Plants exhibit allelopathic effects and are aggressively competitive, facilitating rapid colonization and development of dense stands .
Infestations can be extremely long-lived due to extensive root and rhizome systems.
Stems dieback after flowering in summer, and new shoots are generated in spring. Introduced from Central Asia. Under most circumstances livestock will avoid grazing Russian knapweed because of its bitter taste. Cotyledons ovate to spatulate and scurfy on the lower surface. First several rosette leaves elliptic to oblanceolate and covered with a white, powdery bloom.