Amazonian Medicinal Plants with Dennis McKenna

Our recent event with Dennis McKenna was due to include a short lecture on Amazonian plants but when the evening spiraled into otherworldly conversation the proposed presentation was eventually skipped.
Jack Wheeler
April 2, 2020

Dennis kindly offered to share this plant compilation with the Xapiri community so here goes... but first, a few words from Dennis to introduce this work.

The Amazon Basin is one of the most biodiverse regions on the face of the planet. It is home to more than one third of the approximately 240,000 known species of plants, more than 2.5 million insect species, over 2200 species of fish, 1300 species of birds, 427 mammals, and 380 species of reptiles. The biodiversity of plant species is reflected in the chemical diversity of the compounds found in these Amazonian species, many of which are bioactive and potentially useful to humans as medicines and nutrients. Like over 80% of the world’s peoples, the indigenous tribes of the Amazon, and increasingly the mixed mestizo populations, rely on this rich natural pharmacopoeia to meet their basic healthcare needs. Only a fraction of the world’s flora — by some estimates, less than 10% — of all plant species have ever been evaluated for potentially useful biologically active compounds. There is little doubt that there are billions, if not trillions, of dollars worth of block buster drugs that exist, ‘undiscovered’ in the Amazon rainforest. Only lack of time, funds, and willingness prevent the thorough evaluation of this chemical treasure trove. As ethnobotanist Richard Evans Schultes once observed: 'The medicines of the future will come from the forest primeval’.

Although most of these species may be unknown or ignored by science, many are known to the indigenous peoples whose habitats are located in this vast rainforest. Through trial and error, experimentation and necessity, the people of the rainforest have discovered the healing properties of many of these plants and utilize them in their own systems of traditional medicine. The greater part of this folk knowledge is not codified or written down anywhere; and as these cultures succumb to cultural decimation, as the habitats that are the home of both the peoples and the plants they utilize are degraded and destroyed, this knowledge, and the biotic resources, will be forever lost. As ethnobotanist Mark Plotkin once observed, ‘when a medicine man dies, it’s as though a library has burned down.’ Dozens of libraries are burning every day  in the Amazon and elsewhere in the world, as the people, plants, and plant knowledge of rainforest ecosystems succumb to the rapacious onslaught of ‘development.’

The plants profiled in this section represent only the tiniest fraction of the medicinal lore of indigenous Amazonian medicine people. In many cases, some of these plants have been investigated by science, but usually, the investigations are cursory and incomplete. When it comes to Amazonian species, a ‘well investigated species’ may be the subject of less than a dozen peer-reviewed publications. There  are fortunately some notable exceptions. Cat’s Claw (Uña de Gato), Uncaria species, for example, has been discussed in over 570 peer reviewed publications, most (but not all) related to their chemistry or medicinal propertiesBut even this large number is only a small fraction compared to, say, Panax ginseng, which is referenced in nearly 7000 peer reviewed publications. So the purpose of presenting this small collection is simply to highlight many of these plants. Most are widely known and used in the folk medicine of the region. Most can be purchased in the market place of any Amazonian town or village. Their uses are known and valued by the local people. Most have been barely touched by science, if they are known at all. So perhaps this small collection will be an inspiration to future generations of ethnobotanists; to seek out, collect, document, and understand these species and others. There is not much time left; both the knowledge and the plants are disappearing rapidly.

Two sources of information on Amazonian medicines have been useful to me. in my studies. One is the Amazonian Ethnobotanical Dictionary, by James Duke and Rudolfo Vasquez. Originally published in 1994 by CRC Press (ISBNk # 0-8493-3664-3), it has long been out of print, but occasionally used copies can be found in the catalogs of rare book dealers. If you run across one, buy it!

Another invaluable resource, freely available to anyone anywhere, is PubMed, the National Library of Medicine’s Biomedical database; it is the first go-to source for information on any topic in the medical and life sciences, including ethnobotany. Look there first to get a snapshot of the current state of the art on the science of any of these species. The US Government is rightly criticized for the many bad things it does, and the wasteful way it uses resources. PubMed is one of the best uses possible of tax dollars and it is a tremendous gift to the entire world. 

