The Web of Life – Fungi

Fungi

Out of damp and gloomy days, out of solitude, out of loveless words directed at us, conclusions grow up in us like fungus: one morning they are there, we know not how, and they gaze upon us, morose and gray. Woe to the thinker who is not the gardener but only the soil of the plants that grow in him. ~ German philosopher Friedrich Nietzsche

Fungi are a diverse group of eukaryotes with a complex classification, as there are well over a million species. Fungi fall into 2 general sizes: microscopic and macroscopic.

Fungi differ from all other life. Unlike plants and animals they form no embryos. They grow from tiny propagules, packages called spores. ~ Lynn Margulis

Fungi can be mighty hardy: thriving in harsh habitats as well as more hospitable conditions. Fungi keep their cool in deserts, savor salty settlements, not agonize over ionizing radiation, and sink without being down in deep-sea sediments. Some fungi are astronaut-ready: able to survive the intense UV and cosmic radiation encountered during space travel.

Most fungi, though, are much more down to Earth. Fungi are among the most prolific soil microbes. Topsoil averages over 8.2 tonnes of fungal mycelia per acre.

A mycelium is an integrated organism. Mycelial cords can transfer nutrients over long distances. This lets a fungus grow through soil from an established food store in search of a new supply.

Fungi are like plants in some ways but cannot produce their own food through photosynthesis. Instead, they gain nourishment by breaking down organic matter.

Most fungi are saprovores, but fungal parasites do not wait until the food is dead. They sate themselves by gnawing on the living.

Fungi are important recyclers in every ecosystem. They break down the departed, thereby burying the dead to feed the living. What fungi don’t absorb are essential nutrients that are recycled into the soil for uptake by microbes and plants.

Major fungal groups differ in reproduction, both by sexuality (asexual, sexual, or alternatively both), and by the way they produce spores. The degree of sexual diversity may seem somewhat surprising, in that all fungi evolved from a common ancestor. But sexuality is simply an adaptable life-history variable, as flexible as any other trait from an evolutionary perspective.

Fungi clearly are intelligent, even as they lack any physiology for it.

In both plants and animals, electrical and chemical signaling is known. It’s not clear what happens in a fungus. Yet multicellular fungi coordinate the distribution of nutrients and their behavioral responses. ~ Swiss microbiologist Markus Künzler

Fungi recognize each other and are territorial. If the mycelium of an individual fungus splits into smaller networks, they happily grow independently. If they later encounter one another, they may fuse back together to form a more robust mycelium by pooling resources.

If a fungus encounters a conspecific, they build chemical fences that mark territorial boundaries. In contrast, when interspecific fungi meet, war often breaks out. Each fungus produces various agents to terminate with extreme prejudice. Concoctions may be adjusted to improve toxicity. Their genome offers a variety of lethal cocktails which a fungus may choose from, as well as providing inspiration for brewing innovations.

Fungal fighters think strategically. Beset by enemies on different borders, a fungus will pick off the weakest enemy first, so as to consolidate resources for taking on stronger opponents. Bystanders may affect the outcomes of battles by emitting some of their chemical arsenals, or staging skirmishes to weaken a dominant contender.

Fungi associate with a wide variety of other organisms, often as mutualists. Their friendly relations with plants are legion. Other fungi are not so benevolent, existing as parasites and pathogens on or in plants, animals, and other fungi.

Predatory Fungi

Some fungi are predators, trapping prey in various ways. One technique is to secrete a sticky substance that latches onto lunch. Amoebae and nematode worms are typical ensnared fare.

Freshwater fungi snag rotifers. Tiny projections from hyphae appear to a rotifer like a tasty snack. Once the rotifer takes a bite of hypha, the rotifer is literally hooked. Fine branches spread throughout the rotifer’s body, digesting it and feeding the nutrients to the parent fungus.

One predatory fungus lassos its prey. It normally contents itself as a saprovore, but, if there is surfeit of nearby nematodes, it changes diet.

As soon as the fungus senses roundworms, it starts sprouting tiny loops from its hyphae. Each loop comprises 3 cells, joined end to end.

A nematode swimming by is likely to explore the loop: the oddity of an open aperture in a cramped environment. As the nematode swims within, the cells in the loop suddenly inflate, squeezing the nematode to a standstill.

