The Collaborative International Dictionary of English v.0.48:

Pistacia \Pis*ta"ci*a\, n. [NL. See Pistachio.] (Bot.)
   The name of a genus of trees, including the tree which bears
   the pistachio (Pistacia vera), the Mediterranean mastic
   tree (Pistacia Lentiscus), and the species (Pistacia
   Terebinthus) which yields Chian or Cyprus turpentine.
   [1913 Webster]

WordNet (r) 3.0 (2006):

Pistacia
    n 1: a dicotyledonous genus of trees of the family Anacardiaceae
         having drupaceous fruit [syn: Pistacia, genus Pistacia]