The mysterious lianas of the rain forest could hold the cures to myriad diseases

Snaking and twisting toward the light, as thick as a man's arm, the vines of the jungle climb from the dark forest floor up into the canopy a hundred feet overhead and weave the crowns of trees together. Think Tarzan and his monkey friends, swinging through the rain forest on a network of meandering vines, more accurately known as lianas.

Lianas contribute as much as 30 percent to the rain-forest medicine chest. Substances from these plants that have crossed into the industrialized world include tubocurarine, an important muscle relaxant; rotenone, a biodegradable pesticide; and yagé, a powerful hallucinogen now being tested for the treatment of addiction.

Although they are used by native people for everything from dandruff to athlete's foot and ailments of all the body parts in between, lianas have largely been ignored by Western science because they are maddeningly difficult to identify. Mark Plotkin's mentor, Richard Evans Schultes, spent seven years searching for a flowering specimen of the liana that makes yagé. Plotkin himself would long ago have abandoned the rigorous study of lianas were it not for his encounter with a tall, black botanist with the unlikely name of Frits van Troon.

Van Troon, born more than 60 years ago in the jungles of Suriname (then Dutch Guiana), possesses an almost magical ability to differentiate one liana from another. Van Troon's ancestors escaped from the brutal slave plantations of the colonial era and established African cultures deep in the Amazon. For them, the forest is sacred, the source of all life and healing. Van Troon's botanical genius is, in a way, the flower of his traditions, enabling him to see and understand thousands of species of the twirling, looping, and incredibly useful vines of the forest. Together, he, Plotkin, and fellow botanists Marc van Roosmalen and Bruce Hoffman are working on a book about lianas. And the secrets contained in these vines may indeed prove invaluable to Western medicine.

—A.W.