The nematode panics: wriggling furiously to escape. This fruitless exercise exhausts the worm, who expires from overexertion. In contrast, a nematode with its wits about it suffers a prolonged death, as slowly growing hyphae spread through its body, consuming it.

A particularly strong nematode sometimes breaks free. The escape is but a reprieve. Snare fragments are always stuck to the worm. In time, these grow hyphae which penetrate and start to feed on the nematode.

Microscopic

Microscopic fungi were the earliest to evolve. Although fungi are ostensibly opisthokonts: organisms with flagellate cells, only the earliest – chytrids – still flail flagella.

Chytrids

Chytrids are a primordial fungus. There are 1,000 species in 127 genera. Most are saprovores. Some are plant pathogens. All are aquatic. Many are freshwater dwellers.

Chytrids may reproduce asexually or sexually. Some do both. Regardless, the next generation starts out with a tail.

Chytrids spawn sport a flagellum, whether gametes or zoospores (motile asexual spores). Chytrids are the only true fungi that reproduce by zoospores.

Chytrids keep it simple. The thallus (body) of a mature chytrid commonly comprises just a zoosporangium, typically spherical, and a rhizoid system. The zoosporangium is the main body and producer of zoospores. The rhizoids absorb and digest food, as well as anchoring the chytrid to its chosen substrate.

 Allomyces

Allomyces is a chytrid mold found in freshwater or wet soil. It forms a trunk body (thallus) that attaches via rhizoids (root-like tissues). Completing the ersatz plant analogy, reproductive organs form at the end of branches.

Allomyces mix haploid and diploid generations. A haploid thallus forms male and female gametangia which spawn flagellated gametes that attract the opposite sex by producing pheromones.

Their mating creates a zygote that develops into a diploid thallus with 2 sorts of sporangia: one which releases diploid zoospores that develop into diploid thalli, and another which releases haploid zoospores which form haploid thalli.

Yeast

Humanity’s favorite fungus by far is yeast. There are 1,500 known species, estimated to be 1% of the varieties in yeastdom.

Bread may have been baked as early as 10,000 BCE. The Egyptians were probably the first to experiment with leavened bread. They kneaded dough with their feet in large bakeries. Ancient leavening would have been for sourdough bread, using yeast and lactic acid bacteria.

 Fermentation

Beer. Now there’s a temporary solution. ~ American cartoon character Homer Simpson

Fermented beverages were enjoyed by the earliest societies in the ancient Near East. Writings from ancient Iraq, dated 5,500 BCE, mention beer.

The invention of beer predates its written description, but how early beer appeared is still bleary. Circumstantial evidence intimates that humans may have stored grain for beer before they cultivated it for bread.

The Sumerians brewed beer into poetry and the heavens: a hymn to the beer goddess Ninkasi doubles as a prayer and a recipe.

The Sumerian language had an ideogram for beer by the end of the 4th millennium BCE. Sumerian writings use a vocabulary to describe beer production that is not indigenous, and so it is likely that the Sumerians imported beer before praising it to the skies.

Beer was the favorite beverage of ancient Egyptians, as well as a staple food. Well-to-do Egyptians were entombed with an ample supply of brew for the afterlife. Even ancient Egyptians knew that staying sober isn’t what being dead is all about.

Beer was a hit in Neolithic Europe by 3,000 BCE. The brew’s popularity endured. Christian monasteries made and sold beer by the 7th century Anno Domini. Fermentation was considered a gift of God.

 Maternal Sacrifice

A mother’s willingness to sacrifice for the sake of her children is innate in many species besides humans. Female polar bears starve to nurse cubs. Dolphin mothers stop sleeping to care for newborns. Some spider moms make a meal of themselves for their hatchlings.

Yeast asexually propagate by budding; a variant of mitosis. A small daughter cell forms. This bud grows until it separates from mom.

A yeastling is typically smaller than its mother. This contradicts the classic picture of mitosis, which postulates an even splitting of cells into 2 identical copies.

Uneven division is not uncommon. Human stem cells often divide into cells that look and behave quite differently.

A yeast mother’s size reflects her generational age. Yeast grow as they get older.

When it comes to yeast, having smaller offspring does not indicate a shirking of maternal care. Quite the contrary.

