Sunflower

Sunflower

Overview
Sunflower is an annual plant
Annual plant
An annual plant is a plant that usually germinates, flowers, and dies in a year or season. True annuals will only live longer than a year if they are prevented from setting seed...

 native to the Americas
Americas
The Americas, or America , are lands in the Western hemisphere, also known as the New World. In English, the plural form the Americas is often used to refer to the landmasses of North America and South America with their associated islands and regions, while the singular form America is primarily...

. It possesses a large inflorescence
Inflorescence
An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Strictly, it is the part of the shoot of seed plants where flowers are formed and which is accordingly modified...

 (flowering head). The sunflower got its name from its huge, fiery blooms, whose shape and image is often used to depict the sun. The sunflower has a rough, hairy stem, broad, coarsely toothed, rough leaves and circular heads of flowers. The heads consist of 1,000-2,000 individual flowers joined together by a receptacle base.

From the Americas, sunflower seeds were brought to Europe in the 16th century, where, along with sunflower oil
Sunflower oil
Sunflower oil is the non-volatile oil expressed from sunflower seeds. Sunflower oil is commonly used in food as a frying oil, and in cosmetic formulations as an emollient. Sunflower oil was first industrially produced in 1835 in the Russian Empire.- Composition :Sunflower oil is mainly a...

, they became a widespread cooking ingredient.
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Encyclopedia
Sunflower is an annual plant
Annual plant
An annual plant is a plant that usually germinates, flowers, and dies in a year or season. True annuals will only live longer than a year if they are prevented from setting seed...

 native to the Americas
Americas
The Americas, or America , are lands in the Western hemisphere, also known as the New World. In English, the plural form the Americas is often used to refer to the landmasses of North America and South America with their associated islands and regions, while the singular form America is primarily...

. It possesses a large inflorescence
Inflorescence
An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Strictly, it is the part of the shoot of seed plants where flowers are formed and which is accordingly modified...

 (flowering head). The sunflower got its name from its huge, fiery blooms, whose shape and image is often used to depict the sun. The sunflower has a rough, hairy stem, broad, coarsely toothed, rough leaves and circular heads of flowers. The heads consist of 1,000-2,000 individual flowers joined together by a receptacle base.

From the Americas, sunflower seeds were brought to Europe in the 16th century, where, along with sunflower oil
Sunflower oil
Sunflower oil is the non-volatile oil expressed from sunflower seeds. Sunflower oil is commonly used in food as a frying oil, and in cosmetic formulations as an emollient. Sunflower oil was first industrially produced in 1835 in the Russian Empire.- Composition :Sunflower oil is mainly a...

, they became a widespread cooking ingredient. Leaves of the sunflower can be used as cattle feed, while the stems contain a fibre which may be used in paper production.

Description



What is usually called the "flower
Flower
A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants . The biological function of a flower is to effect reproduction, usually by providing a mechanism for the union of sperm with eggs...

" on a mature sunflower is actually a "flower head
Head (botany)
The capitulum is considered the most derived form of inflorescence. Flower heads found outside Asteraceae show lesser degrees of specialization....

" (also known as a "composite flower") of numerous florets, (small flowers) crowded together. The outer petal-bearing florets are the sterile ray florets and can be yellow, red, orange, or other colors. The florets inside the circular head are called disc florets, which mature into seeds
Sunflower seed
The sunflower seed is the fruit of the sunflower . The term "sunflower seed" is actually a misnomer when applied to the seed in its pericarp . Botanically speaking, it is more properly referred to as an achene. When dehulled, the edible remainder is called the sunflower kernel.There are three types...

.

The flower petals within the sunflower's cluster are usually in a a spiral pattern
Phyllotaxis
In botany, phyllotaxis or phyllotaxy is the arrangement of leaves on a plant stem .- Pattern structure :...

. Generally, each floret is oriented toward the next by approximately the golden angle
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 section; that is, into two arcs such that the ratio of the length of the larger arc to the length of the smaller arc is the same as the ratio of the full...

