Cassia

n.
  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.
  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.
    3. 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.