Mitochondria are the power plant organelle for all eukaryotic cells. Each cell meets its energy needs by mitochondrial production.

The ratio of a yeast’s mitochondrial size to total cell size is not constant. Mitochondrial ratio declines as a yeast gains girth and ages.

As a bud grows, a yeast mother consistently provides sufficient mitochondria to the bud to ensure her daughter’s survival. In the process, mom gives more than she can recover. Hence, with each generation, a yeast mother sacrifices for her offspring.

Most yeast begin to die off after 10 generations. Few survive to 20.

 Yeast Proprioception

All organisms have a sense of orientation. ~ American biologist Paul Cullen

Proprioception is the sense of physical self, including the relative position of various body parts and their employment, and as well the energy required for movement or other activity. Yeast possess proprioception.

Yeasts are commonly colonial. How a colony grows depends upon how much it has to eat. When nutrients are plentiful, a mother yeast buds so that her daughter faces the colony.

If instead the food supply is running short, buds face outward, away from the colony. Mothers direct their daughters to form outgoing filaments, and so find food. Such change of orientation occurs within a single generation, upon realizing that the food supply is unsustainable.

Molds

Though they make an impressive visual colonial appearance on fruits and vegetables left uneaten, molds are considered microbes.

There are thousands of known mold species. All require moisture.

Like caterpillars to butterflies, mold can go through different developmental stages. Molds have the same basic growth requirements as bacteria, but typically grow much more slowly. To compensate, many molds synthesize compounds that inhibit the growth of competing microorganisms.

Slow growth coincides with the ability of molds to grow on surfaces that offer limited supplies of nutrients, such as linen and cotton cloth, and even tanned leather. At least 200 different molds have been identified from mildewed fabric, growing in brightly colored patches: blue, green, yellow, orange, pink, or brown.

 Penicillin

Scottish scientist Alexander Fleming made a serendipitous discovery in 1928. A particular mold fungus, stressed out in his lab, produced penicillin, an antibiotic.

Penicillin is a secondary metabolite of the mold Penicillium notatum, produced only when growth is inhibited by stress: never during the good times of active reproduction.

Fleming stressed Penicillium by forcing it to live in a substandard substrate, in a biotechnological process called fed-batch, purposely intended to limit growth.

Penicillin’s medical potential was figured by a team of researchers in 1938, after reading Fleming’s paper on Penicillium.

Penicillin was first applied by the researchers in 1941, on a patient infected by a rose thorn scratch, Albert Alexander. Within a day of being administered penicillin, Alexander started recovering.

But there wasn’t enough penicillin to keep dosing him to full recovery. Alexander relapsed and died.

Macroscopic

All multicellular fungi have 2 features: 1) cells with threadlike filaments (hyphae), which often have branches; and 2) special reproductive structures that prodigiously shed spores.

Few macrofungi are aquatic. The bog beacon, a water mushroom, is one. Its fruiting body rises above the surface of water from its substrate of submerged, well-decayed wood or leaf mat.

Most macrofungi grow as hyphae, at the tip of ever-expanding filaments, food supply permitting. Hyphae typically grow to form a mesh-like mass: mycelia.

Spores are the next generation of a fungus, and a sturdy hedge against dire conditions, as lightweight spores are easily airborne, and can easily withstand aridity. With the proper nutrients available, an individual spore can germinate and start its life cycle.

Like animals, all fungi are heterotrophic. Most are saprovores; collectively playing an important ecological role in nutrient recycling. A few are carnivores (150 species out of 1.5 million).

Mycelium exude enzymes that break down the meal of the moment into a simpler soup that the hyphae absorb. Specific enzymes target the food of choice.

Every naturally occurring organic material can be consumed by some type of fungus.

Macrofungi include mushrooms, toadstools, puffballs, and bracket fungi. One puffball seen in Washington state was as big as a sheep: 1.5 meters long and 1 meter wide.

Mushrooms

Mushrooms are the most famous fungi. The button mushroom is wildly popular as low-calorie garnish. Raw dietary mushrooms are a good source of B vitamins.

Other mushroom species are more sensationalist, owing to their production of secondary metabolites that are toxic or psychoactive. Like plants, mushrooms mastered the production of antibiotic and antiviral substances.

