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Native to North America, Helianthus annuus, better known as sunflower, is both beautiful and useful. It is widely cultivated for its edible seeds and oil and, to a lesser extent, as an ornamental. Nutritionally, the seeds contain up to 46% of polyunsaturated oil with a high percentage of linoleic acid and up to 20% protein of a high biological value. Sunflower belongs in the daisy family, Compositae (Asteraceae), and is characterised by having a flower head (capitulum) with outer yellow ray florets, which serve to attract pollinators, and inner brownish disc florets which are fertile and are arranged in spiral whorls from the centre of the head. Sunflower is pollinated by bees and some farmers place bee colonies in sunflower fields which produce honey as a by-product.

[UPB]

The Useful Plants of Boyacá project

Ecology
Alt. 2630 - 2630 m.
Distribution
Cultivated in Colombia.
Morphology General Habit
Herb.

[FTEA]

Compositae, H. Beentje, C. Jeffrey & D.J.N. Hind. Flora of Tropical East Africa. 2005

Morphology General Habit
These escapes are small annual herbs, 20–120 cm high.
Morphology Leaves
Leaves alternate, ovate, to 8 x 3.5 cm and scabridulous to the touch, petiolate.
Morphology Reproductive morphology Inflorescences Capitulum
Capitula terminal and solitary; ray florets ± 14, yellow, 35 x 10 mm; disc florets very many, yellow orange.
Note
In cultivation the plant and all its parts may become much larger. Both the cited specimens came from road-sides. Sunflower, originally from America, is cultivated in many places in East Africa for its seeds, as an oil crop. Occasionally it seems to escape and become naturalised, as in T 6, Uzaramo District:Dar es Salaam on airport road, Apr. 1977, Wingfield 3392a! and T 8, Songea District:Mkaku River SW of Kitai, Mar. 1956, Milne-Redhead & Taylor 9075!.
Figures
Fig. 143 (page 707).

[CPLC]

Bernal, R., Gradstein, S.R. & Celis, M. (eds.). 2015. Catálogo de plantas y líquenes de Colombia. Instituto de Ciencias Naturales, Universidad Nacional de Colombia, Bogotá. http://catalogoplantasdecolombia.unal.edu.co

Distribution
Cultivada en Colombia; Alt. 2630 - 2630 m.; Andes.
Morphology General Habit
Hierba

[KSP]

Kew Species Profiles

General Description

Native to North America, Helianthus annuus, better known as sunflower, is both beautiful and useful. It is widely cultivated for its edible seeds and oil and, to a lesser extent, as an ornamental. Nutritionally, the seeds contain up to 46% of polyunsaturated oil with a high percentage of linoleic acid and up to 20% protein of a high biological value. Sunflower belongs in the daisy family, Compositae (Asteraceae), and is characterised by having a flower head (capitulum) with outer yellow ray florets, which serve to attract pollinators, and inner brownish disc florets which are fertile and are arranged in spiral whorls from the centre of the head. Sunflower is pollinated by bees and some farmers place bee colonies in sunflower fields which produce honey as a by-product.

It is a common misconception that sunflower heads are heliotropic and track the sun across the sky. The alignment of sunflowers in a field is due to heliotropism at an earlier stage of their development, while the flower heads are still in bud. The buds follow the sun until the end of the bud stage when they finally position themselves facing east. This behaviour makes blooming sunflowers growing in the open like living compasses with north to the left, west behind and south to the right. 

Species Profile
Geography and distribution

Sunflower was first domesticated from its wild ancestor more than 5,000 years ago in the south-western part of the USA and, within a short period of time, became widespread throughout the Americas. Its value as an ornamental plant and use as a source of food and oil attracted the attention of European explorers who brought the crop to Europe in the 16th century.

By the 19th century sunflower was being cultivated on a wide scale in Russia, the Ukraine and Caucasus regions for the manufacture of edible vegetable oil. The crop is still important in that part of the world today along with the US and Argentina. Other key producers are India, China, Turkey, the European Union (eg France, Spain) and South Africa. Occasionally, sunflower escapes cultivation and becomes naturalized.

