An Ethnobotanical Perspective on Ayahuasca
Richard Evans Schultes, Ph.D. F.L.S. Curator of Economic Botany and Executive Director Botanical Museum of Harvard University, Cambridge, Massachusetts, U.S.A.

Family Malpighiaceae Banisteriopsis caapi (Spr. ex Briesb.)
One of the weirdest of the hallucinogens is the drink of the western Amazon known as ayahuasca, caapi, natema or yagé. Although not nearly so popularly known as peyote or, nowadays, as the sacred mushrooms, this narcotic has nonetheless had an undue share of sensational articles that have played fancifully with unfounded claims, especially with regard to its "telepathic" powers. Notwithstanding its extraordinarily bizarre psychotomimetic effects, this narcotic preparation was hidden from European eyes until just a little over a century ago. The earliest report of ayahuasca appears to have been that of Villavicencio in his geography of Ecuador, written in 1858. The source of the drug, he wrote, was a vine used by the Zaparos, Angateros, Mazanes and other tribes of the Rio Napo basin: "to foresee and to answer accurately in difficult cases, be it to reply opportunely to ambassadors from other tribes in a question of war; to decipher plans of the enemy through the medium of this magic drink and take proper steps for attack and defence; to ascertain, when a relative is sick, what sorcerer has put a curse; to carry out a friendly visit to other tribes; to welcome foreign travellers or, at last, to make sure of the love of their womenfolk".

Banisteriopsis Caapi
A few years earlier, in 1851, the British explorer Richard Spruce had discovered the Tukanoan tribes in Amazonian Brazil using a liana called caapi to induce intoxication, but his observations were not published until later. One of Spruce's greatest contributions was his precise identification of the source of caapi as a new species of the Malpighiaceae. The species was described and called Banisteria Caapi. Recent botanical studies have shown that this concept cannot be accomodated in the genus Banisteria and it has been transferred to the allied genus Banisteriopsis. The correct name now is, accordingly, Banisteriopsis Caapi.

Spruce wrote of the caapi-drinking ceremony: "I had gone with the full intention of experimenting the caapi myself, but I had scarcely dispatched one cup of the nauseous beverage, which is but half the dose, when the ruler of the feast... came up with a woman bearing a large calabash of caxiri (mandioca beer), of which I must needs take a copious draught, and as I know the mode of its preparation, it was gulped down with secret loathing. Scarcely had I accomplished this feat, when a large cigar 2 feet long and as thick as the wrist, was put lighted into my hand, and etiquette demanded that I should take a few whiffs of it - I, who had never in my life smoked a cigar or a pipe of tobacco. Above all this, I must drink a large cup of palm-wine, and it will readily be understood that the effect of such a complex dose was a strong inclination to vomit, which was only overcome by lying down in a hammock and drinking a cup of coffee... ". Two years later, Spruce met with caapi amongst the Guahibo Indians of the upper Orinoco of Colombia and Venezuela. Here the natives "not only drink an infusion but also chew the dried stem..." In the century that followed Spruce's remarkable work, many explorers, travellers, anthropologists and botanists referred to ayahuasca, caapi or yagé, usually without details and often without botanical identification beyond the statement that the drug was prepared from a forest liana.

In the years that followed the early work, the area of use of Banisteriopsis Caapi was shown to extend to the Amazon of Peru and Bolivia and even to the rain-forested Pacific coastal region of Colombia and Ecuador. Several other species of the genus with the same use were likewise reported from the western Amazon. Of outstanding interest was the work in 1922 of Rusby and White in Bolivia and the publication by Morton in 1931 of notes made by the botanical collector Guillermo Klug in the Colombian Putumayo, including the discovery of Banisteriopsis inebrians as a source of the yagé drink.

In 1957, the chemists Hochstein and Paradies analyzed "ayahuasca" from Peru, calling it Banisteriopsis Caapi, and, from the same region, yagé, which they attributed to Prestonia amazonica. They stated that the natives of the Río Napo area "commonly consume a mixed extract of the B. Caapi and P. amazonica leaves in the belief that the latter suppress the more unpleasant hallucinations associated with the pure B. Caapi extracts ". A most interesting anthropological report has recently enumerated five lianas, the barks of which are employed with Banisteriopsis Caapi by the Tukanos of the Brazilian part of the Rio Vaupes; but, unfortunately, the plants are still identified only by native names; the admixture said to fortify the drink most strongly - a vine with thickened nodes and known in Tukano as kuri-kaxpi-dí-may, I believe, possibly represent Gnetum nodosum, a very abundant element of the riverside vegetation.

Appreciable differences exist in the manner of preparing the malpighiaeceous narcotics - differences from area to area and even occasionally from tribe to tribe. In Ecuador, Colombia and Peru, near the eastern Andean slopes, the drink is made by long boiling of the ingredients; farther to the east, it is made simply by soaking and squeezing the freshly rasped bark in cold water and straining the liquid. To this day, the natives of the north-west Amazon in Brazil and Colombia use the Banisteriopsis drink for prophetic and divinatory purposes and also to fortify the bravery of male adolescents about to undergo the severely painful yurupari ceremony for initiation into manhood. The narcosis amongst these peoples, with whom I have taken caapi on many occasions, is usually pleasant, characterized by visual hallucinations in colour, which initially is very often a shade of blue or purple. In excessive doses, it is said to bring on frighteningly nightmarish visions and a feeling of extremely reckless abandon, although consciousness is not lost nor is use of the limbs unduly affected.

One encounters great difficulty in describing a Banisteriopsis intoxication for many reasons.
FIRST: the effects of harmine, the alkaloid apparently of prime psychoactive importance, is known to react variably from person to person.
SECOND: the methods of preparing ayahuasca, caapi or yagé differ from area to area.
THIRD: sundry admixtures may be employed that alter the effects of the principal ingredient of the drink.