Some mushrooms possess the impressive ability to seemingly appear overnight; hence colloquiality about “mushrooming.”

A minute fruiting body forms as a 1st stage. A small button follows in the next stage. Once button-staged, a mushroom can rapidly absorb water from its mycelium and expand, mainly by inflating preformed cells which took several days to form. While such mushroom fruiting bodies are short-lived, the underlying mycelium may be massive and enduring.

Not all mushrooms quickly mushroom. Some grow slowly, adding tissue by growing from the edges of a colony, or by adding hyphae.

As wind is unreliable, mushrooms need an effective way to disperse their spores. They employ evaporative cooling. Mushrooms release small water droplets just before spore dispersal. Droplet evaporation creates vapor with enough lift to actively spread spores.

The oldest organism in the world was a humongous fungus: 2,200 years old, in over 9.7 km2 of soil, in an eastern Oregon forest. Then logging roads cut it up.

 Mycophagous Mammals

Fungi are a common food source for many creatures, notably insects and mammals. A few mammals are obligate fungus feeders.

The long-footed potoroo, known as the “rat kangaroo,” is a marsupial the size of a housecat that lives in the warm, temperate forests of southeast Australia. Its dependence on truffles circumscribes its habitat to locations where fungi are predictably available throughout the year. This changes through the seasons: riparian areas during the warm, dry summer, and into other areas of the forest during the cool, moist winter months.

The Western red-backed vole is a small rodent: 6.5–13.7 cm long, 1.8–2.1 cm high, weighing no more than 30 grams. This burrowing vole is endemic to the forests of California and Oregon. 85% or more of the Western red-backed vole’s diet is fungus, preferentially the fruiting bodies of mycorrhizal fungi that are symbionts of forest trees.

The fungi fruit on decayed timber, after its nutrients have been exhausted. Because the fruiting bodies are underground, the spores are not liberated in the air, as with most fungi.

Voles feast on the fungal fruit, and deposit their droppings, along with fungal spores, throughout their burrows. This enables a mycorrhiza to spread to unassociated trees.

There is a 3-way symbiosis going on. If a forest is clear-cut, with dead wood and trimmings removed, the mycorrhizae stop fruiting. The vole population dies out. Newly planted trees struggle to survive.

Red squirrels, common throughout Eurasia, are not obligate mycophagists, but they are quite fond of mushrooms. These arboreal rodents dry their fungal finds by hanging fruiting bodies on the branches of trees.

Once dried, which typically takes a couple of days, squirrels cache their crop of dried mushrooms in knot holes, hollow branches, or nests of twigs in the canopy, as well as cavities in tree stumps or in holes beneath logs on the ground. This distributes the fungal spores about, allowing a new generation in a new location when the rains come.

Lichen

Lichens are among the most successful macrobes in Nature, having been around for at least 480 million years, with well over extant 20,000 species. Lichens have shown enormous adaptive flexibility, including in their intimate collaborations with other life forms.

Like molds, lichens are often colorful and get by on little. They are slow growers even by the mold standard.

Lichens are long-lived. In favorable conditions, a lichen may survive many thousands of years.

Lichens compete with plants for sunlight access, but because they have a leisurely growth and are small, they can thrive where higher plants struggle to gain a roothold.

Several ground-dwelling lichen species have the wiles to preclude competition from plants. They produce metabolites that leach into the soil and inhibit seed germination and young plant growth. The result can be a lichen glade: a few scattered trees in terrain dominated by lichen. Lichen glades are more common in high elevations or high latitudes in the northern hemisphere.

Lichens are widespread around the world. Lichens appear in the most extreme environments, including arctic tundra, scorching deserts, rocky coasts, and toxic slag heaps. ~6% of Earth’s land surface is covered by lichens.

Lichens can even survive in space. They also enjoy the temperate life, in lush rain forests and woodlands, as well as on bare rock and soil.

While classified as fungi, all lichens are composite organisms: a fungus (mycobiont) in a symbiotic mutualism with a photosynthesizing alga and/or cyanobacterium (photobiont). Some also incorporate a 2nd fungus – a yeast – into themselves. A few have 2 different phototrophs, usually a green alga and a cyanobacterium. The advantage of being more cosmopolitan is not known.

The photobiont makes enough carbohydrate food for both partners via photosynthesis. The mycobiont provides the home. The mycobiont manages growth and contributes mineral nutrients, obtained by chewing on the rock or substrate that the lichen is clinging to.

There’s a mix-and-match aspect to lichen. The same algae species may be popular with more than 1 lichen-forming fungus.

A principal reason for lichen success is their ability to feed on air. They get most everything they need – moisture and nutrients – from the atmosphere; except, of course, the modest mineral contribution of the mycobiont.

Being air feeders, it may seem that a fungus’s preferred partner would be a cyanobacterium, as most of them can fix atmospheric nitrogen, and so supply this valuable nutrient. Surprisingly, cyanobacteria are not a fungus’s preferred partner. This indifference may owe to lifestyle: lichen grow so slowly that an abundance of nitrogen would be wasted wealth. A lichen gets all the nitrogen it needs from the minute amount of ammonia in the air, supplemented with the substrate that gets munched on by the mycobiont.

The nitrogen situation is different for tripartite lichen (those that are a fungus, green alga, and cyanobacterium). The cyanobacteria in these triads vigorously fix nitrogen. These lichens tend to be relatively rapid growers.

The mutualism of the microbial participants in lichens is not obligatory. Mycobionts are also found in a free-living lifestyle. Only 20% of lichen species are obliged to be symbiotic with photobionts.

Many lichens reproduce asexually, either by physical separation (vegetative reproduction) or by dispersing diaspores containing a few algal cells swathed in fungal cells. Asexual reproduction does not lessen the capability of lichen to speciate if the appropriate opportunity arises.

The fungal mycobiont in a lichen may reproduce sexually. Many do so, producing spores that spread to new land. In their youth, these fungi must meet a compatible photobiont to marry and take up the lichen lifestyle.

Lichens may have long lives, but many are sensitive to pollution and contamination, as they accumulate toxins without any means to expel foul chemicals. The more dependent upon its photobiont a mycobiont is, the more sensitive it is to air pollution.

Lichens are a major food source for reindeer. 90% of the winter diet of Artic reindeer is lichen, even when covered with snow. Reindeer can smell lichen through the snow and dig down to get it. Occasionally there are fights over a good lichen patch.

Humans use lichens to make perfumes and dyes. Lichens are also mixed into traditional medicines.

Pathogens

Several fungi are pathogenic to plants and animals. As with other pathogens, fungi can be wily.

 Candida

Candida albicans is a microscopic dimorphic fungus. Most of the time it exists as single yeast cells which reproduce by budding. C. albicans can also reproduce sexually.

Most yeasts do not produce mycelia but C. albicans can create a colony via hyphal filaments. C. albicans choses its form according to ambient conditions. At room temperature, single cells seem best. But sensing itself inside a warm body with the proper pH, C. albicans may develop into mycelial form, to better appreciate its environment. Its decision to turn mycelial is made by quorum-sensing.

C. albicans is typically commensal to humans; an eve-ryday member of gut flora, as well residing on the skin and mucosal surfaces. C. albicans lives in 80% of the human population without incident.

C. albicans senses the status of its host’s immune response. If the immune system is weak, C. albicans may decide wreak havoc by turning pathogenic.

 Ergot

Saint Anthony’s fire was a dreaded Medieval affliction, caused by consuming grain infected with ergot fungus. Symptoms include convulsions, nausea, vomiting, diarrhea, headaches, and hallucinations.

The name came from the 12th-century monks of the Order of St. Anthony, who were especially successful at treating this disorder using balms and herbs that stimulated circulation, to accelerate flushing the drug from the system.

The fungus Claviceps purpurea produces ergot when growing on rye or other grains. Ergot is a brew of powerful chemicals, including a substance that transposes into the hallucinogen LSD.

When milled, ergot in grain reduces to a red powder, which is obvious in lighter grasses, such as millet, but easily overlooked in dark rye flour.

Convulsive ergotism is caused by eating fungal-infected bread. Rye, historically the grain of the poor because of its hardy ability to grow on relatively poor soil, is especially susceptible to ergot.

The fire of ergot was known to the ancients. Assyrians were acquainted with the disease by 600 BCE. Erogotism waned during Roman times only because the Romans did not care for rye.