Habitat

Cultivated in relatively cool temperate to warm subtropical climates. Sunflowers can also be grown in the drier tropical regions but are unsuitable for humid environments. They can grow in a wide range of soils from sandy to clayey provided they are deep, free-draining and not acidic. 

Description

Overview: Helianthus annuus is an annual herb which grows up to 5 metres tall with a well-developed taproot extending up to 3 metres into the soil. The stem is erect with a slight-to-severe curve below the flower head in mature plants. In many wild types it is branched whereas in cultivated varieties the stem is unbranched.

Leaves: The leaves are positioned opposite each other in the lower part of the plant and higher up the stem they are arranged spirally. Each leaf is hairy, 10-30 × 5-20 cm with toothed margins, and is supported by a long petiole. 

Flowers: The inflorescence is a terminal head (capitulum), 10-50 cm in diameter and is surrounded by three rows of bracts (phyllaries). The flower head is comprised of outer yellow ray florets, which serve to attract pollinators, and inner brownish disc florets which are fertile. The inner florets are numerous and are arranged in spiral whorls from the centre of the head. Each floret is about 2 cm long and consists of a 5-lobed, brown or purplish corolla tube and two deciduous bristly scales (pappus), 5 stamens united into a tube and an ovary which is positioned below the flower tube and stamens. The stigma has two curved lobes and there are nectaries at the base of the style. 

Fruit: The fruit (known botanically as an achene) is up to 15-25 mm in size and can be white, brown, black or striped.

Uses

Sunflower is mainly cultivated for its tasty seeds and versatile oil and to a lesser extent for ornamental purposes.

The seeds yield edible oil, which is excellent quality due to a high proportion of unsaturated fatty acids, near absence of toxic substances, light colour and good flavour. The oil is used for salads, cooking and as an ingredient in the manufacture of margarine. The oil also has some industrial uses as drying oils for paints and varnishes and in the manufacture of soaps and cosmetics as well as a biofuel.

The by-product of sunflower oil extraction is a high protein meal, which is commonly blended with soyabean meal and used as livestock feed.

Sunflower meal is sometimes used as a substitute for wheat flour in the baking of bread and cakes for human consumption. The indigenous people of North America have a long tradition of using ground sunflower seeds to make bread-like products.

The varieties cultivated for their seeds are much larger than the oil-cultivars and are often black and white striped, are can be eaten directly. In countries like Russia, the sunflower seeds are salted and roasted whole and enjoyed as a delicious savoury snack. 

The smaller seeds are widely used in birdseed and in pet food. Some people air-dry the fruiting capitula and hang them upside down or simply leave the fruiting capitula on the plants for bird feed. Sunflower is sometimes cultivated as a forage crop.

Crop wild relatives of sunflower

The Millennium Seed Bank and the Global Crop Diversity Trust are engaged in a ten-year project, called 'Adapting Agriculture to Climate Change'. The project aims to protect, collect and prepare the wild relatives of 29 key food crops, including sunflower, so that they are available to pre-breeders for the development of new varieties that are more resilient to the effects of climate change.

Millennium Seed Bank: Seed storage

The Millennium Seed Bank Partnership aims to save plants worldwide, focusing on those plants which are under threat and those which are of most use in the future. Once seeds have been collected they are dried, packaged and stored at -20°C in our seed bank vault.

Description of seeds: Average 1,000 seed weight = 42 g

Number of seed collections stored in the Millennium Seed Bank: One

Seed storage behaviour: Orthodox. (The seeds of this plant can be dried to low moisture contents without significantly reducing their viability. This means they are suitable for long-term frozen storage such as at the MSB)

Germination testing: Successful

Helianthus annuus is one of the species included in the 'Difficult Seeds' project because many of its seeds are short-lived and may not survive a long time in storage. 

This species at Kew

Pressed and dried specimens of sunflower are held in Kew's Herbarium, where they are available to researchers by appointment. Details and images of some of these specimens can be seen online in Kew's Herbarium Catalogue.

