Entangled Life: How Fungi Make Our Worlds, Change Our Minds and Shape Our Futures

by Merlin Sheldrake

there are few pockets of the globe where fungi can’t be found. Tens to hundreds of species can exist in the leaves and stems of a single plant. These fungi weave themselves through the gaps between plant cells in an intimate brocade and help to defend plants against disease. No plant grown under natural conditions has been found without these fungi; they are as much a part of planthood as leaves or roots.

It’s amazing to observe the diversity of fungi that crowd into even small patches of leaf. Place a hole-punch sized circle of leaf on a dish and you can see them emerge over the course of a few days as they unpack themselves from the plant cells — a display of fuzzy reds, purples, blues, yellows, whites, browns seeping outwards.

We all live and breathe fungi, thanks to the prolific abilities of fungal fruiting bodies to disperse spores. Some species discharge spores explosively, which accelerate 10,000 times faster than a Space Shuttle directly after launch, reaching speeds of up to a hundred kilometres per hour – some of the quickest movements achieved by any living organism.

While writing and editing the book I would read these numbers and double take. It happened frequently. On one occasion, convinced that I must have made an appalling clerical error, I contacted the world expert on these fungal species to check the figures. They were correct, he confirmed. Despite my familiarity with these statistics I had stumbled over my disbelief — yet again. It remains a hazard. Fungal behaviours frequently defy our expectations even if we’re expecting them to do so.

Fruiting bodies, such as mushrooms, arise from the felting together of hyphal strands. These organs can perform many feats besides expelling spores. Some, like truffles, produce aromas that have made them among the most expensive foods in the world. Others, like shaggy ink cap mushrooms (Coprinus comatus), can push their way through asphalt and lift heavy paving stones, although they are not themselves a tough material. Pick an ink cap and you can fry it up and eat it. Leave it in a jar, and its bright white flesh will deliquesce into a pitch-black ink over the course of a few days (the illustrations in this book were drawn with Coprinus ink).

I’ve seen this many times but it never ceases to astonish me. A solid mushroom becomes liquid. A bright white turns to a deep, obsidian black. You can almost watch it happening. The ink caps that made the ink for the illustrations in the book came from a park in Montreal. I ate a few and left a couple to deliquesce. I then sent the ink to the artist Collin Elder for him to experiment with. The ink was quite thin and to start with he layered it up in layers on the page. After a while he started concentrating it. The textures he gets are fantastic, from sharp lines to light washes. Inks are mesmerising. A friend of mine makes beautiful inks and I’m often surprised at how the colours on the page can differ radically from the colour of the raw material. Buckthorn berries, for example, are purple and make a purple ink which turns a wonderful sap green as it dries.

The indigenous peoples of Australia treated wounds with moulds harvested from the shaded side of eucalyptus trees. The Jewish Talmud features a mould cure known as ‘chamka’, consisting of mouldy corn soaked in date wine. Ancient Egyptian papyruses from 1500 BCE refer to the curative properties of mould, and in 1640 the King’s herbalist in London, John Parkinson, described the use of moulds to treat wounds.

The literature on traditional mould cures is fascinating. A researcher in England, Milton Wainwright, became interested in the subject and amassed a database of people’s accounts. One person described their grandfather’s method of scraping the green mould from hams hanging from the rafters. Another described the practice — apparently common in European farmhouses — of keeping a mouldy loaf of bread on the beams in the kitchen which could be made into a poultice for wounds. I went to visit Milton and spent hours listening to his stories. Another of his interests is maggot therapy. This is a traditional technique, practiced for hundreds of years, in which live maggots are let loose within wounds. The maggots eat the dead tissue (known as ‘debriding’) and their saliva disinfects the wound. After a while you remove the maggots. It turns out that there is nothing more effective. Maggot therapy has had a recent resurgence and is now a standard hospital technique in many places and packets of sterile maggots can be ordered from medical supply companies. I asked if it was painful. Milton laughed and explained that it could feel a little strange — the maggots are fond of grazing on nerve endings.

Penicillin, a compound that could defend fungi from bacterial infection, turned out to defend humans as well. This is not unusual: although fungi have long been lumped together with plants, they are actually more closely related to animals – an example of the kind of category mistake researchers regularly make in their struggle to understand fungal lives.

The story of penicillin has some great twists and turns. After penicillin had been purified but before it had become widely available news circulated in the medical community about its remarkable curative powers. Crude ‘kitchen sink’ extracts were made by doctors and in some cases pads made of the living mould were applied to wounds directly, allowing the fungus to fight it out with the bacteria in real time, in situ. I’ve grown pads from penicillin moulds to see what it would be like to dress a wound with them although I never had an infection to treat. I toyed with the idea of giving myself two identical wounds, one on each leg, infecting them, and treating one with mould and leaving the other untreated to see which healed faster. I came to the conclusion that intentionally creating festering sores was perhaps a little reckless and shelved the experiment, although I’m still curious about what would happen.

The jungle bristled with life. There were sloths, pumas, snakes, crocodiles; there were basilisk lizards that could run across the surface of water without sinking. In just a few hectares there lived as many woody plant species as in the whole of Europe. The diversity of the forest was reflected in the rich variety of field biologists who came there to study it.

