from such a lamp has been described as "miserable" and "smoky." The cake remaining after the seeds have been processed for oil is used as a livestock feed. The hulls resulting from the dehulling of the seeds before oil extraction can also be fed to domestic animals. Some recently developed cultivars have drooping heads. These cultivars are less attractive to

gardeners A gardener is someone who practices gardening, either professionally or as a hobby. Description A gardener is any person involved in gardening, arguably the oldest occupation, from the hobbyist in a residential garden, the home-owner supplem ...

growing the flowers as ornamental plants, but appeal to farmers, because they reduce bird damage and losses from some plant diseases. Sunflowers also produce latex, and are the subject of experiments to improve their suitability as an alternative crop for producing hypoallergenic rubber. Traditionally, several Native American groups planted sunflowers on the north edges of their gardens as a "fourth sister" to the better-known three sisters combination of

corn Maize ( ; ''Zea mays'' subsp. ''mays'', from es, maíz after tnq, mahiz), also known as corn (North American and Australian English), is a cereal grain first domesticated by indigenous peoples in southern Mexico about 10,000 years ago. Th ...

, beans, and squash. Annual species are often planted for their

allelopathic Allelopathy is a biological phenomenon by which an organism produces one or more biochemicals that influence the germination, growth, survival, and reproduction of other organisms. These biochemicals are known as allelochemicals and can have ben ...

properties. It was also used by Native Americans to dress hair. Among the

Zuni people The Zuni ( zun, A:shiwi; formerly spelled ''Zuñi'') are Native American Pueblo peoples native to the Zuni River valley. The Zuni are a Federally recognized tribe and most live in the Pueblo of Zuni on the Zuni River, a tributary of the Lit ...

, the fresh or dried root is chewed by the medicine man before sucking venom from a snakebite and applying a poultice to the wound. This compound poultice of the root is applied with much ceremony to rattlesnake bites. However, for commercial farmers growing other commodity crops, the wild sunflower is often considered a weed. Especially in the Midwestern US, wild (perennial) species are often found in corn and soybean fields and can decrease yields. The decrease in yield can be attributed to the production of phenolic compounds which are used to reduce competition for nutrients in nutrient-poor growing areas of the common sunflower. Sunflowers can be used in phytoremediation to extract toxic ingredients from soil, such as lead, arsenic and uranium, and used in rhizofiltration to neutralize

radionuclide A radionuclide (radioactive nuclide, radioisotope or radioactive isotope) is a nuclide that has excess nuclear energy, making it unstable. This excess energy can be used in one of three ways: emitted from the nucleus as gamma radiation; transfer ...

s and other toxic ingredients and harmful bacteria from water. They were used to remove caesium-137 and strontium-90 from a nearby pond after the

Chernobyl disaster The Chernobyl disaster was a nuclear accident that occurred on 26 April 1986 at the No. 4 reactor in the Chernobyl Nuclear Power Plant, near the city of Pripyat in the north of the Ukrainian SSR in the Soviet Union. It is one of only two nuc ...

, and a similar campaign was mounted in response to the

Fukushima Daiichi nuclear disaster The was a nuclear accident in 2011 at the Fukushima Daiichi Nuclear Power Plant in Ōkuma, Fukushima, Japan. The proximate cause of the disaster was the 2011 Tōhoku earthquake and tsunami, which occurred on the afternoon of 11 March 2011 and ...

. Sunflower Seeds Kaldari.jpg, Seed dehulled (left) and with hull (right) SunflowerYield.png, Worldwide sunflower output Helianthus whorl.jpg, Head displaying florets in spirals of 34 and 55 around the outside Helianthus annuus pollen 1.jpg, Pollen

Culture

Vincent Van Gogh - Three Sunflowers F453

During the 19th century, it was believed that nearby plants of the species would protect a home from malaria. The Zuni people use the blossoms ceremonially for anthropic worship. Sunflowers were also worshipped by the Incas because they viewed it as a symbol for the Sun. The sunflower is the national flower of Ukraine. During the

2022 Russian invasion of Ukraine On 24 February 2022, in a major escalation of the Russo-Ukrainian War, which began in 2014. The invasion has resulted in tens of thousands of deaths on both sides. It has caused Europe's largest refugee crisis since World War II. An ...

, a video widely shared on social media showed a Ukrainian woman confronting a Russian soldier, telling the latter to "take these seeds and put them in your pockets so at least sunflowers will grow when you all lie down here". The sunflower has since become a global symbol of resistance, unity, and hope. The sunflower is also the

state flower This is a list of U.S. state, federal district, and territory flowers. See also *List of U.S. state trees * Lists of U.S. state insignia References External linksList of state flowers {{USStateLists * U.S. state flowers Flowers ...

of the US state of Kansas, and one of the city flowers of

Kitakyūshū is a city located in Fukuoka Prefecture, Japan. As of June 1, 2019, Kitakyushu has an estimated population of 940,978, making it the second-largest city in both Fukuoka Prefecture and the island of Kyushu after the city of Fukuoka. It is one of ...

