The Collaborative International Dictionary of English v.0.48:

Smilax \Smi"lax\, n. [L., bindweed, Gr. ???.] (Bot.)
   (a) A genus of perennial climbing plants, usually with a
       prickly woody stem; green brier, or cat brier. The
       rootstocks of certain species are the source of the
       medicine called sarsaparilla.
   (b) A delicate trailing plant (Myrsiphyllum asparagoides)
       much used for decoration. It is a native of the Cape of
       Good Hope.
       [1913 Webster]