bullweed

from The 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]
from The Collaborative International Dictionary of English v.0.48
Bullweed \Bull"weed`\, n. [Bole a stem + weed.] (Bot.)
   Knapweed. --Prior.
   [1913 Webster]
antiflux / dictionary / bullweed
[email protected]