Fact Sheets


Anthemis cotula L.

Family :

Famille :


Synonym(s) :

Synonyme(s) :

Common Name(s) :

Nom(s) commun(s) :

(English) (GC 2016)

Camomille des chiens (French) (GC 2016)

Dog-fennel (English) (Darbyshire 2003)

Stinking mayweed (English) (Darbyshire 2003)

Stinking chamomile (English) (Darbyshire 2003)

  • Mayweed (Anthemis cotula) achenes

  • Mayweed (Anthemis cotula) achene

  • Mayweed (Anthemis cotula) achene surface

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Regulation :

Remarques Réglementation:

  • CFIA Weed Seeds Order - Class 3: Secondary Noxious Weed Seeds

Regulation Notes:

Distribution :

Répartition :

Native to the Mediterranean region and widely introduced elsewhere including South Africa, Australia, New Zealand, parts of Europe, and North and South America (CABI 2020; USDA-ARS 2020). It is found throughout the United States, including Alaska and Hawaii (Kartesz 2015; USDA-NRCS 2020). Occurs across Canada except in Northwest Territories and Nunavut (Brouillet et al. 2010+).

Habitat and Crop Association :

Habitat et Cultures Associées :

Cultivated fields, pastures, gardens, lawns, railway lines, roadsides and disturbed areas (Darbyshire 2003; CABI 2020). Found in most annual and many perennial crops, and most abundant in cereals and legumes (CABI 2020). Particularly adapted to rich, wet soils and may be problematic in conservation tillage systems (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


Anthemis cotula achenes are commonly spread by agricultural practices, and early infestations in cereal crops were thought to be largely via contaminated seed (CABI 2020). Achenes may also be spread on agricultural equipment, and in hay, bedding, and animal manure (CABI 2020). Depending on environmental conditions, individual plants may produce anywhere from 550-27,000 seeds that are capable of remaining viable for up to 25 years (CABI 2020). Other accidental introductions are attributed to ship’s ballast, and in some areas A. cotula may have been introduced for medicinal or ornamental purposes (CABI 2020).

The plant contains chemicals that are toxic to seedlings of other species (CABI 2020). This species is open pollinating, resulting in high genetic and morphological diversity (CABI 2020).


Anthemis cotula infestation (Joseph M. DiTomaso, University of California – Davis, Bugwood.org)



  • Achene


    • Achene length*: 1.3 – 2.1 mm; width: 0.6 – 0.9 mm
    *Note: minimum and maximum of 10 achenes in a normal range of this species using image measurement (ISMA 2020)


    • Achene is wedge-shaped, cylindrical in 3 dimensions

    Surface Texture

    • Achene surface ridged reticulate with longitudinal ribs
    • Surface is warty tuberculate in longitudinal rows, generally following the achene ribs


    • Achene shiny straw yellow or yellowish-brown

    Other Features


    • Absent

    Achene end often with pappus

    • A small style remnant is present at this end of the achene, may be removed during processing

    Achene end without pappus

    • A dull yellowish, thick, rounded attachment point is at this end of the achene, may be removed during processing
  • Seed


    • Seed size same as achene size


    • Seed is wedge-shaped

    Surface Texture

    • Seed is smooth (Gealey et al. 1985)


    • Seed is orange colored
  • Embryo


    • Embryo fills the seed


    • Embryo is spatulate shaped, axial position


    • Nutritive tissue stored in the cotyledons

Identification Tips


The achenes of similar Anthemis species are wedge-shaped, but A. cotula can be easily distinguished by a reticulate surface and warty tuberculate texture.

Additional Botany Information



  • Flowering heads 5.0 – 9.0 mm in diameter, dome or cone-shaped (FNA 1993+)
  • Disc florets short, yellow and ray florets are long and white coloured (FNA 1993+)

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.

Anthemis arvensis L. (corn chamomile)

A. arvensis achenes (length*: 2.0 – 3.1 mm; width: 1.1 – 2.2 mm) are generally larger than A. cotula achenes, and the surface has thick ribs without warty tubercles.

*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 October 15, 2020.

Centre for Agriculture and Bioscience International (CABI). 2020. Invasive Species Compendium, CAB International, Wallingford, UK. https://www.cabidigitallibrary.org/journal/cabicompendium Accessed November 23, 2020.

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

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

Global Biodiversity Information Facility (GBIF) Secretariat. 2022. https://doi.org/10.15468/39omei Accessed via https://www.gbif.org/species/8035698 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)

Gealy D. R., Young F. L., and Morrow L. A. 1985. Germination of mayweed (Anthemis cotula) achenes and seed. Weed Science, 33(1):69-73.

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. http://www.bonap.net/napa Accessed October 13, 2020.

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 October 13, 2020.

U.S. Department of Agriculture-Natural Resources Conservation Service (USDA-NRCS). 2020. The PLANTS Database. National Plant Data Team, Greensboro, NC USA. http://plants.usda.gov Accessed October 13, 2020.



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

Canadian Food Inspection Agency