The Collaborative International Dictionary of English v.0.48:

Dendranthema \Dendranthema\ n.
   a genus comprising plants often included in the genus
   Chrysanthemum.

   Syn: genus Dendranthema.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

Dendranthema
    n 1: comprises plants often included in the genus Chrysanthemum
         [syn: Dendranthema, genus Dendranthema]