scientific name: Quassia amara
other common names: Quassia, Jamaica bark, bitter-wood, hombre grande
growing areas: Southern Mexico to Brazil
physical description: It is a shrub or small tree that can grow to a height of close to 20 feet.
traditional uses: The bark has been widely used as a febrifuge (fever reducer) and insecticide. The plant is so bitter—more so than quinine—that extracts of it are used commercially in the production of bitters and other flavorings. Central Americans are reported to use the wood to construct clothing storage boxes that are impervious to moths.
Among the most unusual uses attributed to amargo is to treat alcoholism by mixing an extract with sulfuric acid and other substances to produce a tonic that is said to destroy the appetite for alcohol. But for the most part, it has been used as a treatment for diarrhea, particularly in Costa Rica, where indigenous peoples are said to carry around wood shavings of amargo bark to be used as needed. Brazilians also used a decoction from the wood for treating diarrhea, dysentery, and intestinal gas. Mexicans used the bark to treat intestinal parasites and a decoction made from the roots to treat stomach upset.
availability and dosage: It can be found in powder and capsule form. Dosages vary.
contraindications: It should be avoided by menstruating women because it may cause uterine colic, according to botanist Julia F. Morton, who lists the plant in her book The Atlas of Medicinal Plants of Middle America. Some experts say it is contraindicated in pregnancy.
special precautions: Consult your physician before beginning any use of an ethnobotanical substance for medicinal purposes.
medical research: Laboratory tests with male rats indicated that the plant extracts have an antifertility effect. The tests showed that an extract from the stem wood of amargo appeared to shrink the animals' testes and related organs and significantly reduced both sperm count and testosterone levels in the blood. The researchers found that the substance quassin appeared to be responsible for these effects.