Russian knapweed (Rhaponticum repens)
Description: Russian knapweed is a deep-rooted perennial that was introduced in the 1800s and is toxic to horses. It is 2'-3' in height with branched, hairy stems that are ridged, and numerous.
Life Cycle: Herbaceous perennial
Habitat: Waste places or dry-land areas.
Leaves: Hairy. Lower leaves deeply indented. Upper leaves short, narrow, and smooth edged.
Flower: White, pink, or lavender disk flowers with heads surrounded by small leafy bracts up to 0.5" in diameter.
Fruit: Gray or yellow smooth seeds.
Root: Deep and extensive rhizomes, can be allelopathic.
The problem is…Russian knapweed persists in cultivated fields when established and produces deep roots.
The scientific name has been reclassified as Rhaponticum repens.
