corncockle

from The Collaborative International Dictionary of English v.0.48

corncockle \corncockle\ n.
   a European annual ({Agrostemma githago}) having large
   trumpet-shaped reddish-purple flowers and poisonous seed; a
   common weed in grainfields and beside roadways; naturalized
   in America.

   Syn: corn cockle, corn-cockle, corn campion,
        crown-of-the-field, {Agrostemma githago}.
        [WordNet 1.5]