Weed Seed: Thlaspi arvense (Stinkweed)

Family

Brassicaceae

Common Name

Stinkweed

Regulation

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

Distribution

Canadian: Occurs throughout Canada (Brouillet et al. 2016^Footnote 1). Most abundant as a weed in the prairie provinces (Warwick et al. 2002^Footnote 2).

Worldwide: Native to Europe and Asia and introduced in North America, southern South America, northern Africa, South Africa, Australia, New Zealand, and beyond its native range in northern Europe (USDA-ARS 2016^Footnote 3). Widespread in temperate regions of the northern hemisphere and recently spread to temperate regions of the southern hemisphere (Warwick et al. 2002^Footnote 2).

Duration of Life Cycle

Annual or Winter Annual

Seed or Fruit Type

Seed

Identification Features

Size

• Seed length: 1.9 - 2.7 mm
• Seed width: 1.0 - 2.0 mm
• Seed thickness: 0.5 - 1.0 mm

Shape

• Seed oval shape tapering to hilum end; compressed

Surface Texture

• Distinctive pattern of concentric ridges on seed

Colour

• Reddish-brown in immature seeds, dark brown when mature

Other Features

• Hilum at narrow end, looks like an open mouth with tissue inside

Habitat and Crop Association

Cultivated fields, old fields, gardens, pastures, rangelands, meadows, thickets, woods, irrigated areas, sloughs, beaches, roadsides, lawns, railway lines and disturbed areas (FNA 1993+^Footnote 4, Warwick et al. 2002^Footnote 2, Darbyshire 2003^Footnote 5). A serious weed of pastures and cereal, oilseed, forage and vegetable crops (Warwick et al. 2002^Footnote 2, CABI 2016^Footnote 6).

General Information

Stinkweed was first introduced into Michigan in 1701 (Royer and Dickinson 1999^Footnote 7) and is now found in all U.S. states except for Hawaii (NatureServe 2015^Footnote 8). One plant is capable of producing up to 20,000 seeds, which can remain viable for 20 to 30 years (CABI 2016^Footnote 6).

Not only does stinkweed reduce crop yields, it also decreases crop quality by increasing the erucic acid content of the oil produced (Warwick et al. 2002^Footnote 2). Stinkweed can be toxic to cattle, causing symptoms such as abortion, colic, and sometimes death (Warwick et al. 2002^Footnote 2).

Similar Species

Garlic mustard (Alliaria petiolata)

• Garlic mustard seeds are a similar size, dark brown colour and have a concentric ridge surface pattern like stinkweed.
• Stinkweed seeds are oval and compressed while garlic mustards seeds are elongate and compressed only at the hilum end.

Photos

Similar species