reprinted from Witch-Doctor's Apprentice, Hunting for Medicinal Plants in the Amazon by Nicole Maxwell, Citadel Press, 1990, Chapter XXXIX, pages 376-381

     There is one plant whose properties might, I think, just possibly make it one of the most important of all the healers in the rain forest. It might meet a desperate need of present-day medicine if, as it appears, it really does fortify and return to vigorous activity a failing autoimmune system.
     I first heard of it purely by chance. The little restaurant where I often lunched was crowded, and the proprietor asked if he might give the other seat at my table to a gentleman I had never met. I said of course, and he brought over a pink-cheeked, very neat, and very polite middle-aged man. I always talk to strangers, given a chance. I've learned a lot that way. The man, Mario Arguellas, was a friendly sort of person. When I said I was there because of my interest in medicinal plants, his face lit up.
     "But that's what saved me," he said. "I was dying of cancer, and plant medicines saved me."
      We immediately were friends. Telling me all about his remarkable recovery, he mentioned having the records of his illness from the Hospital del Empleado in Lima. What luck! For once, I could get some soundly documented evidence. People are all too ready to add a little drama by insisting they were near death when they tell of curing anything more serious than a hangnail. Since he had brought up the records, I could explain that I'd studied in an American medical school and would be interested in seeing how such things were organized in Peru, and I could do it without sounding like a district attorney examining a defense witness.
      He brought me the file the following Sunday. As I read it, I could feel my eyes bugging out. This man had to be dead! Medical journals sometimes describe inexplicable cases of spontaneous remission in a cancer case that has been diagnosed as terminal. Such things do occasionally occur - nobody knows why. But a case like this?
Nine specialists had attended Mario Arguellas, and I read the analyses they'd ordered. These reported, among other things, a severe cystitis, a generalized septicemia, and ten percent of cancer cells in the bloodstream. That's a massive metastasis. Terrible!
     The tests had just been finished when, early one morning, two of the doctors came to his room and said they were sorry, but he would have to leave the hospital. Tomorrow they were all going on strike.
     The hastily summoned friends who came to take him to their home were told that it didn't really matter where he was; he was dying. If he lasted as much as ten days more, they would be very much surprised.
     Mario's friends knew a lot about plant medicine. They immediately started their own course of treatment. Among the plants they used were chanca piedra for the urinary infection - it helps with more than just kidney stones or gallstones - and a few drops of sangre de grado in a little water "to heal the blood." But the most important thing, he told me, was the plant uña de gato. They boiled twenty grams of the grated dried plant material in a liter of water, and he drank it throughout the day, every day.
      His improvement was phenomenal. "In two weeks," he told me, "I was able to leave my bed."
      The doctors' strike lasted thirty-one days. When it was over, he walked into the hospital. He enjoyed telling me about their amazement, but was a little disappointed that they hadn't thought he was a ghost.
      Before long he went back to work. Doing what, I asked, and I got another surprise: Seven hours a day he taught ballet and classical Spanish dancing, including flamenco, for the Iquitos branch of the Ministry of Culture.
     Those years of dance training I'd taken so seriously in my youth had taught me what stamina four or five hours of ballet required. But I didn't work at flamenco until much later, when I lived in Paris. I was studying with the corps de ballet of the Opéra Comique, so I was in pretty good shape when, on a trip to Barcelona, I decided to learn a little flamenco. I got a surprise. I have never known any exercise that demands such an output of energy as those prolonged zapateòs, the very fast stamping with both feet that sounds like loud castanets. That makes classical ballet feel like strolling through the park. And I was only twenty-two at that time.
     Mario Arguellas was in his middle fifties. He told me he owed his good health to not smoking, not drinking, eating sensibly, and taking a daily dose of uña de gato, which he felt sure had protected him from any recurrence of the cancer.
     I immediately started a search for the proper botanical identification. There are eight plants called uña de gato in Peru, and I wasn't able to get a specimen of whatever it was that had done the job. Mario got his supply from a man who sold it in Lima, already finely ground and packed in plastic bags. I knew only that the plant came from a place in the foothills of the jungle at an altitude of more than three thousand feet. Climate, in any country whose topography is as up-and-down as Peru's, is dominated by altitude; as a general rule, higher means colder, and different temperatures mean different species. That was a help. I began eliminating.
