The Collaborative International Dictionary of English v.0.48:

Polygalic \Po*lyg"a*lic\, a. (Chem.)
   Of, pertaining to, or obtained from, Polygala; specifically,
   designating an acrid glucoside (called polygalic acid,
   senegin, etc.), resembling, or possibly identical with,
   saponin.
   [1913 Webster]