Cassia oil

Cassia \Cas"sia\ (k[a^]sh"[.a]), n. [L. cassia and casia, Gr.
   kassi`a and kasi`a; of Semitic origin; cf. Heb.
   qets[imac][=a]h, fr. q[=a]tsa' to cut off, to peel off.]
   1. (Bot.) A genus of leguminous plants (herbs, shrubs, or
      trees) of many species, most of which have purgative
      qualities. The leaves of several species furnish the senna
      used in medicine.
      [1913 Webster]

   2. The bark of several species of {Cinnamomum} grown in
      China, etc.; Chinese cinnamon. It is imported as {cassia},
      but commonly sold as cinnamon, from which it differs more
      or less in strength and flavor, and the amount of outer
      bark attached.
      [1913 Webster]

   Note: The medicinal "cassia" (Cassia pulp) is the laxative
         pulp of the pods of a leguminous tree ({Cassia fistula}
         or Pudding-pipe tree), native in the East Indies but
         naturalized in various tropical countries.
         [1913 Webster]

   {Cassia bark}, the bark of {Cinnamomum cassia}, etc. The
      coarser kinds are called {Cassia lignea}, and are often
      used to adulterate true cinnamon.

   {Cassia buds}, the dried flower buds of several species of
      cinnamon ({Cinnamomum cassia}, atc..).

   {Cassia oil}, oil extracted from cassia bark and cassia buds;
      -- called also {oil of cinnamon}.
      [1913 Webster]