My own experiences from participation in many Amazonian Banisteriopsis-rituals might be summarized by saying that the intoxication began with a feeling of giddiness and nervousness, soon followed by nausea, occasional vomiting and profuse perspiration. Occasionally, the vision was disturbed by flashes of light and, upon closing the eyes, a bluish haze sometimes appeared. A period of abnormal lassitude then set in during which colours increased in intensity. Sooner or later a deep sleep interrupted by dream-like sequences began. The only uncomfortable after-effect noted was intestinal upset and diarrhea on the following day. At no time was movement of the limbs adversely affected. In fact, amongst many Amazonian Indians, dancing forms part of the caapi-ritual.

Chen and Chen offered a good summary of Banisteriopsis hallucinations: "The most outstanding feature of caapi seems to be its ability to produce visual hallucinations and dreams in men. The Caucasians who took this preparation apparently confirmed the Indians' claims. Thus, Villavicencio experienced an aerial voyage, in which he saw the most beautiful sights, and Spruce quoted a Brazilian friend as saying that once, when he took a full dose of caapi, he saw all the marvels that he had read about in the Arabian Nights pass rapidly before his eyes as a panorama; the final sensations and sights were horrible, as usual. Cardenas made seven observations on men, including himself, with the decoction in various doses. All the subjects appeared to have optical illusions of different degrees. No excitement was recorded in any case."

The earliest sophisticated phytochemical work on "yagé" was apparently that of the Colombian, Fischer-Cardenas, who, in 1923, isolated alkaloidal crystals which he called telepathine, a name which an earlier Colombian, Zerda-Bayon, had coined for a presumed alkaloid as early as 1905. Fischer-Cardenas, without voucher botanical material, presumed that he was analyzing a species of Atristolochia. Further chemical and pharmacological studies were undertaken without much real progress, until Perrot and Raymond-Hamet, in 1927, first isolated an alkaloid in pure condition, conserving for it the name telepathine. A year later, Lewin investigated Banisteriopsis Caapi subsequently publishing a monograph on this "magic drug" and, what is truly remarkable, making "... a film of the action of the drug in three patients... ", undoubtedly "the first documentation of the action of monoamine-oxidase inhibitors ".

Lewin isolated an alkaloid which he called banisterine. Elger and Wolfe and Rumpf contributed by identifying the alkaloid in botanically authenticated material as harmine, known for many years and from the zygophyllaceous Peganum Harmala. Shortly thereafter, in 1939, the work of Chen and Chen confirmed the presence of harmine in stem, root and leaf material of botanically authenticated Banisteriopsis Caapi. Harmaline and tetrohydroharmine have likewise been isolated from Banisteriopsis Caapi. In 1953, botanically determined material of Banisteriopsis inebrians was analyzed with the resulting discovery of harmine in the stems, but harmaline and tetrahydroharmine were not found. All the alkaloids isolated from Banisteriopsis Caapi and B. inebrians have a beta-carboline skeleton with varying degrees of hydrogenation in the pyridine ring.

While Banisteriopsis is normally employed as a beverage, there is evidence that in the north-westernmost Amazon it may be used as snuff as well: harmine, harmaline and tetrohydroharmine have been reported from snuff powders said to have been prepared from a vine which, according to reports, was also the source of an intoxicating drink in the Rio Negro basin of Brazil. Botanically identifiable material, unfortunately, is lacking.

A recent and unusual chemical analysis carried out on stem material of the type plant of Banisteriopsis Caapi, collected by Spruce in 1852, disclosed the presence still of harmine. This material, suffering considerable damage from rot when it was abandoned in shipment in the Amazon jungle, has been stored for more than a century at Kew. Gas chromatography - mass spectrometry showed that the alkaloid content consisted exclusively of harmine. Whether the stems originally contained harmaline and tetrohydroharmine or not cannot be stated, but it is more likely that, with time, they have been transformed into the chemically more stable aromatic beta-carboline, harmine. It is truly remarkable that botanical material collected from a type plant for chemical analysis 115 years ago has finally been subjected to examination by modern analytical microtechniques.

It was Poisson who, in 1965, reported in the leaves of Banisteriopsis Rusbyana, the presence, in relatively high amounts, of N,N-dimethyltryptamine, a discovery corroborated by several later investigators. This species surprisingly did not contain the beta-carboline alkaloids. As pointed out above, this plant is one of the important admixtures with Banisteriopsis Caapi and B. inebrians in preparing the narcotic drink in the westernmost Amazon. What is even more interesting is that this is the same indole derivative found in a number of hallucinogenic snuffs used in South America.

To my knowledge, leaves of Psychotria psychotriaefolia and Banisteriopsis Rusbyana are never used alone, notwithstanding their significant content of N,N-dimethyltryptamine. Since it is suspected that this hallucinogenic compound would have little if any effect taken orally, the way in which these two plants act as admixtures with harmine-containing species is still not clear. That they do alter or even intensify the intoxication is not questioned by any field observation, and, even though most of the South American narcotic preparations containing N,N-dimethyltryptamine are taken as snuffs, the natives employ at least one other - Mimosa hostilis - in liquid form as a drink. It is obvious that there remains much field and laboratory investigation - - preferably well integrated - before we truly understand the drugs of the ayahuasca-caapi-yagé complex, notwithstanding the fact that we have had a century in which to carry out such studies. What is disconcerting, indeed, is that time may be running out for pristine investigations of this kind, as tribe after tribe becomes civilized or disappears.

Richard Evans Schultes, Ph.D. F.L.S.
"The Father of Modern Ethnobotany"
1915-2001