The Collaborative International Dictionary of English v.0.48:

Dieffenbachia \Dieffenbachia\ n.
   a genus of evergreen perennial herbs of tropical America with
   lush foliage and poisonous sap; often cultivated as
   houseplants.

   Syn: genus Dieffenbachia.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

Dieffenbachia
    n 1: evergreen perennial herbs of tropical America with lush
         foliage and poisonous sap; often cultivated as houseplants
         [syn: Dieffenbachia, genus Dieffenbachia]