Source : Webster's Revised Unabridged Dictionary (1913)

Rhus \Rhus\, n. [L., sumac, fr. Gr. ???.] (Bot.)
   A genus of shrubs and small treets. See {Sumac}.

Source : WordNet®

Rhus
     n : deciduous or evergreen shrubs and shrubby trees of temperate
         and subtropical North America, South Africa, eastern Asia
         and northeastern Australia; usually limited to
         nonpoisonous sumacs (see genus Toxicodendron) [syn: {genus
         Rhus}]