Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide


Helianthus annuus



Helianthus annuus (sunflower)


  • Last modified
  • 22 November 2018
  • Datasheet Type(s)
  • Invasive Species
  • Host Plant
  • Preferred Scientific Name
  • Helianthus annuus
  • Preferred Common Name
  • sunflower
  • Taxonomic Tree
  • Domain: Eukaryota
  •   Kingdom: Plantae
  •     Phylum: Spermatophyta
  •       Subphylum: Angiospermae
  •         Class: Dicotyledonae

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Helianthus annuus (sunflower); roadside habit. Bozeman, Montana, USA. September 2008.
CaptionHelianthus annuus (sunflower); roadside habit. Bozeman, Montana, USA. September 2008.
Copyright©Prof Matt Lavin-2008/Bozeman, Montana, USA - CC BY-SA 2.0
Helianthus annuus (sunflower); roadside habit. Bozeman, Montana, USA. September 2008.
HabitHelianthus annuus (sunflower); roadside habit. Bozeman, Montana, USA. September 2008.©Prof Matt Lavin-2008/Bozeman, Montana, USA - CC BY-SA 2.0
Helianthus annuus (sunflower); flower. The disk flowers are typically darker yellow compared to the ray flowers. Bozeman, Montana, USA. September 2008.
TitleFlower head
CaptionHelianthus annuus (sunflower); flower. The disk flowers are typically darker yellow compared to the ray flowers. Bozeman, Montana, USA. September 2008.
Copyright©Prof Matt Lavin-2016/Bozeman, Montana, USA - CC BY-SA 2.0
Helianthus annuus (sunflower); flower. The disk flowers are typically darker yellow compared to the ray flowers. Bozeman, Montana, USA. September 2008.
Flower headHelianthus annuus (sunflower); flower. The disk flowers are typically darker yellow compared to the ray flowers. Bozeman, Montana, USA. September 2008.©Prof Matt Lavin-2016/Bozeman, Montana, USA - CC BY-SA 2.0
Helianthus annuus (sunflower); *SEM image of sunflower pollen grains. Note scale. (*Zeiss DSM 962 SEM)
TitlePollen grains
CaptionHelianthus annuus (sunflower); *SEM image of sunflower pollen grains. Note scale. (*Zeiss DSM 962 SEM)
CopyrightPublic Domain - Released by /via wikipedia
Helianthus annuus (sunflower); *SEM image of sunflower pollen grains. Note scale. (*Zeiss DSM 962 SEM)
Pollen grainsHelianthus annuus (sunflower); *SEM image of sunflower pollen grains. Note scale. (*Zeiss DSM 962 SEM)Public Domain - Released by /via wikipedia
Helianthus annuus (sunflower); seeds.
CaptionHelianthus annuus (sunflower); seeds.
Copyright©McLeod/via wikipedia - CC BY-SA 3.0
Helianthus annuus (sunflower); seeds.
SeedsHelianthus annuus (sunflower); seeds.©McLeod/via wikipedia - CC BY-SA 3.0
Helianthus annuus (sunflower); close-up of seeds, hulled, achene (a) and dehulled (b).
CaptionHelianthus annuus (sunflower); close-up of seeds, hulled, achene (a) and dehulled (b).
CopyrightPublic Domain - Released by Ryan Kaldari (Kaldari)/via wikipedia
Helianthus annuus (sunflower); close-up of seeds, hulled, achene (a) and dehulled (b).
SeedsHelianthus annuus (sunflower); close-up of seeds, hulled, achene (a) and dehulled (b).Public Domain - Released by Ryan Kaldari (Kaldari)/via wikipedia


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Preferred Scientific Name

  • Helianthus annuus L.

Preferred Common Name

  • sunflower

International Common Names

  • English: common sunflower
  • Spanish: girasol
  • French: tournesol
  • Portuguese: girassol; mirasol

Local Common Names

  • Germany: Gemeine Sonnenblume
  • Italy: girasole
  • Netherlands: zonnebloem
  • Sweden: vanlig solros

EPPO code

  • HELAN (Helianthus annuus)

Summary of Invasiveness

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The following summary is from Witt and Luke (2017):


An annual plant [(25–) 50–300 (–450) cm tall] with erect, usually rough to hairy stems and a relatively deep taproot; this weedy variety is highly variable, hybridizing with several other cultivated forms.


