The Collaborative International Dictionary of English v.0.48:

Callitris \Callitris\ n.
   a genus of evergreen monoecious coniferous trees or shrubs;
   the cypress pines.

   Syn: genus Callitris.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

Callitris
    n 1: evergreen monoecious coniferous trees or shrubs: cypress
         pines [syn: Callitris, genus Callitris]