Distribution
USA
Ecology
Cultivated in relatively cool temperate to warm subtropical climates. More information below.
Conservation
Widespread in cultivation, rarely naturalizing.

[FSOM]

M. Thulin et al. Flora of Somalia, Vol. 1-4 [updated 2008] https://plants.jstor.org/collection/FLOS

Morphology General Habit
Annual herb, up to 3 m tall or more; stems hairy
Morphology Leaves
Leaves alternate in upper part of stem, petiolate; blade narrowly to broadly ovate, up to at least 30 x 20 cm, usually serrate, hirsute
Morphology Reproductive morphology Inflorescences
Capitulum large, up to at least 20 cm in diam., nodding
Morphology Reproductive morphology Inflorescences Bracts Phyllaries
Phyllaries narrowly to broadly ovate, long-acuminate at the tip, usually hirsute and ciliate
Morphology Reproductive morphology Flowers Florets
Ray florets yellow, usually 3 cm or more long
Morphology Reproductive morphology Fruits
Achenes c. 5 mm or more long.
Distribution
Grown as an ornamental at least in N1 (Hargeysa). Native from North America; widely cultivated.
Vernacular
Common sunflower (English)
Note
First record for Somalia.

[UPB]
Use Gene Sources
Crop wild relatives which may possess beneficial traits of value in breeding programmes (State of the World's Plants 2016).
Use Materials Other Materials
Seeds - The seeds are used to make small carved animal figures (Linares et al. 2008).
Use Materials Unspecified Materials Chemicals
Materials (State of the World's Plants 2016).
Use Medicines Unspecified Medicinal Disorders
Medicinal (Instituto Humboldt 2014).

[KSP]
Use
Oil, food, livestock feed, biofuel.

[FSOM]
Use
Widely grown for its oil-rich fruits or as an ornamental.

Native to:

Arizona, Bangladesh, California, Mexico Central, Mexico Northeast, Mexico Northwest, Mexico Southwest, Nevada

Introduced into:

Alabama, Alaska, Albania, Alberta, Altay, Amur, Argentina Northeast, Argentina Northwest, Argentina South, Arkansas, Assam, Austria, Baltic States, Belarus, Belgium, Belize, Bolivia, Botswana, British Columbia, Bulgaria, Buryatiya, Cape Provinces, Caprivi Strip, Central European Rus, Chile Central, Chile North, Chile South, China North-Central, China South-Central, China Southeast, Chita, Colombia, Colorado, Connecticut, Corse, Costa Rica, Delaware, Denmark, District of Columbia, Dominican Republic, East European Russia, East Himalaya, El Salvador, Finland, Florida, France, Free State, Georgia, Germany, Great Britain, Greece, Guatemala, Hainan, Haiti, Honduras, Hungary, Idaho, Illinois, India, Indiana, Iowa, Ireland, Irkutsk, Italy, Japan, Kamchatka, Kansas, Kazakhstan, Kentucky, Khabarovsk, Kirgizstan, Korea, Krasnoyarsk, KwaZulu-Natal, Lesotho, Libya, Louisiana, Magadan, Maine, Manchuria, Manitoba, Maryland, Massachusetts, Mexico Gulf, Mexico Southeast, Michigan, Minnesota, Mississippi, Missouri, Montana, Morocco, Namibia, Nebraska, Nepal, Netherlands, New Brunswick, New Hampshire, New Jersey, New Mexico, New South Wales, New York, New Zealand North, New Zealand South, Newfoundland, North Carolina, North Caucasus, North Dakota, North European Russi, Northern Provinces, Northern Territory, Northwest Territorie, Norway, Nova Scotia, Nunavut, Ohio, Oklahoma, Ontario, Oregon, Palestine, Paraguay, Pennsylvania, Peru, Poland, Primorye, Prince Edward I., Qinghai, Queensland, Québec, Rhode I., Romania, Sakhalin, Sardegna, Saskatchewan, Sicilia, South Australia, South Carolina, South Dakota, South European Russi, Spain, Swaziland, Sweden, Switzerland, Tadzhikistan, Tasmania, Tennessee, Texas, Thailand, Tibet, Transcaucasus, Turkey, Turkey-in-Europe, Turkmenistan, Tuva, Ukraine, Uruguay, Utah, Uzbekistan, Vermont, Victoria, Virginia, Washington, West Himalaya, West Siberia, West Virginia, Western Australia, Wisconsin, Wyoming, Xinjiang, Yakutskiya, Yugoslavia

English
Sunflower
Spanish
Girasol.