     I could have saved a lot of time if I'd asked Dr. McDaniel, Adriana's boss, but I didn't know then that uña de gato was among the quantities of plants he had supplied to the anticancer research program of the National Institutes of Health. McDaniel later told me that Dr. Monroe Wall, working on uña de gato, reported that they were finding some very encouraging tumor-inhibiting properties in it when the Reagan Administration came into office and canceled the research program.
     Mario's uña de gato, in some localities called garabato casha or tambor huasca, is Uncaria tomentosa (Rubiaceae). This is a woody vine which grows in the foothills, chiefly at altitudes between seven or eight hundred and twenty-five hundred meters. A very similar lowland species, known by the same set of local names, is Uncaria guianensis; it is abundant in lower altitudes of the Peruvian Amazon. It was U. tomentosa that cured Mario Arguellas, but U. guianensis that Dr. Wall studied. It appears that the two species are as nearly identical in medicinal properties as they are in appearance.
     Some time later I learned that a man whose lung cancer was cured by uña de gato had, after continuing dosage, found that he could walk normally and even climb stairs, even though for years he had been badly cripple by arthritis. Then I got good evidence of its working wonders for diabetics. Could it be that this plant might perhaps be giving a tremendous boost to the immune system? I couldn't think of any other way of examining the diversity of its effects, its ability to eliminate so many problems that, as far as my limited knowledge let me guess, appeared to have only one thing in common: they were all degenerative diseases. In any case, I had not enough knowledge to make judgments in such a serious matter. And I knew nobody in Iquitos I could get the right kind of information from, so I put the matter aside.
     Only very recently have I found any more extensive information on how some of these plants might work to benefit so many problems affecting different organs and functions. Lack of access to scientific publications is a handicap.
     News media sometimes can be a useful source of information, though I'm afraid the pronouncements of "Madame Zuzu, the Mystical Seeress, No CODs," might be about as reliable as some of the more excitable publications. But now and then I come across one that I know has substance, like the story about several species of tabebuia. These are commonly called pau d'arco and ipe in Brazil, siete cueros in Columbia, and tahuarí or sometimes palo de arco in Peru. The species most abundant around Iquitos is the yellow-flowered Tabebuia chrysantha, Bignoniaceae, thought the purple-flowered Tabenuia obscura can also be found here and there.
     A clipping someone sent me from an unidentified slick publication says research on this botanical was done at the municipal hospital in San Andre, a suburb of São Paulo, Brazil, and gives glowing accounts of its success in treating leukemia and other types of cancer with more than one species of tabebuia. The tree's ability to cure arthritis and diabetes too is mentioned without specific data.
     Any clipping is much more useful if the name and date of the publication it's cut from are given; if not, it is almost impossible to get more information from its contents.
     Around Iquitos Tabeuia chrysantha, locally called tahuarí is well known, and praised as a means of controlling diabetes. I heard that one of the most important Peruvian businessmen keeps some of it in his desk in every office he has throughout the country. From gratitude for what it has done for his diabetes, he made a vow to have it always at hand to give to anyone who needs it. But its tumor-inhibiting properties have been less known here, though some of the Linguists report its startling success as a tumor or cancer cure in some of the tribes and in the Yarinacocha villages of Tushmo, San José, and Callao.
     Peter Rachau, who has been with the Urarina tribe, has for several years been interested in native botanical medicines. He tells of the use of tahuarí also for liver and kidney disorders. And he has more accounts of uña de gato's curing tumors, which may or may not have been malignant, in members of that tribe.
     Peter attended an international congress of ethnobotanists interested in tribal medicinal plants in nearby Pucallpa a few months before I saw him in Yarinacocha. Uña de gato was one of the plants that was discussed, and several scientists gave reports of their research. Peter read me his notes.
     An Italian doctor, Giaccarino Paolo Francesco, gave a long list of ailments for which it is used, and Peter quoted him: "One mechanism of its working is that it activates T-lymphocytes and macrophages." An unnamed Spanish doctor proved that it normalizes the immunoglobulins. Macrophages gobble up harmful particles or cells, and immunoglobulins are proteins in the body's fluids that combat infections.
     Another report stated that no toxicity had been found, even with such massive doses as one gram of evaporated essence of the active principle per kilo of body weight.
     Later, when I got a very nasty infection, I decided to see what uña de gato could do to help my own immune system fight back. I had suffered the same problem some twenty-odd years earlier, and I learned then that it was the sort of localized but very stubborn infection that could only be cured by surgery, so I'd had the operation, which kept me in the hospital for a fortnight. Remembering the reports about how the plant boosted the activity