Russian Knapweed
Acroptilon repens
Description
A perennial that forms dense colonies with stems that are erect and branched. Leaves are silvery-green; the lower leaves are divided and the upper leaves are narrow and elliptical. Flowers are pink to purple and bloom from summer to fall. Flower bracts are pearly and papery with no noticeable fringes or spines.Habitat
Occurs in most soil types, especially in semi-arid habitats; common in disturbed areas such as roadsides, riverbanks, pastures, and croplandDistribution
Throughout eastern halves of Washington and Oregon, throughout IdahoImpacts
Overruns native grasslands and cultivated fields, toxic to horsesDispersal Methods
As contaminant in hay and seed lots, human activityPrevention
Look for Russian knapweed in disturbed areas, such as roadsides, riverbanks, irrigation ditches, pastures, and cropland. Areas should be monitored three times a year (spring, summer, and fall), and all of the plants should be destroyed immediately.Listings
ODA's B ListFactsheets
Photos
Distribution Map
Distribution in Washington
Distribution in Idaho
Identification Help
Other Links
Managing Russian Knapweed - University of Nevada
Element Stewardship Abstract from The Nature Conservancy's Global Invasive Species Initiative
Integrated Vegetation Management of Knapweeds