Language selection

Search

Weed Seed: Centaurea stoebe (Spotted knapweed)

Family

Asteraceae

Synonyms

Centaurea maculosa

Common name

Spotted knapweed

Regulation

Prohibited Noxious, Class 1 in the Canadian Weed Seeds Order, 2016 under the Seeds Act. All imported and domestic seed must be free of Prohibited Noxious weed seeds.

Distribution

Canadian: Occurs in AB, BC, NB, NS, ON, QC, SK, YT (Brouillet et al. 2016Footnote 1).

Worldwide: Native to eastern Europe and western Asia. Introduced in other parts of Europe, as well as North America, Australia and New Zealand (CABI 2016Footnote 2, USDA-ARS 2016Footnote 3).

Duration of life cycle

Perennial

Seed or fruit type

Achene

Identification features

Size

Shape

Surface texture

Colour

Other features

Habitat and crop association

Rangelands, grasslands, open sites, roadsides, riverbanks and disturbed areas. Reported as a weed of alfalfa but not usually associated with crop production (CABI 2016Footnote 2).

General information

Spotted knapweed was accidentally introduced into North America in contaminated alfalfa and clover seed in the late 1800s (Ochmann 2001Footnote 4).

Spotted knapweed can thrive over a wide range of climate and soil conditions (CABI 2016Footnote 2), although it prefers well-drained, light to coarse textured soils.

Similar species

Diffuse knapweed (Centurea diffusa)

Photos

Spotted knapweed (Centurea stoebe) achene
Spotted knapweed (Centurea stoebe) achene, top-down view
Spotted knapweed (Centurea stoebe) achene, close-up
Spotted knapweed (Centurea stoebe) achenes
Spotted knapweed (Centurea stoebe) achenes

Similar species

Similar species: Diffuse knapweed (Centurea diffusa) achenes
Similar species: Diffuse knapweed (Centurea diffusa) achene
Report a problem or mistake on this page
Please select all that apply:

Thank you for your help!

You will not receive a reply. For enquiries, contact us.

Date modified: