Regional Noxious. Perennial.
Russian knapweed has upright, branched stems which are covered
with soft grey hairs when young. It has flowers with tubular, spikey,
pink or purple petals and very noticeable pale green, egg-shaped bracts
beneath. Leaves are oblong, becoming smaller at the top of the plant.
Mature plants are 45 -100 cm tall.
Russian knapweed reduces the yield and quality of cereal crops
and is toxic to horses. Plant extracts have been shown to inhibit the
growth of other plants. Once established, Russian knapweed extends
in all directions and can cover an area of 3.6 m2 within two years.
Russian knapweed occurs in southern British Columbia east of the
Coast-Cascade Mountains in low- to mid-elevation grasslands, forests,
pastures, cropland, and riverbanks. It is present in the Kootenay, Okanagan,
Thompson, and Peace areas and is a major problem in the Okanagan agricultural
Russian knapweed's well-developed root system functions as the
major means of propagation and spread.