Helianthus annuus

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Helianthus annuus L.

alt=Description of SunflowerSunset.jpg picture.
sunflower field at sunset
Order Asterales
Family Asteraceae
Genus Helianthus

2n = 34

Origin : United States and Mexico

wild and cultivated

English sunflower
French tournesol

Summary of uses
  • edible seed oil
  • fruit or kernels eaten as a snack
  • young flower heads can be eaten boiled like artichokes
  • many ornamental forms, with flowers of various colors
  • stalk pith is used as a lightweight insulating material


  • erect and branched herbaceous plant in the wild, single-stemmed in cultivated forms.
  • entire leaves, alternate, rough to the touch
  • radiate flower head, with numerous tubular flowers in the center and bright yellow ligulate flowers

A striking feature of sunflowers is that all flowering heads seem to point eastwards. Before flower opening, the young plant is facing the East in the early morning, and follows the sun during the day. At night, it comes back to its original position. But when flowers open, they stop eastwards.

F1 hybrids are usually grown, among which all individuals are of the same height, with a single large flower head. The presence of isolated, taller, branched individuals with small flower heads shows that the seed lot contains impurities. If these individuals are numerous, this means that the farmer used his own seeds, and that we are, thus, cultivating the heterogeneous F2 generation.

Popular names

English sunflower
French tournesol, soleil
German Sonnenblume
Dutch zonnebloem
Italian girasole
Spanish girasol ; chimalate, acahual (Mexique)
Catalan gira-sol
Portuguese girassol
Polish słonecznik
Russian подсолнечник - podsolnečnik, подсолнух - podsolnuh
  • European names are borrowed to the italian name girasole.
  • See all European names


  • subsp. lenticularis (Dougl.) Cockerell (1914) is the wild form from North western America. It has many branches with small flower heads.
  • subsp. annuus var. annuus is an adventitious form from North East America.
  • subsp. annuus var. macrocarpus (DC). Cockerell (1914) includes cultivated forms, which have only one stem and a big terminal flower head.


  • Cultivars of which seeds are eaten as snacks usually have large flower heads and big brown and white striped kernels used for their seeds eaten as snacks have usually big heads and big brown and white-striped achenes.
  • Cultivars grown for oil extraction have average flower heads and small black achenes.
    • Usual oil producing sunflower cultivars give an oil with 24% oleic acid and 65% linoleic acid.
    • High oleic cultivars give an oil with 50% to 90% oleic acid. They must be grown separated from usual cultivars (more than 500 m apart) because pollen contamination would cause a decrease of the oleic acid content.
  • Ornamental cultivars show flowers with diverse colors, or double flowers. Many cultivars are interspecific hybrids.


Domestication in North America

Sunflowers were domesticated by Native Americans in the Northeastern United States. These consumed fried or pounded seed, turning them into a paste. This paste had a cosmetic use, or was mixed with corn flour to make cakes. But they didn't extract the oil.

The plant was cultivated as isolated individuals in or near cornfields. Cultivars with tall stems and large flower heads were selected.

According to Lentz et al. (2008a), the sunflower was also domesticated independently in Mexico. This is disputed by Brown (2008) and Heiser (2008b), to whom Lentz et al. (2008b) respond. Brown points out that the Mexican names for the sunflower are all motivated, indicating a relatively recent origin. Heiser adds that there is no convincing mention of the plant in Hernández and Sahagún.

  • See Sunflowers in Buffalo Bird Woman's Garden Recounted by Maxi'diwiac (Buffalo Bird Woman) of the Hidatsa Indian Tribe (ca.1839-1932), edited by Gilbert Livingstone Wilson (1868-1930). Originally published as "Agriculture of the Hidatsa Indians: An Indian Interpretation" by Gilbert Livingstone Wilson, Ph.D. (1868-1930) Minneapolis, The University of Minnesota (Studies in the Social Sciences, #9), 1917. Ph. D. Thesis. Fascinating first hand relation.

Introduction to Europe in the 16th century

Dodoens's illustrations are from the same wood engraving. They represent a cultivated type with a single large flower head. Leaves are drawn as alternate, although they are in fact opposite decussate.

During centuries, sunflower was grown as an ornamental plant. Targioni-Tozzetti mentions it in his chapter about ornamental plants, and Candolle omits it because he did not deal with ornamentals.

