What does "cassia" mean?

Cassia: The bark of several species of Cinnamommum 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. 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. 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.