A psychedelic tour of Earth’s ecosystems – from the desert to Siberia

Every mind-bending molecule in nature has an evolutionary origin; a defence against being eaten, a lure for pollinators, or perhaps a happy biochemical accident. Though they seem extraordinary, life has evolved psychedelic molecules that alter consciousness across almost every ecosystem.

Let’s take a tour of our surprisingly psychedelic planet.

The tropical rainforests hum with chemical diversity. Among the 10,000 tree species living in the Amazon are several which produce dimethyltryptamine (DMT), the molecule that makes psychedelic brew ayahuasca so powerful. DMT is a naturally occurring tryptamine molecule, which derives from the same chemical building block that gives us serotonin and melatonin, chemical messengers that change our mood and help us sleep.

Read more: Creating insulin-producing islets for transplantation

One of these tree species, the Psychotria viridis, or chacruna, is a small understory tree from the plant family that also gives us coffee. Other DMT-producing species include yopo (Anadenanthera peregrina), a tree native to the Amazon that is also found in the Caribbean. Yopo is in the legume family, a close relative of beans, chickpeas and lentils. Scientists aren’t sure why some species in the same family develop psychedelic compounds while others don’t.

Many people think of plants as nice-looking greens. Essential for clean air, yes, but simple organisms. A step change in research is shaking up the way scientists think about plants: they are far more complex and more like us than you might imagine. This blossoming field of science is too delightful to do it justice in one or two stories. This article is part of a series, Plant Curious, exploring scientific studies that challenge the way you view plantlife.

Many tryptamine compounds like DMT are thought to have evolved in plants as chemical defences against herbivores and pathogens, the result of an evolutionary arms race going back millions of years. Scientists are not yet sure which species the plants were trying to defend against.

The deserts may not appear to hum with life. Their extreme heat, punishing aridity and sparse vegetation make survival seem improbable, and the organisms that persist often look strange.

However, deserts have given rise to powerfully psychedelic organisms. The peyote cactus is small and round and lives in the deserts of Mexico and south Texas, where it grows extremely slowly, often taking decades to reach maturity. Peyote is threatened as it is subject to intense poaching by collectors and recreational users of the mescaline it produces, a psychedelic alkaloid.

Alkaloids are part of the same chemical class as caffeine and nicotine, and are also thought to have evolved to defend plants against herbivores. Desert-living peyote are not the only psychedelic cactus though. A distant cousin of the high Andes, the San Pedro cactus (Trichocereus macrogonus var. pachanoi), also produces mescaline. But unlike peyote, San Pedro grows fast and tall.

Beyond cacti, the Sonoran desert is host to the Sonoran Desert toad, which produces one of the most potent hallucinogens known to scientists, 5-MeO-DMT.

Tundra and toadstools

Like the deserts, the tundra hardly appears a friendly place to live. But even in the frozen north of Siberia, psychedelics can be found. When asked to visualise a toadstool, many of us will picture a red-capped mushroom with white spots. This is the fly agaric (Amanita muscaria), a species complex with a distribution in the boreal and temperate forests of the northern hemisphere including the UK, that originated in Siberia or Beringia.

Fly agaric produces psychedelic compounds including muscimol and ibotenic acid, which differ chemically from the more well-known psilocybin, but are also hallucinogenic. Like the psychedelic trees of the Amazon, mushrooms probably evolved these molecules specifically to put off animals that might eat them.

This mushroom has plenty of lore, spanning Viking berserkers, early Christianity and even the Father Christmas tradition. Whether these stories are true is up for debate, but we know there is deep use in indigenous cultures. We also know how important the fly agaric is for many trees including birch and oak, with which it forms symbiotic relationships, helping trees survive in the soil.

The world’s grasslands might appear serene, but they host one of nature’s darker psychedelic stories.

Hidden among the grains lives ergot (Claviceps purpurea), a tiny fungus which fills grass seeds with ergot alkaloids. These compounds, the chemical cousins of LSD, have haunted humanity for centuries. In the middle ages, outbreaks of ergot poisoning caused mass hallucinations and hysteria throughout Europe. Entire villages succumbed to visions and manic dancing, often attributed to demonic possession.

In 1938, the Swiss chemist Albert Hofmann synthesised LSD (lysergic acid diethylamide) from ergot molecules. The consequences of this discovery shaped modern culture and technology, even inspiring a Nobel prize winner to invent the PCR reaction that underlies modern genetic research and COVID testing.

Beyond ergot, the temperate grasslands are host to the liberty cap (Psilocybe semilanceata). This is a common and unassuming mushroom that produces some of the highest concentrations of psilocybin and psilocin, powerful psychedelic molecules. It is one of the most abundant mushrooms in some regions and grows undetected in many back gardens. The liberty cap recycles decaying grass and sedge roots, playing an important role in its ecosystem. And lab studies in the early 2000s discovered it also produces antimicrobial compounds, to prevent pathogens growing on it.

Some psychedelic species are found all over the planet. The psilocybin and psilocin producing mushrooms of genus Psilocybe can be found in regions as diverse as the Mexican highlands, Australia, India and Japan. Several species of common ornamental grasses (Phalaris) living in the US and Eurasia produce DMT, as do certain Australian species of Acacia and South American Mimosa, which are in the legume family.

Curiously, DMT has also been found in small amounts in mammals, including humans, where it may possibly act as a neuromodulator, a molecule facilitating communication between neurons.

This is only scratching the surface of Earth’s psychedelic supply. The Golden Guide to Hallucinogenic Plants by Amazon explorer Richard Evans Schultes, published in 1976, describes over 100 plant and fungi species.

And this field of research is still young. Two new Psilocybe mushroom species, which both produce psilocybin, were scientifically recorded in southern Africa only in 2023. Recent work suggests that the 400,000 plant species alone may produce millions of unique molecules, with more than 99% of these unknown and not characterised in a lab. We do not even know how many fungal species there are, but there are likely to be millions, most yet to be discovered.

This article is republished from The Conversation, a nonprofit, independent news organization bringing you facts and trustworthy analysis to help you make sense of our complex world. It was written by: Jamie Thompson, University of Reading

Read more:

• Liberty cap: the surprising tale of how Europe’s magic mushroom got its name
• Most plant-friendly fungi are a mystery to scientists
• From trips to treatments: how psychedelics could revolutionise anti-inflammatory medicine

Jamie Thompson does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.