Dennis McKenna Ph.D.

Dennis McKenna is an ethnopharmacologist who has studied plant hallucinogens for over forty years. He is the author of many scientific papers, author and co-author of books such as; The Brotherhood of the Screaming AbyssEthnopharmacologic Search for Psychoactive Drugs, and Psilocybin: Magic Mushroom Grower's Guide. He holds a doctorate from the University of British Columbia, where his research focused on ayahuasca and oo-koo-hé, two hallucinogens used by indigenous peoples in the Northwest Amazon. 


A Small Collection of some Amazonian Medicinal plants

Lovingly compiled by Dennis McKenna
(with lots of help from the Internet and friends)


1) Common Names: Abuta; motelo sanango; Trompetero sacha

Family: Menispermaceae

Genus: Abuta

Species: grandifolia

Authority: (Mart.) Sandwith

Folk Uses: Secoction of stems & roots mixed with wild honey used for sterility in women. Root decoction for post menstrual hemmorrhages, alcoholic maceration, for rheumatism. Macerated leaves, bark, roots, mixed with rum, usd by Creoles as aphrodisiac. Wayapi use decoction of bark and stem as dental analgesic.
Root decoction used as a cardiotonic and antianemic. Antimalarial. Sionas use leaf decoction for fever. Ecuadorian Ketchwas use leaf decoc. for conjunctivitis and snakebite, root tea for difficult delivery and for nervous or weak children with colic.


2) Common Names: Bellaco caspi

Family: Apocynaceae

Genus: Himatanthus

Species: sucuuba

Authority: (Spruce) Woods

Folk Uses: Bark tea for asthma, coughs, tuberculosis.
Latex for worms; fever, rheumatism. Latex for hernia, lumbar pains, tumors; bark fro gastric ulcers. Powdered bark for recalcitrant sores. latex for botfly larvae infecttions.


3) Common Names: Sanango; lobe sanango; Toomechcoriu;

Family: Apocynaceae

Genus: Tabernaemontana

Species: sananho

Authority: R. & P.

Folk Uses: Leaves softened by fire, applied topically for rheumatic pains; used as post-partum, one week after delivery. Pulp is used as a gargle for sore throat and colds. Ticuna mix the latex with water for eye wounds. Jivaro apply the bark juice to toothache. Considered sudorific, tonic, used for colds, obesity, rheumatism, syphilis.


4) Common Names: Ajo sacha macho

Family: Bignoniaceae

Genus: Mansoa

Species: hymenaea

Authority: (D.C.) A. Gentry

Folk Uses: Alcoholic maceration of stem and roots for rheumatism; leaf infusion used in baths to treat “manchiari” a nervous state caused by terror or sudden shock, especially in children. Used in cleansing baths for bad luck. Achuales use roots as antirheumatic; Creoles use stem decoction in baths, to relieve fatique and small needle-like cramps. Palikur used to protect against bad spirits (Duke notes: shades of Dracula?). Wayapi use decoction of leaves and stems as antipyretic bath. Tapajos for body aches, flu Tocache natives use infusions for tuberculosis and rheumatism.


5) Common Names: Una de Gato; paraguayo; garabato; etc. 

Family: Rubiaceae

Genus: Uncaria

Species: tomentosa

Authority: (D.C.)

Folk Uses: Strong immune stimulant; used for cancers, inflammation, infectious diseases; rheumatism, fevers, etc.


6) Common Names: Sangre de grado; “dragon’s blood”

Family: Euphorbiaceae

Genus: Croton

Species: lechleri

Authority: Muell.Arg.

Folk Uses: Externally for wound healing, disinfectant, hemostatic; anti-inflammatory; antipruritic; internally for ulcers, diarrhoea.


7) Common Names: Chiricaspi

Family: Solanaceae

Genus: Brunfelsia

Species: grandiflora

Authority: D. Don

Folk Uses: Admixtures to Ayahuasca for special initiations; leaf decoction used internally for rheumatism, arthritis, syphilis, yellow fever, snake bite.  Strong diaphoretic and diuretic; ichthyotoxic.


