calumba \calum"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.
   1913 webster

   american calumba, the frasera carolinensis, also called
      american gentian. its root has been used in medicine as
      bitter tonic in place of calumba.
      1913 webster
see also:
jateorrhiza calumba cocculus palmatus colombo columbo calombo american calumba 
frasera carolinensis american gentian