Mexico and USA.

Reason for Introduction

Accidentally as a contaminant.


Roadsides, disturbed areas, wastelands, urban open spaces, fallow land and croplands.


Establishes readily in disturbed areas, displacing plants of other species.

Taxonomic Tree

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  • Domain: Eukaryota
  •     Kingdom: Plantae
  •         Phylum: Spermatophyta
  •             Subphylum: Angiospermae
  •                 Class: Dicotyledonae
  •                     Order: Asterales
  •                         Family: Asteraceae
  •                             Genus: Helianthus
  •                                 Species: Helianthus annuus


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The cultivated sunflower is an erect, hardy, often unbranched, coarse, stout-stemmed annual herb, with a varying height up to 4 m. The stem is robust, circular in section, 3-6 cm in diameter, curved below the head, and woody when mature. It is filled with white pith that often becomes hollow with age. The root is a taproot, which can penetrate the soil to a depth of about 3 m, with a large lateral spread of surface roots; however, most of the roots generally remain in the first 50 cm. 

Leaves are usually alternate (lower leaves opposite), ovate, cordate, with three main veins, 10-30 cm long, 5-20 cm wide, margin serrate, and carried on long petioles. The colour of the leaves is usually dark green. Lower leaves are larger, broadly ovate or heart-shaped, and attach individually or in pairs. The base of the leaf blade is recurved as it joins a prominent petiole. Teeth on leaf margins range from inconspicuous to clearly present. Upper leaves are smaller, broadly lance-shaped or ovate, and attach individually to the stem. 

The flowering head is heliotropic (rotating to face the sun). Flowering heads have 16-30, yellow to gold, ray flowers surrounding a large central disc, and may reach up to 3.5 cm in diameter. Tall, ornamental cultivars have more numerous smaller flowers, whereas cultivars for oil extraction are shorter and have a single flower head. Disc flowers are dark brown to purple. Involucral bracts are broadly ovate, with tips drawn out to a fine point. The disc-shaped flowering head is borne terminally on the main stem, 10-50 cm in diameter, sometimes drooping, and containing 800-8000 bisexual florets. Around the margin of the head there are individual ray flowers, which are sterile, brightly coloured, usually yellow, but varying from deep yellow to red. The brown or purplish disc florets are spirally arranged, flowering from the outer to the centre. 

The ovary is inferior with a single basal ovule. Fruits are dry, indehiscent achenes, variable in colour (white, brown, black, or often dark with white stripes). Seed is compressed, flattened oblong, the top truncated and base pointed, 10-25 mm long, 7-15 mm wide. The 1000-kernel weight varies from 50 g to many times this. 


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More than 100 species of sunflowers grow in the wild, all from the New World and most of them in North America. Helianthus annuus, the common annual sunflower, is widespread in the USA and especially abundant west of the Mississippi River. Wild sunflower seeds were an important source of food for Indians living in prehistoric times. At least one group of Indians in the Midwest of USA started to cultivate sunflowers more than 3000 years ago, the practice spreading to other Native Americans living in the Southwest and in Mexico. The sunflower has the distinction of being the only important crop plant to have been domesticated in the USA.

More than half the world's cultivated sunflowers are grown in Russia and Eastern Europe, where plant breeders in the 1930-1950s developed sunflower varieties with seeds containing nearly 50% oil and flower heads exceeding 30 cm in diameter.

Distribution Table

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The distribution in this summary table is based on all the information available. When several references are cited, they may give conflicting information on the status. Further details may be available for individual references in the Distribution Table Details section which can be selected by going to Generate Report.

Continent/Country/RegionDistributionLast ReportedOriginFirst ReportedInvasiveReferenceNotes


