The Collaborative International Dictionary of English v.0.48:

Erythroxylon \Er`y*throx"y*lon\, n. [NL., from Gr. 'eryqro`s red
   + ? wood. So named from the red wood of some species.] (Bot.)
   A genus of shrubs or small trees of the Flax family, growing
   in tropical countries. E. Coca is the source of cocaine.
   See Coca.
   [1913 Webster]

WordNet (r) 3.0 (2006):

Erythroxylon
    n 1: a large genus of South American shrubs and small trees of
         the family Erythroxylaceae [syn: Erythroxylon, genus
         Erythroxylon, Erythroxylum, genus Erythroxylum]