Fact Sheets


Sonchus arvensis L.

Family :

Famille :


Synonym(s) :

Synonyme(s) :

Common Name(s) :

Nom(s) commun(s) :

Perennial sow thistle
(English) (GC 2016)

Laiteron des champs (French) (GC 2016)

Perennial sowthistle (English) (CABI 2020)

Field sowthistle (English) (CABI 2020)

Cerraja arvense (Spanish) (CABI 2020)

  • Perennial sow thistle (Sonchus arvensis) achenes

  • Perennial sow thistle (Sonchus arvensis) achenes

  • Perennial sow thistle (Sonchus arvensis) achene

  • Perennial sow thistle (Sonchus arvensis) achene, close-up of surface

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Regulation :

Remarques Réglementation:

  • CFIA Weed Seeds Order - Class 2: Primary Noxious Weed Seeds

Regulation Notes:

Distribution :

Répartition :

Native to Europe and temperate Asia, as far as the Russian Far East. Introduced in North America, Argentina, Chile, Fiji, New Caledonia, Australia, New Zealand, Japan, Indonesia and the Philippines (USDA-ARS 2020). In the United States it occurs throughout except for a few southern states (Kartesz 2015). Occurs in all provinces and territories of Canada (Brouillet et al. 2010+).

Habitat and Crop Association :

Habitat et Cultures Associées :

Cultivated fields, pastures, meadows, lawns, gardens, fences, shores, ditches, forests, roadsides and other disturbed areas (Lemna and Messersmith 1990; Darbyshire 2003). A weed of annual crops in temperate areas, notably cereals, Zea mays (corn), oilseed crops, Beta vulgaris subsp. vulgaris (sugarbeet), Solanum tuberosum (potatoes) and vegetables (CABI 2020).

Economic Use, cultivation area, and Weed Association :

Utilisation économique, zone de culture et association de mauvaises herbes :

Duration of Life Cycle :

Durée du cycle vital:


Dispersal Unit Type :

Type d’unité de dispersion :


General Information


Sonchus arvensis was probably introduced into North America as a seed contaminant (Lemna and Messersmith 1990). A single plant may produce 3000-9750 seeds (Lemna and Messersmith 1990), which can remain viable in the soil for several years (CABI 2020).


Sonchus arvensis flower (Theodore Webster, USDA Agricultural Research Service, Bugwood.org)



  • Achene


    • Achene length*: 2.3 – 3.8 mm; width: 0.7 – 1.5 mm
    *Note: minimum and maximum of 10 achenes in a normal range of this species using image measurement (ISMA 2020)


    • Long oval, oblong or egg-shaped achene, flattened

    Surface Texture

    • Achene has a rough surface with longitudinal ribs alternating with deep grooves and transverse ridges


    • Achene is dull dark reddish brown

    Other Features


    • Pappus of fine white hairs, 8.0 – 14.0 mm long (FNA 1993+) may be present, but is generally removed during processing

    Achene end with pappus

    • A ring of white tissue surrounds a small style remnant at the end with pappus

    Achene end without pappus

    • A ring of white tissue is found at the end of the achene attached to the flower head.
  • Seed


    • Seed similar to achene size


    • Seed is oval shaped with one pointed end, flattened

    Surface Texture

    • Seed has a smooth texture


    • Seed is a shiny straw yellow colour

    Other Features

    • Seed coat is translucent
  • Embryo


    • Embryo fills the seed


    • Embryo is spatulate, axial position


    • Endosperm absent, nutritive tissue stored in the cotyledons

    Other Features

    • Cotyledons are soft-textured

Identification Tips


The achenes of S. arvensis can be distinguished from similar species by the dark brown colour, oblong shape and deep grooves between the longitudinal ribs.

Additional Botany Information



  • Florets yellow or yellow-orange and cylindrical shaped, involucral bracts glandular (FNA 1993+)

Vegetative Features

  • Plants exudes a white latex sap when broken (Lemna and Messersmith 1990)
  • Reproduces both by seeds and vegetatively through thickened roots. Roots are of 2 types: vertical rhizomes and horizontal, spreading stolons (Lemna and Messersmith 1990)

Similar Species


Similar species are based on a study of seed morphology of various species, and those with similar dispersal units are identified. The study is limited by physical specimen and literature availability at the time of examination, and possibly impacted by the subjectivity of the authors based on their knowledge and experience. Providing similar species information for seed identification is to make users aware of similarities that could possibly result in misidentification.

Sonchus oleraceus L. (annual sow thistle)

S. oleraceus achenes are a similar size (length*: 2.4 – 3.4 mm; width: 0.7 – 1.2 mm), teardrop shaped, narrower at the end opposite the pappus, a light brown colour with shallow surface wrinkling compared to S. arvensis achenes.

*Note: minimum and maximum of 10 achenes in a normal range of this species using image measurement (ISMA 2020)

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Brouillet, L., Coursol, F., Meades, S. J., Favreau, M., Anions, M., Bélisle, P. and Desmet, P. 2010+. VASCAN, the database of vascular plants of Canada. http://data.canadensys.net/vascan/ Accessed November 24,2020.

Centre for Agriculture and Bioscience International (CABI). 2020. Invasive Species Compendium, CAB International, Wallingford, UK. https://www.cabidigitallibrary.org/journal/cabicompendium Accessed November 24, 2020.

Darbyshire, S. J. 2003. Inventory of Canadian Agricultural Weeds. Agriculture and Agri-Food Canada, Research Branch. Ottawa, ON.

The Flora of North America Association (FNA). 1993+. Flora of North America North of Mexico. 19+ vols. Flora of North America Editorial Committee, eds. New York and Oxford, http://beta.floranorthamerica.org/Main_Page; http://www.fna.org/FNA/ Accessed September 1, 2020.

Flora of North America (FNA) Editorial Committee, eds. 1993+. Flora of North America North of Mexico [Online]. 22+ vols. New York and Oxford.  Accessed December 29, 2022.

Global Biodiversity Information Facility (GBIF) Secretariat. 2022. https://doi.org/10.15468/39omei Accessed via https://www.gbif.org/species/3105813 Accessed December 29, 2022.

Government of Canada (GC). 2016. Canadian Weed Seeds Order. https://laws-lois.justice.gc.ca/eng/regulations/SOR-2016-93/page-2.html (English) https://laws-lois.justice.gc.ca/fra/reglements/DORS-2016-93/page-2.html (French)

International Seed Morphology Association (ISMA). 2020. Method for Seed Size Measurement. Version 1.0. ISMA Publication Guide.  https://www.idseed.org/authors/details/method_for_seed_size_measurement.html

Kartesz, J. T. 2015. The Biota of North America Program (BONAP). North American Plant Atlas. Chapel Hill, N.C., www.bonap.org/MapSwitchboard.html Accessed November 24, 2020.

Lemna, W. K. and Messersmith, C. G. 1990. The biology of Canadian weeds. 94. Sonchus arvensis L. Canadian Journal of Plant Science 70: 509-532.

U.S. Department of Agriculture-Agricultural Research Services (USDA-ARS). 2020. Germplasm Resources Information Network (GRIN), https://npgsweb.ars-grin.gov/gringlobal/taxon/taxonomysimple.aspx Accessed November 24, 2020.



Jennifer Neudorf, Angela Salzl, Ruojing Wang, Karen Castro, Katrina Entwistle

Canadian Food Inspection Agency