, 137.5°, producing a pattern of interconnecting spiral
Spiral
In mathematics, a spiral is a curve which emanates from a central point, getting progressively farther away as it revolves around the point.-Spiral or helix:...

s, where the number of left spirals and the number of right spirals are successive Fibonacci number
Fibonacci number
In mathematics, the Fibonacci numbers are the numbers in the following integer sequence:0,\;1,\;1,\;2,\;3,\;5,\;8,\;13,\;21,\;34,\;55,\;89,\;144,\; \ldots\; ....

s. Typically, there are 34 spirals in one direction and 55 in the other; on a very large sunflower there could be 89 in one direction and 144 in the other. This pattern produces the most efficient packing of seeds within the flower head.

Sunflowers most commonly grow to heights between 1.5 and 3.5 m (5–12 ft). Scientific literature reports that a 12 m (40 ft), traditional, single-head, sunflower plant was grown in Padua
Padua
Padua is a city and comune in the Veneto, northern Italy. It is the capital of the province of Padua and the economic and communications hub of the area. Padua's population is 212,500 . The city is sometimes included, with Venice and Treviso, in the Padua-Treviso-Venice Metropolitan Area, having...

 in 1567. The same seed lot grew almost 8 m (26 ft) at other times and places, including Madrid
Madrid
Madrid is the capital and largest city of Spain. The population of the city is roughly 3.3 million and the entire population of the Madrid metropolitan area is calculated to be 6.271 million. It is the third largest city in the European Union, after London and Berlin, and its metropolitan...

. During the 20th century, heights of over 8 m have been achieved in both the Netherlands
Netherlands
The Netherlands is a constituent country of the Kingdom of the Netherlands, located mainly in North-West Europe and with several islands in the Caribbean. Mainland Netherlands borders the North Sea to the north and west, Belgium to the south, and Germany to the east, and shares maritime borders...

 and Ontario
Ontario
Ontario is a province of Canada, located in east-central Canada. It is Canada's most populous province and second largest in total area. It is home to the nation's most populous city, Toronto, and the nation's capital, Ottawa....

, Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...

.

Heliotropism



A common misconception is that sunflowers track the sun. In fact, mature flowerheads typically face east and do not move. The leaves and buds of young sunflowers do exhibit heliotropism
Heliotropism
Heliotropism is the diurnal motion of plant parts in response to the direction of the sun.It is found in some members of family Malvacea e.g Malva or Lavetara...

 (sun turning). Their orientation changes from east to west during the course of a day. The movements become a circadian response and when plants are rotated 180 degrees, the old response pattern is still followed for a few days, with leaf orientation changing from west to east instead. The leaf and flowerhead bud phototropism
Phototropism
Phototropism is directional growth in which the direction of growth is determined by the direction of the light source. In other words, it is the growth and response to a light stimulus. Phototropism is most often observed in plants, but can also occur in other organisms such as fungi...

 occurs while the leaf petioles and stems are still actively growing, but once mature, the movements stop. These movements involve the petioles bending or twisting during the day then unbending or untwisting at night.

History



The sunflower is native to Central America
Central America
Central America is the central geographic region of the Americas. It is the southernmost, isthmian portion of the North American continent, which connects with South America on the southeast. When considered part of the unified continental model, it is considered a subcontinent...

. The evidence thus far is that it was first domesticated
Agriculture in Mesoamerica
Agriculture in Mesoamerica dates to the Archaic period of Mesoamerican chronology . During this period, many of the hunter gatherer micro-bands in the region began to cultivate wild plants...

 in Mesoamerica
Mesoamerica
Mesoamerica is a region and culture area in the Americas, extending approximately from central Mexico to Belize, Guatemala, El Salvador, Honduras, Nicaragua, and Costa Rica, within which a number of pre-Columbian societies flourished before the Spanish colonization of the Americas in the 15th and...

, present day Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...

, by at least 2600 BC. It may have been domesticated a second time in the middle Mississippi Valley, or been introduced there from Mexico at an early date, as maize
Maize
Maize known in many English-speaking countries as corn or mielie/mealie, is a grain domesticated by indigenous peoples in Mesoamerica in prehistoric times. The leafy stalk produces ears which contain seeds called kernels. Though technically a grain, maize kernels are used in cooking as a vegetable...

 was. The earliest known examples of a fully domesticated sunflower north of Mexico have been found in Tennessee
Tennessee
Tennessee is a U.S. state located in the Southeastern United States. It has a population of 6,346,105, making it the nation's 17th-largest state by population, and covers , making it the 36th-largest by total land area...

