Weed Seed: Daucus carota subsp. carota (Wild carrot)

Family

Apiaceae

Common Name

Wild carrot

Regulation

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

Distribution

Canadian: Occurs in BC, MB, NB, NL, NS, ON, PE, QC, SK (Brouillet et al. 2016^Footnote 1).

Worldwide: Native to Europe, northern Africa and southwestern Asia (CABI 2016^Footnote 2, USDA-ARS 2016^Footnote 3). Widely introduced elsewhere in temperate regions including China, Japan, Australasia and North America (CABI 2016^Footnote 2, USDA-ARS 2016^Footnote 3).

Duration of life cycle

Biennial

Seed or fruit type

Schizocarp, divided into 2 mericarps

Identification features

Size

• Mericarp length: 2.0 - 4.0 mm
• Mericarp width: 1.3 - 2.3 mm
• Mericarp thickness: 1.0 mm

Shape

• Oval to teardrop-shaped mericarp, flat on one side, compressed

Surface Texture

• Mericarp dull, with 5 ribs on outer side and 2 small arched ribs on inner side

Colour

• Mericarp dull grey-brown with straw yellow ribs and bristles

Other Features

• Ribs on mericarp are straight; the oil ducts between have a smooth surface
• Ribs on mericarp are usually winged with prominent hairs that may be removed during processing
• Each rib is lined with small bristles that are visible even if the seed is worn
• One end of the mericarp has a pointed remnant floral style

Habitat and Crop Association

Waste places, roadsides and disturbed areas, old fields, meadows and underused or depleted pastures (Dale 1974^Footnote 4, Darbyshire 2003^Footnote 5). Not typically considered a weed of cultivated fields on prime agricultural land but increasingly found in no-till production systems (Dale 1974^Footnote 4, Cowbrough 2004^Footnote 6). Reported in corn, soybeans and winter wheat in Ontario (Cowbrough 2004^Footnote 6).

General Information

Wild carrot spread to North America through garden plantings and escaped to become a weed of roadsides and waste places (Darbyshire 2003^Footnote 5, DiTomaso and Healy 2007^Footnote 7). It may also have been introduced as a seed contaminant (CABI 2016^Footnote 2).

Wild carrot hybridizes readily with cultivated carrot (DiTomaso and Healy 2007^Footnote 7) and was first reported in Ontario and Quebec in 1883 (Royer and Dickinson 1999^Footnote 8). Seeds are spread by wind, or by attachment to animals and clothing; they may also be spread in contaminated seed or grain (Dale 1974^Footnote 4, CABI 2016^Footnote 2). Individual plants produce 1,000-40,000 seeds and seeds remain viable in the soil for several years (Dale 1974^Footnote 4).

Similar species

Poison hemlock (Conium maculatum)

• Poison hemlock has similar mericarp size, teardrop shape, dull brown-coloured fruits and distinct ribs as wild carrot.
• Poison hemlock (thickness: 1.3 - 2.0 mm) is generally thicker and lacks the rib-associated hairs of wild carrot.
• The mericarp surface of poison hemlock is wrinkled between wavy ribs, and wild carrot is smooth between straight ribs.

Photos

Similar species