The Collaborative International Dictionary of English v.0.48:

Cascara buckthorn \Cas"ca*ra buck"thorn`\ (Bot.)
   The buckthorn (Rhamnus Purshiana) of the Pacific coast of
   the United States, which yields cascara sagrada.
   [Webster 1913 Suppl.]

The Collaborative International Dictionary of English v.0.48:

chittamwood \chittamwood\ n.
   1. a shrubby tree of the U. S. Pacific coast (Rhamnus
      purshianus or Rhamnus purshiana), whose bark is the
      cascara sagrada, used as a mild cathartic or laxative.

   Syn: cascara, cascara buckthorn, bearberry, bearwood,
        chittimwood, Rhamnus purshianus.
        [WordNet 1.5]

   2. a deciduous tree of SE U.S. and Mexico.

   Syn: false buckthorn, chittimwood, shittimwood, black haw,
        Bumelia lanuginosa.
        [WordNet 1.5]

   3. a shrubby tree of southern U.S. (Cotinus obovatus)
      having large plumes of feathery flowers resembling puffs
      of smoke; -- called also American smoke tree.

   Syn: American smokewood, Cotinus americanus, Cotinus
        obovatus.
        [WordNet 1.5]