Source : Webster's Revised Unabridged Dictionary (1913)

Calumba \Ca*lum"ba\, n. [from kalumb, its native name in
   Mozambique.] (Med.)
   The root of a plant ({Jateorrhiza Calumba}, and probably
   {Cocculus palmatus}), indigenous in Mozambique. It has an
   unpleasantly bitter taste, and is used as a tonic and
   antiseptic. [Written also {colombo}, {columbo}, and
   {calombo}.]

   {American calumba}, the {Frasera Carolinensis}, also called
      {American gentian}. Its root has been used in medicine as
      bitter tonic in place of calumba.

Source : WordNet®

American gentian
     n : any of various tall perennial herbs constituting the genus
         Frasera; widely distributed in warm dry upland areas of
         California, Oregon, and Washington [syn: {columbo}, {American
         columbo}, {deer's-ear}, {deer's-ears}, {pyramid plant}]