knapweed

2 definitions found

knapweed - Collaborative International Dictionary of English v.0.48 :

  Knapweed \Knap"weed`\, n. (Bot.)
     The black centaury (Centaurea nigra); -- so called from the
     knoblike heads of flowers. Called also bullweed.
     [1913 Webster]

knapweed - WordNet (r) 2.1 (2005) :

  knapweed
      n 1: any of various plants of the genus Centaurea having purple
           thistlelike flowers