Japan Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...

. The flowers are the subject of Vincent van Gogh's ''Sunflowers'' series of still-life paintings. During the late 19th century, the flower was used as the symbol of the

Aesthetic Movement Aestheticism (also the Aesthetic movement) was an art movement in the late 19th century which privileged the aesthetic value of literature, music and the arts over their socio-political functions. According to Aestheticism, art should be prod ...

. The sunflower is often used as a symbol of

green ideology Green politics, or ecopolitics, is a political ideology that aims to foster an ecologically sustainable society often, but not always, rooted in environmentalism, nonviolence, social justice and grassroots democracy. Wall 2010. p. 12-13. It b ...

. The sunflower is also the symbol of the Vegan Society. The sunflower was chosen as the symbol of the Spiritualist Church for many reasons, but mostly because it turns toward the sun as "Spiritualism turns toward the light of truth". As stated earlier in the article, this is in fact, not true. Modern Spiritualists often have art or jewelry with sunflower designs. The sunflower is the symbol behind the

Sunflower Movement 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 b ...

, a 2014 mass protest in Taiwan. In July 2015, viable seeds were acquired from the field where Malaysia Airlines Flight 17 crashed on a year earlier and were grown in tribute to the 15 Dutch residents of

Hilversum Hilversum () is a city and municipality in the province of North Holland, Netherlands. Located in the heart of the Gooi, it is the largest urban centre in that area. It is surrounded by heathland, woods, meadows, lakes, and smaller towns. Hilvers ...

who were killed. Earlier that year,

Fairfax Fairfax may refer to: Places United States * Fairfax, California * Fairfax Avenue, a major thoroughfare in Los Angeles, California * Fairfax District, Los Angeles, California, centered on Fairfax Avenue * Fairfax, Georgia * Fairfax, Indiana * Fa ...

chief correspondent Paul McGeough and photographer

Kate Geraghty Kate Geraghty (born 1972) is an Australian war photographer, and photojournalist for ''The Sydney Morning Herald'', and ''The Age'' and five time Walkley winner. Career Geraghty started photographing professionally at Albury-Wodonga's ''The Bor ...

had collected 1.5 kg of sunflower seeds from the wreck site for family and friends of the 38 Australian victims, who aimed to give them a poignant symbol of hope. On May 13, 2021, during the National Costume competition of the Miss Universe 2020 beauty pageant, Miss Dominican Republic Kimberly Jiménez wore a "Goddess of Sunflowers" costume covered in gold and yellow rhinestones that included several real sunflowers sewn onto the fabric, although one of them fell off and was lying behind her on the stage during her performance. Modern stories often claim that in Greek mythology, the nymph Clytie transformed into a sunflower when she pined after her former lover

Helios In ancient Greek religion and Greek mythology, mythology, Helios (; grc, , , Sun; Homeric Greek: ) is the deity, god and personification of the Sun (Solar deity). His name is also Latinized as Helius, and he is often given the epithets Hyper ...

, the

god of the sun A solar deity or sun deity is a deity who represents the Sun, or an aspect of it. Such deities are usually associated with power and strength. Solar deities and Sun worship can be found throughout most of recorded history in various forms. The ...

, who spurned her and left her for another. However, sunflowers are not native to Greece or Italy, but to

North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...

. The original story is about another flower, the heliotropium.

References

Sources

* Pope, Kevin; Pohl, Mary E. D.; Jones, John G.; Lentz, David L.; von Nagy, Christopher; Vega, Francisco J.; Quitmyer Irvy R. (18 May 2001).
Origin and Environmental Setting of Ancient Agriculture in the Lowlands of Mesoamerica
. '' Science'', 292(5520):1370–1373. * Shosteck, Robert (1974) ''Flowers and Plants: An International Lexicon with Biographical Notes''. New York: Quadrangle/The New York Times Book Co. . *

External links

*
National Sunflower Association

Sunflowerseed
��USDA Economic Research Service. Summary of sunflower production, trade, and consumption and links to relevant USDA reports.

��New Crop Resource Online Program, Purdue University {{Taxonbar, from=Q171497 annuus Flora of Mexico Flora of the United States Annual plants Edible nuts and seeds Energy crops Garden plants of North America Phytoremediation plants Agriculture in Mesoamerica Crops originating from Pre-Columbian North America Plants used in Native American cuisine Plants used in traditional Native American medicine Pre-Columbian California cuisine Pre-Columbian Great Plains cuisine Plants described in 1753 Symbols of Kansas National symbols of Ukraine Taxa named by Carl Linnaeus Oil seeds Flora of Malta