, and date to around 2300 BC. Many indigenous American peoples
Indigenous peoples of the Americas
The indigenous peoples of the Americas are the pre-Columbian inhabitants of North and South America, their descendants and other ethnic groups who are identified with those peoples. Indigenous peoples are known in Canada as Aboriginal peoples, and in the United States as Native Americans...

 used the sunflower as the symbol of their solar deity
Solar deity
A solar deity is a sky deity who represents the Sun, or an aspect of it, usually by its perceived power and strength. Solar deities and sun worship can be found throughout most of recorded history in various forms...

, including the Aztecs
Tonatiuh
In Aztec mythology, Tonatiuh was the sun god. The Aztec people considered him the leader of Tollan, heaven. He was also known as the fifth sun, because the Aztecs believed that he was the sun that took over when the fourth sun was expelled from the sky...

 and the Otomi
Otomi people
The Otomi people . Smaller Otomi populations exist in the states of Puebla, Mexico, Tlaxcala, Michoacán and Guanajuato. The Otomi language belonging to the Oto-Pamean branch of the Oto-Manguean language family is spoken in many different varieties some of which are not mutually intelligible.One of...

 of Mexico and the Incas in South America
South America
South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...

. Francisco Pizarro
Francisco Pizarro
Francisco Pizarro González, Marquess was a Spanish conquistador, conqueror of the Incan Empire, and founder of Lima, the modern-day capital of the Republic of Peru.-Early life:...

 was the first European to encounter the sunflower in Tahuantinsuyo, Peru
Peru
Peru , officially the Republic of Peru , is a country in western South America. It is bordered on the north by Ecuador and Colombia, on the east by Brazil, on the southeast by Bolivia, on the south by Chile, and on the west by the Pacific Ocean....

. Gold
Gold
Gold is a chemical element with the symbol Au and an atomic number of 79. Gold is a dense, soft, shiny, malleable and ductile metal. Pure gold has a bright yellow color and luster traditionally considered attractive, which it maintains without oxidizing in air or water. Chemically, gold is a...

 images of the flower, as well as seed
Seed
A seed is a small embryonic plant enclosed in a covering called the seed coat, usually with some stored food. It is the product of the ripened ovule of gymnosperm and angiosperm plants which occurs after fertilization and some growth within the mother plant...

s, were taken back to Spain
Spain
Spain , officially the Kingdom of Spain languages]] under the European Charter for Regional or Minority Languages. In each of these, Spain's official name is as follows:;;;;;;), is a country and member state of the European Union located in southwestern Europe on the Iberian Peninsula...

 early in the 16th century. Some researchers argue that the Spaniards tried to suppress cultivation of the sunflower because of its association with solar religion and warfare.

During the 18th century, the use of sunflower oil
Sunflower oil
Sunflower oil is the non-volatile oil expressed from sunflower seeds. Sunflower oil is commonly used in food as a frying oil, and in cosmetic formulations as an emollient. Sunflower oil was first industrially produced in 1835 in the Russian Empire.- Composition :Sunflower oil is mainly a...

 became very popular in Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...

, particularly with members of the Russian Orthodox Church
Russian Orthodox Church
The Russian Orthodox Church or, alternatively, the Moscow Patriarchate The ROC is often said to be the largest of the Eastern Orthodox churches in the world; including all the autocephalous churches under its umbrella, its adherents number over 150 million worldwide—about half of the 300 million...

, because sunflower oil was one of the few oils that was not prohibited during Lent
Great Lent
Great Lent, or the Great Fast, is the most important fasting season in the church year in Eastern Christianity, which prepares Christians for the greatest feast of the church year, Pascha . In many ways Great Lent is similar to Lent in Western Christianity...

, according to some fasting traditions.