The field station was an astonishing place to live. The spectrum of ordinary to extraordinary warped in often hilarious ways. I remember one night as I left my lab I ran into a colleague who had been having a hard day. “My samples were singed in the drying oven,” she despaired, “my clothes are filthy because someone put their muddy jungle boots in the washing machine, and a box full of bottles of tree sap fell off a shelf and bruised my ankle.” I always wanted to write an opera or a sitcom set at a jungle field station. It hasn’t happened yet.

A friend of mine, the philosopher and magician David Abram, used to be the house magician at Alice’s Restaurant, in Massachusetts (made famous by the Arlo Guthrie song). Every night he passed around the tables; coins walked through his fingers, reappeared exactly where they shouldn’t, disappeared again, divided in two, vanished into nothing.

Alice’s restaurant started off as a small greasy spoon but after Arlo Guthrie released his song the establishment gained so much notoriety that it expanded and moved to the neighbouring town. In David’s words, “Alice had a ruby inlaid in one of her front teeth, and she was always kind and generous to me: ‘Hey magishun: How's tricks?’ she would ask each day upon first seeing me, to which I'd reply: ‘Just fine, Alice: What's cookin?’”

Physarum form exploratory networks made of tentacle-like veins, and have no central nervous system – or anything that resembles one. Yet they can ‘make decisions’ by comparing a range of possible courses of action, and can find the shortest path between two points in a labyrinth. Japanese researchers released slime moulds into petri dishes modelled on the Greater Tokyo area. Oat flakes marked major urban hubs and bright lights represented obstacles such as mountains – slime moulds don’t like light. After a day, the slime mould had found the most efficient route between the oats, emanating into a network almost identical to Tokyo’s existing rail network.

I’m writing from lockdown in the UK and have two glass dishes of slime mould as part of my quaranteam. It’s amazing to watch them distribute themselves. A friend joked with me about a ’slime mould oracle’ that he liked to create, which I’m yet to try. You ask a question, and place two oats equal distances from the slime mould, one labelled ‘yes’ and the other labelled ‘no’. The slime mould network emanates outwards and whichever it reaches first is the answer. There is an active online community of slime mould enthusiasts (The Slime Mould Collective: “An international network of / for intelligent organisms”) who share their findings and experiences, and document the various unexpected feats of these paradigm-busting creatures. It’s well worth a visit.

I had a professor called Oliver Rackham, an ecologist and historian, who studied the ways in which ecosystems have shaped – and been shaped by – human cultures for thousands of years. He took us to nearby forests, and told us about the history of these places and their human inhabitants by reading the twists and splits in the branches of old oak trees, by observing where nettles thrived, by noting which plants did or didn’t grow in a hedgerow. Under Rackham’s influence, the clean line I had imagined dividing ‘nature’ and ‘culture’ started to blur.

Oliver was a wonderful teacher and very eccentric. His field trips were a roving one-man show, his stagecraft antique and understated. He would test us: “Why are the primroses and bluebells on the woodland floor growing in lines?” We’d um and ah, usually in vain. After a while he’d give us the answers with a quiet flourish: “The primroses and bluebells reveal the ridges and furrows left behind by medieval ploughs which worked this land before it became woodland in the thirteenth century.” He was a kind of sleuth and started a new discipline called historical ecology.

I spent whole months staring into a microscope, immersed in rootscapes filled with winding hyphae frozen in ambiguous acts of intercourse with plant cells. Still, the fungi I could see were dead, embalmed and rendered in false colours. I felt like a clumsy sleuth. While I crouched for weeks scraping mud into small tubes, toucans croaked, howler monkeys roared, lianas tangled and anteaters licked.

To see fungi within roots you have to boil them in an alkaline substance to ‘clear’ them and then stain them using a blue dye. The dye is poisonous and a pain to handle, but the indigo washes that it makes are quite beautiful. Emerging from the microscope was a bit like surfacing after a dive. I spent so long in these rootscapes — full days looking down the microscope for weeks on end — that I would see root forms when I closed my eyes. I even had indigo-drenched dreams, in which I felt that I was looking at everything through blue tinted glasses.

I wanted to use the LSD trial to think more broadly about the lives of the blue flowers, Voyria, and their fungal relationships. How did they live without photosynthesis? Almost all plants sustain themselves by drawing minerals from mycorrhizal fungal networks in the soil; so did Voyria, judging by the tousled mass of fungi that crowded into their roots. But without photosynthesis, Voyria had no way to make the energy-rich sugars and lipids they needed to grow. Where did Voyria get their energy from?

Later I was able to look inside the roots of the blue flowers in almost psychedelic detail using a type of microscope that makes it possible to produce 3D scans. It’s possible to journey through these vivid rootscapes on a computer, almost like a planetarium show (I’ve posted some on my social media channels). A dream of mine is to convert these scans into a VR experience, or even 3D print them enormously enlarged and stage an exhibition where people can clamber around inside the roots to get an intuitive sense of these hidden subterranean worlds and their intimacies.