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Weed Seed: Anthemis cotula (Mayweed)



Common Name



Secondary Noxious, Class 3 in the Canadian Weed Seeds Order, 2016 under the Seeds Act.


Canadian: Occurs across Canada except in NT and NU, although reports from SK and PE are questionable (Brouillet et al. 2016Footnote 1).

Worldwide: Native to the Mediterranean region and widely introduced elsewhere including South Africa, Australia, New Zealand, parts of Europe, and North and South America (CABI 2016Footnote 2, USDA-ARS 2016Footnote 3). It is found throughout the United States, including Alaska and Hawaii (Kartesz 2011Footnote 4, USDA-NRCS 2016Footnote 5).

Duration of life cycle


Seed or fruit type


Identification features



Surface Texture


Habitat and Crop Association

Cultivated fields, pastures, gardens, lawns, railway lines, roadsides and disturbed areas (FNA 1993+Footnote 6, Darbyshire 2003Footnote 7, CABI 2016Footnote 2). Found in most annual and many perennial crops, and most abundant in cereals and legumes (CABI 2016Footnote 2). Particularly adapted to rich, wet soils and may be problematic in conservation tillage systems (CABI 2016Footnote 2).

General Information

Mayweed seeds are most commonly spread by agricultural practices, and early infestations in cereal crops were thought to be largely via contaminated seed. Seeds may also be spread on agricultural equipment, and in hay, bedding, and animal manure.

Other accidental introductions are attributed to ship's ballast, and in some areas mayweed may have been introduced for medicinal or ornamental purposes. Individual plants may produce anywhere from 550-27,000 seeds depending on environmental conditions, and seed may remain viable for up to 25 years (CABI 2016Footnote 2).

Similar species

Corn chamomile (Anthemis arvensis)


Mayweed (Anthemis cotula) achenes
Mayweed (Anthemis cotula) achene
Mayweed (Anthemis cotula) achene surface

Similar species

Similar species: Corn chamomile (Anthemis arvensis) achenes
Similar species: Corn chamomile (Anthemis arvensis) achene
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