The Collaborative International Dictionary of English v.0.48:

Dendraspis \Dendraspis\ prop. n.
   a genus of African snakes comprising the mambas.

   Syn: Dendroaspis, genus Dendroaspis, genus Dendraspis.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

Dendraspis
    n 1: mambas [syn: Dendroaspis, genus Dendroaspis,
         Dendraspis, genus Dendraspis]