Prepared by Jennifer L. D’Appollonio, Assistant Scientist, University of Maine, Orono, ME 04469. Updated April 2019. Scientific name: Centaurea L. (Centaurea nigra L. / Centaurea jacea L.) Common name(s): Knapweed (lesser knapweed, black knapweed / brown knapweed, brownray knapweed) Links: C. nigra USDA PLANTS Profile, Go Botany; C. jacea USDA PLANTS Profile, Go Botany Images: