The Collaborative International Dictionary of English v.0.48:

Nothofagus \Nothofagus\ prop. n.
   A genus of beeches of temperate southern hemisphere except
   Africa; the southern beech.

   Syn: genus Nothofagus.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

Nothofagus
    n 1: beeches of temperate southern hemisphere except Africa:
         southern beech [syn: Nothofagus, genus Nothofagus]