Cultivation and uses


To grow best, sunflowers need full sun. They grow best in fertile, moist, well-drained
Drainage
Drainage is the natural or artificial removal of surface and sub-surface water from an area. Many agricultural soils need drainage to improve production or to manage water supplies.-Early history:...

 soil
Soil
Soil is a natural body consisting of layers of mineral constituents of variable thicknesses, which differ from the parent materials in their morphological, physical, chemical, and mineralogical characteristics...

 with heavy mulch
Mulch
In agriculture and gardening, is a protective cover placed over the soil to retain moisture, reduce erosion, provide nutrients, and suppress weed growth and seed germination. Mulching in gardens and landscaping mimics the leaf cover that is found on forest floors....

. In commercial planting, seeds are planted 45 cm (1.5 ft) apart and 2.5 cm (1 in) deep.
Sunflower "whole seed" (fruit) are sold as a snack food, raw or after roasting in oven
Oven
An oven is a thermally insulated chamber used for the heating, baking or drying of a substance. It is most commonly used for cooking. Kilns, and furnaces are special-purpose ovens...

s, with or without salt
Salt
In chemistry, salts are ionic compounds that result from the neutralization reaction of an acid and a base. They are composed of cations and anions so that the product is electrically neutral...

 and/or seasonings added. Sunflowers can be processed into a peanut butter
Peanut butter
Peanut butter is a food paste made primarily from ground dry roasted peanuts, popular in North America, Netherlands, United Kingdom, and parts of Asia, particularly the Philippines and Indonesia. It is mainly used as a sandwich spread, sometimes in combination as in the peanut butter and jelly...

 alternative, sunflower butter. In Germany
Germany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...

, it is mixed with rye
Rye
Rye is a grass grown extensively as a grain and as a forage crop. It is a member of the wheat tribe and is closely related to barley and wheat. Rye grain is used for flour, rye bread, rye beer, some whiskeys, some vodkas, and animal fodder...

 flour
Flour
Flour is a powder which is made by grinding cereal grains, other seeds or roots . It is the main ingredient of bread, which is a staple food for many cultures, making the availability of adequate supplies of flour a major economic and political issue at various times throughout history...

 to make Sonnenblumenkernbrot (literally: sunflower whole seed bread
Bread
Bread is a staple food prepared by cooking a dough of flour and water and often additional ingredients. Doughs are usually baked, but in some cuisines breads are steamed , fried , or baked on an unoiled frying pan . It may be leavened or unleavened...

), which is quite popular in German-speaking Europe
German-speaking Europe
The German language is spoken in a number of countries and territories in West, Central and Eastern Europe...

. It is also sold as food for bird
Bird
Birds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...

s and can be used directly in cooking and salads. American Indians had multiple uses for sunflowers in the past,such as in bread, medical ointments, dyes and body paints.

Sunflower oil
Sunflower oil
Sunflower oil is the non-volatile oil expressed from sunflower seeds. Sunflower oil is commonly used in food as a frying oil, and in cosmetic formulations as an emollient. Sunflower oil was first industrially produced in 1835 in the Russian Empire.- Composition :Sunflower oil is mainly a...

, extracted from the seeds
Sunflower seed
The sunflower seed is the fruit of the sunflower . The term "sunflower seed" is actually a misnomer when applied to the seed in its pericarp . Botanically speaking, it is more properly referred to as an achene. When dehulled, the edible remainder is called the sunflower kernel.There are three types...

, is used for cooking
Cooking oil
Cooking oil is purified fat of plant origin, which is usually liquid at room temperature ....

, as a carrier oil
Carrier oil
Carrier oil, also known as base oil or vegetable oil, is used to dilute essential oils and absolutes before they are applied to the skin in massage and aromatherapy. They are so named because they carry the essential oil onto the skin. Carrier oils do not contain a concentrated aroma, unlike...

 and to produce margarine
Margarine
Margarine , as a generic term, can indicate any of a wide range of butter substitutes, typically composed of vegetable oils. In many parts of the world, the market share of margarine and spreads has overtaken that of butter...

 and biodiesel
Biodiesel
Biodiesel refers to a vegetable oil- or animal fat-based diesel fuel consisting of long-chain alkyl esters. Biodiesel is typically made by chemically reacting lipids with an alcohol....