AfghanistanPresentFAO, 2009Sunflower seed production (2008) 16,000 MT (F)
AzerbaijanPresentFAO, 2009Sunflower seed production (2008) 16,537 MT
ChinaPresentFAO, 2009Sunflower seed production (2008) 1,850,000 MT (*)
IndiaPresentFAO, 2009Sunflower seed production (2008) 1,112,000 MT
IraqPresentFAO, 2009Sunflower seed production (2008) 19,000 MT (F)
IsraelPresentFAO, 2009Sunflower seed production (2008) 25,300 MT
JordanPresentFAO, 2009Sunflower seed production (2008) 0 MT (F)
KazakhstanPresentFAO, 2009Sunflower seed production (2008) 185,750 MT
KyrgyzstanPresentFAO, 2009Sunflower seed production (2008) 53,000 MT
LebanonPresentFAO, 2009Sunflower seed production (2008) 0 MT (F)
MyanmarPresentFAO, 2009Sunflower seed production (2008) 350,000 MT (F)
PakistanPresentFAO, 2009Sunflower seed production (2008) 603,894 MT
SyriaPresentFAO, 2009Sunflower seed production (2008) 21,643 MT (F)
TajikistanPresentFAO, 2009Sunflower seed production (2008) 3,274 MT
ThailandPresentFAO, 2009Sunflower seed production (2008) 23,764 MT
TurkeyPresentFAO, 2009Sunflower seed production (2008) 992,000 MT
UzbekistanPresentFAO, 2009Sunflower seed production (2008) 12,000 MT (*)


AlgeriaPresentFAO, 2009Sunflower seed production (2008) 50 MT (F)
AngolaPresentFAO, 2009Sunflower seed production (2008) 11,000 MT (F)
BotswanaPresentFAO, 2009Sunflower seed production (2008) 7,000 MT (F)
EgyptPresentFAO, 2009Sunflower seed production (2008) 21,483 MT
KenyaPresentIntroduced Invasive FAO, 2009; Witt and Luke, 2017
MalawiPresentIntroducedFAO, 2009; Witt and Luke, 2017Naturalized
MoroccoPresentFAO, 2009Sunflower seed production (2008) 32,310 MT
MozambiquePresentFAO, 2009Sunflower seed production (2008) 5,128 MT
NamibiaPresentFAO, 2009Sunflower seed production (2008) 50 MT (F)
South AfricaPresentFAO, 2009Sunflower seed production (2008) 885,560 MT
SudanPresentFAO, 2009Sunflower seed production (2008) 100,000 MT
TunisiaPresentFAO, 2009Sunflower seed production (2008) 10,000 MT (F)
UgandaPresentFAO, 2009Sunflower seed production (2008) 190,000 MT
ZambiaPresentFAO, 2009Sunflower seed production (2008) 8,000 MT (F)
ZimbabwePresentFAO, 2009Sunflower seed production (2008) 23,000 MT (*)

North America

CanadaPresentFAO, 2009Sunflower seed production (2008) 112,200 MT
MexicoPresentFAO, 2009Sunflower seed production (2008) 5 MT
USAPresentFAO, 2009Sunflower seed production (2008) 1,552,570 MT

South America

ArgentinaPresentFAO, 2009Sunflower seed production (2008) 4,646,065 MT
BoliviaPresentFAO, 2009Sunflower seed production (2008) 191,317 MT (F)
BrazilPresentFAO, 2009Sunflower seed production (2008) 145,659 MT
ChilePresentFAO, 2009Sunflower seed production (2008) 7,607 MT
ColombiaPresentFAO, 2009Sunflower seed production (2008) 0 MT (F)
EcuadorPresentFAO, 2009Sunflower seed production (2008) 270 MT (F)
ParaguayPresentFAO, 2009Sunflower seed production (2008) 200,000 MT (*)
UruguayPresentFAO, 2009Sunflower seed production (2008) 54,200 MT


AlbaniaPresentFAO, 2009Sunflower seed production (2008) 2,500 MT
AustriaPresentFAO, 2009Sunflower seed production (2008) 79,658 MT
BelarusPresentFAO, 2009Sunflower seed production (2008) 22,000 MT (*)
BulgariaPresentFAO, 2009Sunflower seed production (2008) 1,300,710 MT
CroatiaPresentFAO, 2009Sunflower seed production (2008) 119,900 MT
Czech RepublicPresentFAO, 2009Sunflower seed production (2008) 60,993 MT
FrancePresentFAO, 2009Sunflower seed production (2008) 1,607,977 MT
GermanyPresentFAO, 2009Sunflower seed production (2008) 48,900 MT
GreecePresentFAO, 2009Sunflower seed production (2008) 15,600 MT
HungaryPresentFAO, 2009Sunflower seed production (2008) 1,468,100 MT
ItalyPresentFAO, 2009Sunflower seed production (2008) 260,927 MT
MoldovaPresentFAO, 2009Sunflower seed production (2008) 371,935 MT
PolandPresentFAO, 2009Sunflower seed production (2008) 4,669 MT
PortugalPresentFAO, 2009Sunflower seed production (2008) 16,200 MT
RomaniaPresentFAO, 2009Sunflower seed production (2008) 1,169,940 MT
Russian FederationPresentFAO, 2009Sunflower seed production (2008) 7,350,240 MT
SerbiaPresentFAO, 2009Sunflower seed production (2008) 454,282 MT
SlovakiaPresentFAO, 2009Sunflower seed production (2008) 192,346 MT
SloveniaPresentFAO, 2009Sunflower seed production (2008) 414 MT
SpainPresentFAO, 2009Sunflower seed production (2008) 873,800 MT
SwitzerlandPresentFAO, 2009Sunflower seed production (2008) 12,300 MT
UkrainePresentFAO, 2009Sunflower seed production (2008) 6,526,000 MT


