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Spotted knapweed

Spotted knapweed

Spotted knapweed

(Centauria maculosa)

Priority: -  Contain

Tags: Agricultural

Overview

Identification

Heavily branched plants from 1-1.5 meters in height. Has a single main-stem that divides into bushy, spreading branches on a mature plant. (Think of a 'tumbleweed').

Leaves are deeply lobed, hairy, grayish-green leaves. Form rosettes in their first year.

Small white, pink or purple flowers atop spiny bracts

Reproduction

Spotted knapweed is a biennial plant that reproduces by seed.

Habitat & Ecology

Found on dry roadsides, gravel pits, disturbed sites, and in fields

Impacts

Displaces native and agricultural plants, reduces forage quality and quantity for livestock, contaminates crops, and creates a fire hazard.

Management

Hand-pulling can be effective to eradicate new, small patches. Several herbicides are effective on seedlings, rosettes and mature plants. Several biocontrol agents have been released in the Mainland/Coast Region for this species, which are monitored by the Ministry of Forests and Range.