, as it is cheaper than olive oil
Olive oil
Olive oil is an oil obtained from the olive , a traditional tree crop of the Mediterranean Basin. It is commonly used in cooking, cosmetics, pharmaceuticals, and soaps and as a fuel for traditional oil lamps...

. 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
Olive oil
Olive oil is an oil obtained from the olive , a traditional tree crop of the Mediterranean Basin. It is commonly used in cooking, cosmetics, pharmaceuticals, and soaps and as a fuel for traditional oil lamps...

.
The cake remaining after the seeds have been processed for oil is used as a livestock
Livestock
Livestock refers to one or more domesticated animals raised in an agricultural setting to produce commodities such as food, fiber and labor. The term "livestock" as used in this article does not include poultry or farmed fish; however the inclusion of these, especially poultry, within the meaning...

 feed. Some recently developed cultivar
Cultivar
A cultivar'Cultivar has two meanings as explained under Formal definition. When used in reference to a taxon, the word does not apply to an individual plant but to all those plants sharing the unique characteristics that define the cultivar. is a plant or group of plants selected for desirable...

s have drooping heads. These cultivars are less attractive to gardeners
Gardening
Gardening is the practice of growing and cultivating plants. Ornamental plants are normally grown for their flowers, foliage, or overall appearance; useful plants are grown for consumption , for their dyes, or for medicinal or cosmetic use...

 growing the flowers as ornamental plant
Ornamental plant
Ornamental plants are plants that are grown for decorative purposes in gardens and landscape design projects, as house plants, for cut flowers and specimen display...

s, but appeal to farmer
Farmer
A farmer is a person engaged in agriculture, who raises living organisms for food or raw materials, generally including livestock husbandry and growing crops, such as produce and grain...

s, because they reduce bird
Bird
Birds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...

 damage and losses from some plant diseases
Phytopathology
Plant pathology is the scientific study of plant diseases caused by pathogens and environmental conditions . Organisms that cause infectious disease include fungi, oomycetes, bacteria, viruses, viroids, virus-like organisms, phytoplasmas, protozoa, nematodes and parasitic plants...

. Sunflowers also produce latex
Latex
Latex is the stable dispersion of polymer microparticles in an aqueous medium. Latexes may be natural or synthetic.Latex as found in nature is a milky fluid found in 10% of all flowering plants . It is a complex emulsion consisting of proteins, alkaloids, starches, sugars, oils, tannins, resins,...

, and are the subject of experiments to improve their suitability as an alternative crop for producing hypoallergenic
Hypoallergenic
Hypoallergenic, meaning "below normal" or "slightly" allergenic, was a term first used in a cosmetics campaign in 1953. It is used to describe items that cause or are claimed to cause fewer allergic reactions...

 rubber
Rubber
Natural rubber, also called India rubber or caoutchouc, is an elastomer that was originally derived from latex, a milky colloid produced by some plants. The plants would be ‘tapped’, that is, an incision made into the bark of the tree and the sticky, milk colored latex sap collected and refined...

.

Traditionally, several Native American groups planted sunflowers on the north edges of their gardens as a "fourth sister" to the better known three sisters
Three Sisters (agriculture)
The Three Sisters are the three main agricultural crops of various Native American groups in North America: squash, maize, and climbing beans ....

 combination of corn
Maize
Maize known in many English-speaking countries as corn or mielie/mealie, is a grain domesticated by indigenous peoples in Mesoamerica in prehistoric times. The leafy stalk produces ears which contain seeds called kernels. Though technically a grain, maize kernels are used in cooking as a vegetable...

, beans, and squash. Annual species are often planted for their allelopathic
Allelopathy
Allelopathy is a biological phenomenon by which an organism produces one or more biochemicals that influence the growth, survival, and reproduction of other organisms. These biochemicals are known as allelochemicals and can have beneficial or detrimental effects on the target organisms...

 properties.

However, for commercial farmers growing commodity crops, the sunflower, like any other unwanted plant, is often considered a weed
Weed
A weed in a general sense is a plant that is considered by the user of the term to be a nuisance, and normally applied to unwanted plants in human-controlled settings, especially farm fields and gardens, but also lawns, parks, woods, and other areas. More specifically, the term is often used to...

