The Collaborative International Dictionary of English v.0.48:

Saltbush \Salt"bush`\, n. (Bot.)
   An Australian plant (Atriplex nummularia) of the Goosefoot
   family.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Atriplex \Atriplex\ n.
   a genus of plants of the goosefoot family (Chenopodiaceae);
   its members include species called orach and saltbush.

   Syn: genus Atriplex.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

saltbush
    n 1: any of various shrubby plants of the genus Atriplex that
         thrive in dry alkaline soil