Helianthus annuus L. appears in other Kew resources:

Date Reference Identified As Barcode Type Status
Jan 1, 1993 Barros, C.S.S. [141], Alagoas K000054458
Harrison, S.G., USA 40698.000
Lindheimer, F. [259], Texas K001092049 Unknown type material
Lindheimer, F. [259], Texas K001092050 Unknown type material
Lindheimer, F. [s.n.], Texas K001092051 Unknown type material
s.coll. [Cat. no. 3192] K001118761
Hoehne, W. [s.n.], Brazil K001031315
Hoehne, W. [s.n.], Brazil K001031314
s.coll. [Cat. no. 3192] K001118762
Lindheimer, F. [259], Texas K001092052 Unknown type material
Lindheimer, F. [259], Texas K001092048 Unknown type material

First published in Sp. Pl.: 904 (1753)

Accepted by

  • Dufour-Dror, J.M. & Fragman-Sapir, O. in Dufour-Dror, J.M. (2019). Alien Plant Species in Natural & Disturbed Areas in Israel Alien Invasive Plants in Israel, ed. 2: 1-246. Dan Perry Pub., Nature & Parks Authority, Israel Ministry of Environmental Protection.
  • Flora of North America Editorial Committee in Flora of North America Editorial Committee (2006). Asteraceae Flora of North America North of Mexico 21: 1-616. Oxford University Press, New York, Oxford.
  • GCC in GCC (2011). Global Compositae Checklist Global Compositae Checklist http://compositae.landcareresearch.co.nz/.
  • Koyama, H., Bunwong, S., Pornpongrungrueng, P. & Hind, D.J.N. (2016). Flora of Thailand 13(2): 143-428. The Forest Herbarium, Royal Forest Department.
  • Liogier, A.H. (1996). Flora de la Española 8: 1-588. Instituto Tecnológico de Santo Domingo.
  • Sarder, N.U. & Hassan, M.A. (eds.) (2018). Vascular flora of Chittagong and the Chittagong Hill Tracts 3: 1-978. Bangladesh National Herbarium, Dhaka.
  • Wu, Z. & Raven, P.H. (eds.) (2011). Asteraceae Flora of China 20-21: 1-992. Science Press (Beijing) & Missouri Botanical Garden Press (St. Louis).

Literature

Kew Species Profiles

  • Beentje, H. (2010). The Kew Plant Glossary: an Illustrated Dictionary of Plant Terms. Royal Botanic Gardens, Kew.
  • Mabberley, D.J. (2008). Mabberley’s Plant-book: a Portable Dictionary of Plants, their Classification and Uses. Third edition. Cambridge University Press, Cambridge.
  • Polikarpov, G.G. (1978). Sunflower’s blooming floscule is a compass. Nature 272: 122
  • Royal Botanic Gardens, Kew (2008). Seed Information Database (SID). Version 7.1.

Useful Plants of Boyacá Project

  • Crop wild relative Inventory https://www.cwrdiversity.org/checklist/ in The State of the World’s Plants Report–2016. (2016). Royal Botanic Gardens, Kew https://stateoftheworldsplants.org/2016/
  • Instituto de Investigación de Recursos Biológicos Alexander von Humbodlt (2014). Plantas alimenticias y medicinales nativas de Colombia. 2567 registros, aportados por: Castellanos, C. (Contacto del recurso), Valderrama, N. (Creador del recurso, Autor), Castro, C. (Proveedor de metadatos), Bernal, Y. (Autor), García, N. (Autor). Versión 11.0. http://i2d.humboldt.org.co/ceiba/resource.do?r=ls_colombia_magnoliophyta_2014
  • Linares, E. (1994). Inventario preliminar de las plantas utilizadas para elaborar artesanías en Colombia. Vniversitas Scientarium. Vol 2: 1-38

