Weed Seed: Raphanus raphanistrum (Wild radish)

Family

Brassicaceae

Common Name

Wild radish

Regulation

Primary Noxious, Class 2 in the Canadian Weed Seeds Order, 2016 under the Seeds Act.

Distribution

Canadian: Occurs in all provinces but not in the territories (Darbyshire 2003Footnote 1, Brouillet et al. 2016Footnote 2).

Worldwide: Native to northern Africa, Europe and western Asia and the Caucasus. Introduced in North and South America, elsewhere in Africa and Asia, Australia and New Zealand (USDA-ARS 2016Footnote 3). It occurs throughout the United States, except for the central region (Kartesz 2011Footnote 4).

Duration of life cycle

Annual, winter annual or biennial

Seed or fruit type

Seed, often in a pod segment

Identification features

Size

  • Seed length: 2.5 - 4.5 mm
  • Seed width: 2.3 - 3.5 mm
  • Pod segment length: 4.0 - 5.5 mm
  • Pod segment width: 2.5 - 3.0 mm

Shape

  • Seed oblong to oval
  • Pod segments are cylindrical; barrel-shaped

Surface Texture

  • Seed reticulate surface with small, shallow interspaces
  • Pod segments smooth or strongly ridged

Colour

  • Seed reddish-brown with a darker area at the hilum
  • Pod segments yellow or greyish-brown

Other Features

  • Pods break up at maturity into one-seeded, cylindrical segments

Habitat and Crop Association

Cultivated fields, abandoned fields, gardens, grasslands, meadows, orchards, woods, cliffs, riverbanks, beaches, dunes, roadsides, railway lines and disturbed areas (Darbyshire 2003Footnote 1, Warwick and Francis 2005Footnote 5). In Canada, a weed of hay, cereals, corn, canola, clover, peas, lupins, potatoes, strawberries, onions, bulbs and hops (Warwick and Francis 2005Footnote 5).

General Information

Wild radish seeds may be dispersed as a contaminant of commercial cereals, as pod segments are a similar size to grains (Warwick and Francis 2005Footnote 5).

Mature seedpods usually fracture into one-seeded pod segments and approximately 10% are released as seeds (Warwick and Francis 2005Footnote 5). Seed is also dispersed by water and in the gut of many animals including birds and cattle. Seeds may remain viable in the soil for 15-20 years (CABI 2016Footnote 6).

Similar species

Radish (Raphanus sativus)

  • Radish seeds are a similar shape, colour and have similar surface reticulations as wild radish.
  • Radish seeds (length: 3.3 - 5.0 mm; width: 2.8 - 5.0 mm) are generally larger sometimes have a pointed hilum end, slightly compressed and the surface reticulations are heavier than in wild radish.

Photos

Wild radish (Raphanus raphanistrum) seeds and pods
Wild radish (Raphanus raphanistrum) seed
Wild radish (Raphanus raphanistrum) seed, hilum view
Wild radish (Raphanus raphanistrum) pod

Similar species

Similar species:Radish (Raphanus sativus) seeds
Similar species:Radish (Raphanus sativus) seed
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