Its use as chicken food may have begun then, and is still practiced up to now (as entire heads). Sunflower has been one of the most important temperate oilseeds in Europe since the 1970s. Varieties rich in oleic acid ("Oleisol") are also grown.

Adoption as an oil crop in Russia

This transition is mainly due to the Orthodox Church. The latter indeed imposed long periods of leanness, during Lent and for Christmas. A long list of prohibited oil-rich foods was compiled in the 18th century, but sunflower was not on the list because as a newcomer, it was still largely unknown. Peasants began to cultivate the plant in Ukraine and in Kuban, and the first crushing factories were established in 1830.

During the first half of the 20th century, Russian breeders improved the oil content, and chosed a type of cultivars with small stems and medium flower heads. Russian cultivars then spread to Western Europe. Hitler allegedly invaded the Soviet Union in order to gain access to sunflower oil, among other things, as Germany was in dire need of cooking oil.

Discovery of a male-sterility character in France

In the second half of the twentieth century, Europe (and France in particular) began to invest in the research of "metropolitan" oilseeds, because it could no longer count on colonial oils. In 1969, at the INRA research station in Clermont-Ferrand, the French scientist Patrice Leclercq discovered a cytoplasmic male sterility trait by hybridizing a sunflower with Helianthus petiolaris Nuttall. This event allowed an easy production of F1 hybrid seeds. This trait is now used all over the world, and global sunflower production has doubled since. Sunflowers has even come back to North America, to be cultivated as a cash crop for the first time.

Read Targioni-Tozzetti (1853), Gray & Trumbull (1883) and Sturtevant (1919) articles.


De la moelle [des tiges], plus légère que le liège, on confectionne des ceintures de sauvetage ert de natation, des bouées, parfois (en Chine) du papier, des poupées, etc. (Fournier, 1948). (From the pith [of the stems], which is lighter than cork, we make life belts and swimming, buoys, sometimes (in China) paper, dolls, etc. )

Nowadays, the pith is tested as an insulating material in construction (Magniont, 2010)


  • Anderson, E., 1956. Man as a maker of new plants and new plant communities. in W.L. Thomas (ed.), Man’s role in changing the face of the earth. Chicago. 763 p.
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  • Bonjean, Alain, 1993. Le tournesol. Paris, Editions de l’Environnement. 242 p.
  • Brown, Cecil H., 2008. A lack of linguistic evidence for domesticated sunflower in pre-Columbian Mesoamerica. Proc. Nat. Acad. Sci. USA, 105 (30) : E47. doi : 10.1073/pnas.0804505105 et PBAS. Says that Lentz's names are all motivated.
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  • Heiser, Charles B. Jr., 1998. The domesticated sunflower in Mexico ? Genetic Res. Crop Evol., 45 : 447-449.
  • Heiser, Charles B. Jr., 2008a. The sunflower (Helianthus annuus) in Mexico : further evidence for a North American domestication. Genetic Res. Crop Evol., 55(1): 9-13.
  • Heiser, Charles B. Jr., 2008b. How old is the sunflower in Mexico? Proc. Nat. Acad. Sci. USA, 105 (30) : E48. doi : 10.1073/pnas.0804588105 et PNAS.
  • Lentz, David L. ; Pohl, Mary E.D. ; Alvarado, José L. ; Tarighat, Somayeh & Bye, Robert, 2008a. Sunflower (Helianthus annuus L.) as a pre-Columbian domesticate in Mexico. Proc. Nat. Acad. Sci. USA, 105 (17) : 6232-6237. doi : 10.1073/pnas.0711760105 et PNAS.
  • Lentz, David L. ; Pohl, Mary DeLand & Bye, Robert, 2008b. Reply to Rieseberg and Burke, Heiser, Brown, and Smith: Molecular, linguistic, and archaeological evidence for domesticated sunflower in pre-Columbian Mesoamerica. Proc. Nat. Acad. Sci. USA, 105 (30) : E49-E50. doi : 10.1073/pnas.0805347105
  • Lentz David L., Pohl Mary E.D., Pope Kevin O. & Wyatt Andrew R., 2001. Prehistoric sunflower (Helianthus annuus L.) domestication in Mexico. Econ. Bot., 55(3): 370-376.
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  • Pappalardo Joe, 2008. Sunflowers: the secret history: the unauthorized biography of the world's most beloved weed. Woodstock, Overlook Press. 256 p.
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