Source : Webster's Revised Unabridged Dictionary (1913)

Conium \Co*ni"um\ (? or ?), n. [NL., fr. Gr. ? hemlock.]
   1. (Bot.) A genus of biennial, poisonous, white-flowered,
      umbelliferous plants, bearing ribbed fruit (``seeds'') and
      decompound leaves.

Source : WordNet®

Conium
     n : small genus of highly toxic biennials: hemlock [syn: {genus
         Conium}]