Russian Knapweed

Russian knapweed (Acroptilon repens)

• Creeping, branched, deep-rooted perennial
• 18-36 inches tall
• Pinkish-purple small solitary, terminal flowers
• Upper leaves small and smooth, lower deeply lobed
• Toxic to horses
• Roots up to eight feet deep
• Black scales on roots
• Papery bracts below flowers
• Exudes allelopathic chemical, allowing it to form dense monocultures