What does "cascarilla" mean?

Cascarilla: A euphorbiaceous West Indian shrub (Croton Eleutheria); also, its aromatic bark. Cascarilla bark (or Cascarila) (Med.), the bark of Croton Eleutheria. It has an aromatic odor and a warm, spicy, bitter taste, and when burnt emits a musky odor. It is used as a gentle tonic, and sometimes, for the sake of its fragrance, mixed with smoking tobacco, when it is said to occasion vertigo and intoxication.