Russian Knapweed

Russian Knapweed, Hardheads

Acroptilon repens (L.) DC. (formerly Centaurea repens)

Asteraceae (Sunflower Family)

▲ ▼ young shoots emerging from creeping roots

▲ ▼ young shoots emerging from creeping roots in spring

▲ ▼ extensive creeping root system producing new off-shoots

▲ leaves of new shoots have teeth pointed toward leaf tips

▲ ▼ dense colony of Russian Knapweed in Colorado

▲ flowering stem, showing unlobed leaves in upper stem portions

▲ flower heads showing papery-tipped bracts on base of inflorescence

▲ post-flowering plant near Prescott, AZ

▲ illustration of dark, scaly roots

Acroptilon repens (L.) DC., Russian Knapweed: (Bayer Code: CENRI; US Code ACRE3)

  • Creeping perennial with creeping roots that can form dense colonies
  • Usually shorter than spotted knapweed
  • Flowers pinkish-purple, similar to spotted knapweed
  • Leaves not deeply divided--just somewhat lobed or toothed
  • Bracts under inflorescence are papery
  • Also found in western plains & west of Rocky Mountains

(Updated January 19, 2019)

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