Kew Backbone Distributions

  • Dufour-Dror, J.M. & Fragman-Sapir, O. in Dufour-Dror, J.M. (2019). Alien Plant Species in Natural & Disturbed Areas in Israel Alien Invasive Plants in Israel, ed. 2: 1-246. Dan Perry Pub., Nature & Parks Authority, Israel Ministry of Environmental Protection.
  • Flora of North America Editorial Committee in Flora of North America Editorial Committee (2006). Asteraceae Flora of North America North of Mexico 21: 1-616. Oxford University Press, New York, Oxford.
  • GCC in GCC (2011). Global Compositae Checklist Global Compositae Checklist http://compositae.landcareresearch.co.nz/.
  • Koyama, H., Bunwong, S., Pornpongrungrueng, P. & Hind, D.J.N. (2016). Flora of Thailand 13(2): 143-428. The Forest Herbarium, Royal Forest Department.
  • Liogier, A.H. (1996). Flora de la Española 8: 1-588. Instituto Tecnológico de Santo Domingo.
  • Pruski, J.F. (ed.) (2018). Flora Mesoamericana 5(2): 1-608. Universidad Nacional Autónoma de México, México, D.F.
  • Sarder, N.U. & Hassan, M.A. (eds.) (2018). Vascular flora of Chittagong and the Chittagong Hill Tracts 3: 1-978. Bangladesh National Herbarium, Dhaka.
  • Schischkin, B.K. (ed.) (1959). Compositae. Tribes Eupatorieae, Astereae, Inuleae, Ambrosieae, Heliantheae and Heleniae Flora of the USSR 25: 1-628. Science Publishers, Inc.

Flora of Somalia

  • Flora Somalia, (2000) Author: by M. Thulin [updated by M. Thulin 2008]

Flora of Tropical East Africa

  • D.J.N. Hind in Fl. Masc. 109: 190 (1993).
  • L., Sp. Pl.: 904 (1753).
  • Maquet in Fl. Rwanda 3: 630 (1985).
  • R. O. Williams, Useful and Ornamental Plants in Zanzibar and Pemba p. 293 (1949).

Art and Illustrations in Digifolia
Digital Image © Board of Trustees, RBG Kew

Catálogo de Plantas y Líquenes de Colombia
http://creativecommons.org/licenses/by-nc-sa/3.0

Colombian resources for Plants made Accessible
http://creativecommons.org/licenses/by/3.0/

Flora of Somalia
Flora of Somalia
http://creativecommons.org/licenses/by-nc-sa/3.0

Flora of Tropical East Africa
Flora of Tropical East Africa
http://creativecommons.org/licenses/by-nc-sa/3.0

Herbarium Catalogue Specimens
Digital Image © Board of Trustees, RBG Kew http://creativecommons.org/licenses/by/3.0/

Kew Backbone Distributions
The International Plant Names Index and World Checklist of Selected Plant Families 2021. Published on the Internet at http://www.ipni.org and http://apps.kew.org/wcsp/
© Copyright 2017 World Checklist of Selected Plant Families. http://creativecommons.org/licenses/by/3.0

Kew Names and Taxonomic Backbone
The International Plant Names Index and World Checklist of Selected Plant Families 2021. Published on the Internet at http://www.ipni.org and http://apps.kew.org/wcsp/
© Copyright 2017 International Plant Names Index and World Checklist of Selected Plant Families. http://creativecommons.org/licenses/by/3.0

Kew Science Photographs
Digital Image © Board of Trustees, RBG Kew http://creativecommons.org/licenses/by/3.0/

Kew Species Profiles
Kew Species Profiles
http://creativecommons.org/licenses/by-nc-sa/3.0

Useful Plants of Boyacá Project
ColPlantA database
http://creativecommons.org/licenses/by-nc-sa/3.0
http://creativecommons.org/licenses/by/3.0/