Quassia
Quassia, a bitter-tasting drug. It is used to treat indigestion and to rid the body of threadworms. Hop growers use quassia to kill plant lice. Quassia is obtained from two related trees—Surinam quassia and bitterwood, or bitter ash. Chips or shavings of the wood are soaked in water to obtain the drug. The Surinam quassia is native to Panama and the northern part of South America. It reaches a height of about 12 feet (4 m). The wood is valued for cabinet-making. The bitterwood of the West Indies reaches 50 to 60 feet (15 to 18 m).
Surinam quassia is Quassia amara; bitterwood, Picrasma excelsa. Both belong to the quassia family, Simarubaceae.