Smilax laurifolia

Brier \Bri"er\, Briar \Bri"ar\ (br[imac]"[~e]r), n. [OE. brere,
   brer, AS. br[=e]r, br[ae]r; cf. Ir. briar prickle, thorn,
   brier, pin, Gael. preas bush, brier, W. prys, prysg.]
   1. A plant with a slender woody stem bearing stout prickles;
      especially, species of {Rosa}, {Rubus}, and {Smilax}.
      [1913 Webster]

   2. Fig.: Anything sharp or unpleasant to the feelings.
      [1913 Webster]

            The thorns and briers of reproof.     --Cowper.
      [1913 Webster]

   {Brier root}, the root of the southern {Smilax laurifolia}
      and {Smilax Walteri}; -- used for tobacco pipes. See also
      2nd {brier}.

   {Cat brier}, {Green brier}, several species of Smilax
      ({Smilax rotundifolia}, etc.)

   {Sweet brier} ({Rosa rubiginosa}). See {Sweetbrier}.

   {Yellow brier}, the {Rosa Eglantina}.
      [1913 Webster]
    

Brier \Bri"er\, n.
   1. the white heath {Erica arborea}. --RHUD.
      [PJC]

   2. a smoking pipe made of the root of the brier[1].

   Note: Brierroot seems to have been used formerly as a term
         meaning root of the {Smilax laurifolia} and is now
         defined as root of the {Erica arborea}. Not clear when
         this changed. -- PJC.
         [PJC]