. Especially in the midwestern US, wild (perennial) species are often found in corn and soybean fields and can have a negative impact on yields.

Sunflowers can be used to extract toxic ingredients from soil, such as lead
Lead
Lead is a main-group element in the carbon group with the symbol Pb and atomic number 82. Lead is a soft, malleable poor metal. It is also counted as one of the heavy metals. Metallic lead has a bluish-white color after being freshly cut, but it soon tarnishes to a dull grayish color when exposed...

, arsenic
Arsenic
Arsenic is a chemical element with the symbol As, atomic number 33 and relative atomic mass 74.92. Arsenic occurs in many minerals, usually in conjunction with sulfur and metals, and also as a pure elemental crystal. It was first documented by Albertus Magnus in 1250.Arsenic is a metalloid...

 and uranium
Uranium
Uranium is a silvery-white metallic chemical element in the actinide series of the periodic table, with atomic number 92. It is assigned the chemical symbol U. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons...

. They were used to remove cesium-137
Caesium
Caesium or cesium is the chemical element with the symbol Cs and atomic number 55. It is a soft, silvery-gold alkali metal with a melting point of 28 °C , which makes it one of only five elemental metals that are liquid at room temperature...

 and strontium-90
Strontium
Strontium is a chemical element with the symbol Sr and the atomic number 38. An alkaline earth metal, strontium is a soft silver-white or yellowish metallic element that is highly reactive chemically. The metal turns yellow when exposed to air. It occurs naturally in the minerals celestine and...

 from a nearby pond after the Chernobyl disaster
Chernobyl disaster
The Chernobyl disaster was a nuclear accident that occurred on 26 April 1986 at the Chernobyl Nuclear Power Plant in Ukraine , which was under the direct jurisdiction of the central authorities in Moscow...

, and a similar campaign was mounted in response to the Fukushima Daiichi nuclear disaster
Fukushima Daiichi nuclear disaster
The is a series of equipment failures, nuclear meltdowns, and releases of radioactive materials at the Fukushima I Nuclear Power Plant, following the Tōhoku earthquake and tsunami on 11 March 2011. The plant comprises six separate boiling water reactors originally designed by General Electric ,...

. (see phytoremediation
Phytoremediation
Phytoremediation Phytoremediation Phytoremediation (from the Ancient Greek , and Latin (restoring balance or remediation) describes the treatment of environmental problems (bioremediation) through the use of plants that mitigate the environmental problem without the need to excavate the...

)

Sunflower genome


The sunflower, Helianthus annuus, genome
Genome
In modern molecular biology and genetics, the genome is the entirety of an organism's hereditary information. It is encoded either in DNA or, for many types of virus, in RNA. The genome includes both the genes and the non-coding sequences of the DNA/RNA....

 is diploid with a base chromosome
Chromosome
A chromosome is an organized structure of DNA and protein found in cells. It is a single piece of coiled DNA containing many genes, regulatory elements and other nucleotide sequences. Chromosomes also contain DNA-bound proteins, which serve to package the DNA and control its functions.Chromosomes...

 number of 17 and an estimated genome size of 2871–3189 Mbp. Some sources claim its true size is around 3.5 billion base pairs (slightly larger than the human genome
Human genome
The human genome is the genome of Homo sapiens, which is stored on 23 chromosome pairs plus the small mitochondrial DNA. 22 of the 23 chromosomes are autosomal chromosome pairs, while the remaining pair is sex-determining...

).

Mathematical model of floret arrangement



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
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
Golden ratio
In mathematics and the arts, two quantities are in the golden ratio if the ratio of the sum of the quantities to the larger quantity is equal to the ratio of the larger quantity to the smaller one. The golden ratio is an irrational mathematical constant, approximately 1.61803398874989...

 (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 graphics representations of sunflowers.

In culture

  • The sunflower is the state flower of the US state of Kansas
    Kansas
    Kansas is a US state located in the Midwestern United States. It is named after the Kansas River which flows through it, which in turn was named after the Kansa Native American tribe, which inhabited the area. The tribe's name is often said to mean "people of the wind" or "people of the south...

