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Brown Knapweed

Brown knapweed
Photo credit: Alexander Mrkvicka, Botanik im Bild, Retrieved from flora.nhm-wien.ac.at

Common Name: Brown Knapweed

Scientific Name: Centaurea jacea

Habitat: grassland, grassland dry, grassland wet, forests - open areas

Provincial Designation: Prohibited Noxious

Prohibited Noxious weeds are plant species that are designated as "prohibited noxious" in the Alberta weed regulation. Prohibited noxious weeds must be destroyed, meaning all growing parts need to be killed or the plant's reproductive mechanisms need to be rendered non-viable.

Origin

Brown knapweed is native to Europe and was probably introduced to North America as an ornamental species.

Legislated Because

Brown knapweed can invade open forests, grasslands, and prairies. It can out-compete native vegetation, reducing biodiversity and available forage species.

Description

Brown knapweed flowers are 15-25 cm wide. Bracts usually have a distinctive papery margin and are light brown in colour. The leaves are green in colour, lance-shaped or shallowly lobed, and become progressively smaller up the stem. The fruits usually don't have a plume or bristles.

Brown knapweed grows up to 150 cm tall.