Weed Seed: Sinapis arvensis (Wild mustard)



Common Name

Wild mustard


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


Canadian: Occurs throughout Canada except in NU (Brouillet et al. 2016Footnote 1).

Worldwide: Native to northern Africa, Europe and temperate Asia and introduced in North and South America, southern Africa, Japan, Australia and New Zealand (USDA-ARS 2016Footnote 2). Widespread in the United States (USDA-NRCS 2016Footnote 3).

Duration of life cycle


Seed or fruit type


Identification features


  • Seed diameter: 1.0 - 2.0 mm


  • Globose, often slightly compressed at hilum

Surface Texture

  • Seed dull surface with thin reticulations that tend to radiate from the hilum


  • Seed usually black, can also be reddish-brown, brown or greenish-brown

Other Features

  • Hilum appears as a small wart and short line of white tissue
  • A small, round dark area associated with the hilum can be seen in some light-coloured seeds

Habitat and Crop Association

Cultivated fields, fallow fields, gardens, clearings, orchards, shores, riverbanks, roadsides, railway lines and disturbed areas (Warwick et al. 2000Footnote 4, Darbyshire 2003Footnote 5). A serious weed of field crops in the Canadian prairies, especially in canola (Royer and Dickinson 1999Footnote 6, Warwick et al. 2000Footnote 4).

General Information

Wild mustard was documented in crops in New York State as early as 1748 and had reached Nova Scotia by 1829 (Mulligan and Bailey 1975Footnote 7). Individual plants are capable of producing 2,000 to 3,500 seeds and can remain viable in soil for up to 60 years (Warwick et al. 2000Footnote 4). Both the seeds and leaves of this plant contain glucosinolates that are capable of causing severe illness in livestock (Warwick et al. 2000Footnote 4).

Similar species

Argentine rapeseed (Brassica napus subsp. napus)

  • Argentine canola seeds are a similar size, globose shape, dark colour and fine reticulate surface pattern.
  • Argentine canola has a minutely stippled surface with a 'sparkling' look that wild mustard lacks.
  • Argentine canola also tends to have an angular outline and a darker D-shaped area around the hilum, while wild mustard is round and lacks a dark area around the hilum.


Wild mustard (Sinapis arvensis) seeds
Wild mustard (Sinapis arvensis) seed, hilum view
Wild mustard (Sinapis arvensis) seed
Wild mustard (Sinapis arvensis) seed
Wild mustard (Sinapis arvensis) pod

Similar species

Similar species: Argentine rapeseed (Brassica napus subsp. napus) seeds
Similar species: Argentine rapeseed (Brassica napus subsp. napus) seed, hilum view
Similar species: Argentine rapeseed (Brassica napus subsp. napus) seed
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