    , and one of the city flowers of Kitakyūshū, Japan
    Japan
    Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...

    .
  • The sunflower is often used as a symbol of green ideology, much as the red rose
    Rose
    A rose is a woody perennial of the genus Rosa, within the family Rosaceae. There are over 100 species. They form a group of erect shrubs, and climbing or trailing plants, with stems that are often armed with sharp prickles. Flowers are large and showy, in colours ranging from white through yellows...

     is a symbol of socialism
    Socialism
    Socialism is an economic system characterized by social ownership of the means of production and cooperative management of the economy; or a political philosophy advocating such a system. "Social ownership" may refer to any one of, or a combination of, the following: cooperative enterprises,...

     or social democracy
    Social democracy
    Social democracy is a political ideology of the center-left on the political spectrum. Social democracy is officially a form of evolutionary reformist socialism. It supports class collaboration as the course to achieve socialism...

    . The sunflower is also the symbol of the Vegan Society
    Vegan Society
    The Vegan Society is a registered charity and the oldest vegan society in the world, founded on November 1, 1944, in England by Donald Watson, Elsie "Sally" Shrigley, and 23 others....

    .
  • During the late 19th century, the flower was used as the symbol of the Aesthetic Movement.
  • Subject of Van Gogh's most famous still life
    Still life
    A still life is a work of art depicting mostly inanimate subject matter, typically commonplace objects which may be either natural or man-made...

    , Sunflowers
    Sunflowers (series of paintings)
    Sunflowers are the subject of two series of still life paintings by the Dutch painter Vincent van Gogh. The earlier series executed in Paris in 1887 gives the flowers lying on the ground, while the second set executed a year later in Arles shows bouquets of sunflowers in a vase...

  • The sunflower is the national flower of Peru
    Peru
    Peru , officially the Republic of Peru , is a country in western South America. It is bordered on the north by Ecuador and Colombia, on the east by Brazil, on the southeast by Bolivia, on the south by Chile, and on the west by the Pacific Ocean....

    , Russia
    Russia
    Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...

    , and Ukraine
    Ukraine
    Ukraine is a country in Eastern Europe. It has an area of 603,628 km², making it the second largest contiguous country on the European continent, after Russia...

    .
  • The sunflower was chosen as the symbol of the Spiritualist Church
    Spiritualism
    Spiritualism is a belief system or religion, postulating the belief that spirits of the dead residing in the spirit world have both the ability and the inclination to communicate with the living...

     for many reasons, but mostly because it turns toward the sun as "Spiritualism turns toward the light of truth". Modern Spiritualists often have art or jewelry with sunflower designs.
  • Starting from February 2010, Kuban Airlines
    Kuban Airlines
    Kuban Airlines is an airline based in Krasnodar, Russia. It operates domestic schedules within Russia and international charters. Its main base is Krasnodar International Airport. Its name comes from Kuban Province in southern Russia....

     of Russia
    Russia
    Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...

     painted part of its fleet in a new livery
    Livery
    A livery is a uniform, insignia or symbol adorning, in a non-military context, a person, an object or a vehicle that denotes a relationship between the wearer of the livery and an individual or corporate body. Often, elements of the heraldry relating to the individual or corporate body feature in...

     featuring enormous sunflowers.

International Sunflower Guerrilla Gardening Day


International Sunflower Guerrilla Gardening Day is 1 May. It is a day when guerrilla gardeners
Guerrilla gardening
Guerrilla gardening is gardening on another person's land without permission. It encompasses a very diverse range of people and motivations, from the enthusiastic gardener who spills over their legal boundaries to the highly political gardener who seeks to provoke change through direct action. It...

 around the world plant sunflowers in their neighborhoods, typically in neglected public places such as tree pits, shabby flower beds and bare roadside verges. It has taken place since 2007, and was conceived by guerrilla gardeners in Brussels, (who go by the name of The Brussels Farmers). They declared it Journée Internationale de la Guérilla Tournesol. It has been championed by guerrilla gardeners around the world, notably by GuerrillaGardening.org and participation has grown each year since then. In 2010, more than 5000 people signed up for the event from North America, Europe and Asia. Although sunflower sowing at this time of the year is limited to relatively temperate parts of the Northern Hemisphere, this day is also marked in other parts of the world by planting appropriate to the season.

