Bitterwood, a name given to certain species of Xylopia, a genus of Anonaceæ, trees and shrubs remarkable for the bitterness of their wood, particularly the West Indian X. glabra. Furniture made of this wood is safe from the attacks of insects.—The fruit of some of the species, particularly X. sericea, is highly aromatic and pungent like pepper. X. sericea is a large tree, a native of Brazil; its bast tissue is used for making cordage, which is excellent.
Bitterwood is also the name of Pierena excelsa (formerly Quassia excelsa), a tree of the natural order Simarubaceæ (q.v.), a native of Jamaica, the wood of which is now alone used in medicine, as Quassia (q.v.), owing to the scarcity of the Quassia amara, to which the name was first given. It is, botanically, very nearly allied to the true quassia, and possesses very similar properties, containing the crystallisable bitter principle called Quassite or Quassin. The wood, which is intensely bitter, is a very useful stomachic and tonic; an infusion of it is a well-known and useful fly-poison; and it appears to act as a powerful narcotic on many quadrupeds.