8) Common Names: Ayahuasca; caapi; Yage; mariri; etc.

Family: Malpighiaceae

Genus: Banisteriopsis

Species: caapi

Authority: (Spruce ex Griseb.)

Folk Uses: Premiere psychedelic medicine of the Amazon. Basis of numerous indigenous and mestizo shamanic traditions. Used for divination, telepathy, diagnosis and cure of illnesses, and in treatment of numerous diseases of the mind/body. Beta-carboline alkaloids in Ayahuasca are potent MAO inhibitors, and render DMT (contained in other admixture plants prepared with the brew) orally active by protecting it from degradation in the gut. 

9) Common Names: Chacruna; Yage; Tupamaqui

Family: Rubiaceae

Genus: Psychotria

Species: viridis

Authority: R. & P. 

Folk Uses: In most parts of the Amazon Psychotria viridis, known most commonly as chacruna, is used as the primary admixture to ayahuasca. Its leaves contain high amounts of DMT that is rendered orally active by the MAO-inhibiting beta-carboline alkaloids in the vine. 


10) Common Names: Catahua; catahua blanca; catahua amarilla

Family: Euphorbiaceae

Genus: Hura

Species: crepitans

Authority: Linn. 

Folk Uses: Produces a caustic latex that is quite toxic. It is used to poison snakes, insects and fish.  The latex is sometimes taken as a violent vermifuge and purgative. It is said to be quite dangerous; a person who eats a small amount of latex may die if they do not flush with many gallons of water (Alan Shoemaker, pers. Comm.) 


11) Common Names: Ayahuasca; Azul; cuya cuya; pishco isma colorado

Family: Solanaceae

Genus: Juanulloa

Species: ochracea

Authority: Cuatr.

Folk Uses: Has the common name of ayahuasca, so may be an admixture or used similarly Duke reports it as a common admixture to ayahuasca. The Karijonas of the upper Rio Apaporis state that this curious epiphyte has “magical properties.” Their medicine men dry and pulverise the leaves, and the powder is used to treat “ear ache” (accumulation of wax?), chemically unstudied; hallucinogenic activity reported.


12) Common Names: Hierba del jergon; Jergon sacha; Fer-de-lance

Family: Araceae 

Genus: Dracontium

Species: loretense

Authority: Kraus

Folk Uses: Tuber for snakebites possibly on account of snakeskin like mottling of the petiole.  Corms are used  to control and steady the hands. roots reported edible.  Informant Alan Shoemaker says that a local doctor in Iquitos who uses traditional medicines has successfully treated several kinds of cancer using an extract of this plant combined with Una de Gato (Uncaria spp.). The mixture is injected directly into the tumor. 


13) Common Names: Cumala; oo-koo-na

Family: Myristicaceae 

Genus: Virola

Species: theiodora

Authority: (Spr. ex Bth) Warberg

Folk Uses: The ‘resin’ (sap, from the inner cambium) of this and many other Virola spp. are rich in DMT, 5-Methoxy-DMT, and other tryptamines. This species is the source of both hallucinogenic snuffs used by several indigenous groups in the upper Orinoco in Venezuela and in the Colombian Amazon. Several tribes (Bora, Makuna, and Witoto) also prepare an orally-active form of the concentrated paste. The resin is also commonly used as a topical antifungal.


14) Common Names: ko-rro-li (Kubeo) ka-ke-me-a-ma (Barasana)

Family: Marcgraviaceae 

Genus: Souroubea

Species: guianensis

Authority: Wittmack

Folk Uses: Kubeos prepare a tea of the fleshy leaves and flowers believed to hasten sleep if taken very hot in the evening.  Barasanas on Rio Piraparana boil the leaves with the seeds of Erisma japura to prepare a drink said to calm women who have been attacked by susto. Karijonas in the upper Rio Vuapes value a tea of the leaves as a tranquilizing medicine