Varieties



The following are varieties of sunflowers (in alphabetical order):
  • 'American Giant Hybrid'
  • 'Arnika'
  • 'Autumn Beauty' (Autumnal colors)
  • 'Aztec Sun'
  • 'Black Oil'
  • 'Dwarf Sunspot'
  • 'Evening Sun'
  • 'Giant Primrose'
  • 'Indian Blanket Hybrid'
  • 'Irish Eyes'
  • 'Italian White'
  • 'Kong Hybrid'
  • 'Large Grey Stripe'
  • 'Lemon Queen' (Pale lemon)
  • 'Mammoth Russian'
  • 'Mongolian Giant'
  • 'Orange Sun'
  • 'Peach Passion'
  • 'Peredovik'
  • 'Red Sun'
  • 'Ring of Fire'
  • 'Rostov'
  • 'Skyscraper'
  • 'Soraya'
  • 'Strawberry Blonde'
  • 'Sunny Hybrid'
  • 'Taiyo' (Orange-yellow, chocolate center)
  • 'Tarahumara'
  • 'Teddy Bear'
  • 'Titan'
  • 'Valentine'
  • 'Velvet Queen' (red to dark claret, chocolate center)
  • 'Yellow Empress'

  • Other species


    There are many species in the sunflower genus Helianthus, and many species in other genera that may be called sunflowers.
    • The Maximillian sunflower (Helianthus maximillianii) is one of 38 species of perennial sunflower
      Perennial sunflower
      Perennial sunflower is a new crop being developed by crossing wild perennial and domestic annual sunflower species.Annual sunflower is a major oilseed crop. Genes from wild perennial relatives may increase root depth and mass and extend the growing season...

       native to North America
      North America
      North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...

      . The Land Institute
      Land Institute
      The Land Institute is a non-profit research, education, and policy organization dedicated to sustainable agriculture based in Salina, Kansas, United States....

       and other breeding programs are currently exploring the potential for these as a perennial seed crop.
    • The sunchoke http://homecooking.about.com/od/foodhistory/a/sunchokehistory.htm (Jerusalem artichoke
      Jerusalem artichoke
      The Jerusalem artichoke , also called the sunroot, sunchoke, earth apple or topinambour, is a species of sunflower native to eastern North America, and found from Eastern Canada and Maine west to North Dakota, and south to northern Florida and Texas...

       or Helianthus tuberosus) is related to the sunflower, another example of perennial sunflower
      Perennial sunflower
      Perennial sunflower is a new crop being developed by crossing wild perennial and domestic annual sunflower species.Annual sunflower is a major oilseed crop. Genes from wild perennial relatives may increase root depth and mass and extend the growing season...

      .
    • The Mexican sunflower is Tithonia
      Tithonia
      Tithonia is a genus of flowering plants in the family Asteraceae. It includes 11 species, with a center of distribution in Mexico but with one species extending into the Southwestern United States and several extending into Central America. Two species, T. diversifolia and T...

       rotundifolia
      . It is only very distantly related to North American sunflowers.
    • False sunflower refers to plants of the genus Heliopsis
      Heliopsis
      Heliopsis from Greek helios for "sun" and opsis for "appearance" is a genus of herbaceous flowering plants in the daisy family Asteraceae native to North and South America.- Species :Heliopsis species include:*Heliopsis buphthalmoides...

      .

    See also


    • Carnitine
      Carnitine
      Carnitine is a quaternary ammonium compound biosynthesized from the amino acids lysine and methionine. In living cells, it is required for the transport of fatty acids from the cytosol into the mitochondria during the breakdown of lipids for the generation of metabolic energy. It is widely...

    • List of sunflower diseases
    • Sheller
    • Sunflower oil
      Sunflower oil
      Sunflower oil is the non-volatile oil expressed from sunflower seeds. Sunflower oil is commonly used in food as a frying oil, and in cosmetic formulations as an emollient. Sunflower oil was first industrially produced in 1835 in the Russian Empire.- Composition :Sunflower oil is mainly a...



    External links