AustraliaPresentFAO, 2009Sunflower seed production (2008) 73,000 MT

Biology and Ecology

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Sunflower prefers the warm temperate regions, but is cultivated from 40°S to 55°N. Sunflower is unsuitable for humid climates. New cultivars are adapted to a wide range of environments. The plant grows well at temperatures of 20-30°C, although a range of 8–34°C is tolerated. A frost-free period of 120 days is usually necessary for commercial crops. Good yields can be obtained with 500 mm of rainfall or irrigation water. The plants are quite drought-resistant, except during the flowering period. Sunflowers grow well in any well-drained, neutral to slightly alkaline sandy soil. Seed should normally be planted 3-8 cm deep, depending on cultivar. A seedbed temperature of 25-30°C is best but should not be below 15°C. Seed rate, spacing and number of plants per hectare vary widely, depending (among other things) on seed size: for example, the number of plants per hectare varies from 28,000 to 75,000. To obtain high seed yields, application of fertilizer is necessary. It was found that 1000 kg seed removed 60 kg N, 10 kg P and 180 kg K. Sunflower seedlings are poor competitors to weeds, and young plants are easily damaged by mechanical weed control. Moreover, the period of effective machinery use is limited. Several herbicides are registered for use with sunflower. The growth cycle is usually about 4 months, but ranges from 60 to 180 days depending on the environment and genotype. 


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Sunflower oil has become the world's second most important vegetable oil and is used for cooking and to make margarine, salad dressing, lubricants, paints and soaps. Sunflower oil is considered a premium oil due to its light colour, low level of saturated fats, mild flavour, good taste and ability to be used at high cooking temperatures. Oil content of the seed varies from 25 to 65%. Oil composition depends on temperature and can be 20-60% linoleic acid and 25-65% oleic acid, protein content is 15-20%. Sunflower oil is mainly used for food purposes. Inferior grades of oil are used for the production of paint, varnish and soap. The remaining material after oil extraction has a protein content of 28-45% and is used as cattle feed.

Sunflower is sometimes grown as a silage crop as feed for livestock, when the crop has to be harvested when half of the flowering head of the plant has mature seeds. Seeds contain 20-40% protein and 40-65% oil, comprising up to 80% linoleic acid (C18:2). As well as extraction of edible oil, seeds can be eaten raw or as salted or toasted snacks, and ground into a meal for using in bread and cakes, or they can be used as birdseed. Sunflowers are also used as an industrial raw material (oil, cellulose), or for poultry and animal feeds (seeds, pressing residues, green material).

Native Americans used sunflower plants for treating a variety of ailments. Dakota Indians made a broth of sunflower heads for a drink to relieve chest pains. Pueblo Indians of the Southwest USA used plant parts to cure rattlesnake and spider bites as well as for healing cuts and other wounds. More recent folk and herbal medicine uses include the control of pain, inflammation, coughs and a host of other remedies. Hopi Indians in the USA still grow a particular variety of single-headed sunflower that is tall, slender with dark leaves, and has a thin, dark purple seed that requires a longer growing season to mature than other local varieties. This sunflower is prized for the brilliant blue, purple, black or red dye that is made from the hulls and used to dye wool, cotton and baskets, as well as for making ceremonial body paint.

Uses List

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Animal feed, fodder, forage

  • Fodder/animal feed

Human food and beverage

  • Food
  • Oil/fat
  • Seeds


  • Dye/tanning
  • Oils

Medicinal, pharmaceutical

  • Cosmetic
  • Source of medicine/pharmaceutical

Distribution Maps

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