bitter-bark

from The Century Dictionary.

• noun An Australianeuphorbiaceoustree, Petalostigma quadriloculare, the bark of which contains a powerful bitter principle which is used medicinally. Also called emu-apple, crab-tree, and native quince.
• noun Either one of two trees of the dogbane family, Tabernæmontana orientalis and Pala constricta (Alstonia constricta of F. von Müller), the barks of which are also used in medicine. The latter is better known as fever-bark. See also Alstonia bark, under bark.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun ornamental shrub or small tree of swampy areas in southwestern United States having large pink or white sepals and yielding Georgia bark for treating fever