For example, some 25 percent of the medicines prescribed in the United States are based on tropical forest plants. One such medicine raised the remission rate for childhood leukemia from 20 percent in the 1960’s to 80 percent in 1985. So, according to the World Wildlife Fund, the rain forests “represent a vast pharmacy.” And countless plants are yet undiscovered, let alone examined for possible medical uses.

Consider the medicines: Alkaloids from vines are used as muscle relaxants prior to surgery; the active ingredients of hydrocortisone to fight inflammation, quinine to fight malaria, digitalis to treat heart failure, diosgenin in birth control pills, and ipecac to induce vomiting all come from rain forest plants. Other plants have shown promise in fighting AIDS and cancer, as well as diarrhea, fever, snakebite, and conjunctivitis and other eye disorders. What other cures might still lie hidden is unknown. Less than 1 percent of rain forest plant species have been examined by scientists. Lamented one botanist: “We’re destroying things we don’t even know exist.”