The Collaborative International Dictionary of English v.0.48:

Cahinca root \Ca*hin"ca root`\ [Written also cainca root.]
   [See Cahincic.] (Bot.)
   The root of an American shrub (Chiococca racemosa), found
   as far north as Florida Keys, from which cahincic acid is
   obtained; also, the root of the South American Chiococca
   anguifuga, a celebrated antidote for snake poison.
   [Webster 1913 Suppl.]