Epidemics of the ergotism recurred throughout history into the 19th century. Saint Anthony’s fire was repeatedly lit in medieval Europe because rye was a major cereal crop, and ravenous peasants were none too careful. Entire villages were ravaged. In 994, 40,000 in central France succumbed to ergotism.

The notorious Salem, Massachusetts witch trials (1692 – 1693), where women and children were hanged for being servants of Satan, may have been spurred by the spasmodic symptoms of eating ergot-tainted rye. Court records list symptoms of “bewitchment” that read like the physical manifestations of psychedelic trips.

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Controlled doses of the ergot alkaloids have been used to treat migraine headaches and strengthen uterine contractions in childbirth.

Lysergic acid is a derived or synthesized precursor of ergot alkaloids. D-lysergic acid (LSD) was first synthesized by Swiss chemist Albert Hofmann in 1938, who got high in the Alps by accidentally absorbing a bit through his fingertips in 1943. Hofmann recorded the psychedelic experience as: “a not unpleasant intoxicated-like condition, characterized by an extremely stimulated imagination. In a dreamlike state, with eyes closed (I found the daylight to be unpleasantly glaring), I perceived an uninterrupted stream of fantastic pictures, extraordinary shapes with intense, kaleidoscopic play of colors.”

 Potato Blight

Potatoes grow wild throughout the Americas, but domesticated potatoes have a single historical origin: Peru, where they were first grown 7,000 to 10,000 years ago. Spanish conquistadors subjugated the Inca Indians of Peru in the 16th century, taking potatoes back to Europe as captives.

European farmers were at first skeptical of the spud, but famines in the early 1770s put potatoes in the ground and on the menu. While the French stubbornly snubbed the spud until 1800, the hardy potato quickly became a staple in Ireland, as it was a food crop that landless laborers, renting tiny plots from their landowners, could grow.

A single acre of potatoes and milk from a solitary cow could feed a whole family. The landowners were only interested in raising cattle and growing grain.

The Irish population exploded, with the potato as the staple diet of the poor. The same potato species was widespread throughout Ireland.

Irish newspapers in 1843 had reports of a disease destroying potato crops in America. In 1844, late blight arrived. Phytophthora infestans, an oomycete, which is a fungal cousin, causes late blight.

The devastating blight swiftly spread through the poorer communities of western Ireland, resulting in the crop failures that led to the Great Irish Famine, which killed over a million and wrecked the Irish economy. The circular irony is that the great Irish wave of immigration to the United States resulted from the potato blight, which came from America.

 Fungal Voices

For something with no discernable intellect, some fungi possess considerable capacity to affect the minds of others.

 Death Grip

This is a microbe controlling an animal – the one without the brain controls the one with the brain. ~ American entomologist David Hughes

The fungus Ophiocordyceps unilateralis infects carpenter ants. At the end of its life cycle, the fungus causes full body convolutions in an infected arboreal carpenter ant that sends the ant to the forest floor.

The fungus then induces the ant to climb a plant to a particular place favorable to the fungus. The ant positions itself on the underside of a low-hanging leaf, then makes one last powerful bite that holds it in place.

After planting its mandibles, the ant expires.

O. unilateralis then grows a spore-bearing stalk out of the ant’s neck. After 4–10 days preparation, this fruiting body then releases its spores.

O. unilateralis has an exceptional practice of mind control in inducing numerous specific behaviors in car-penter ants.

An infected ant found in the nest would be immediately removed. So, the fungus marches an infected ant away from the colony, but into the path of foragers; a sniper’s alley for future hosts.

The fungus is also smart enough to stick to its core competency. While O. unilateralis may infect other ants, it does not attempt to turn them into zombies.

The fungus produces a specific array of compounds as a reaction to the presence of the host brain it has evolved to manipulate. ~ American entomologist Charissa de Bekker et al

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Ants are not the only creature to hear fungus talk. Psychedelic fungi have played a historically significant role in enlightening humans.

 Fungus of the Gods

The magic mushroom Amanita muscaria may have lent its power in the formulation of Hinduism as the “soma” in ancient Vedic scriptures.

Soma is portrayed in the seminal Vedas as a spiritual trifecta: sacred, a god (deva), and a drink. The Rig Veda hymn of Soma proclaims that drinking soma grants immortality, like ambrosia in ancient Greek mythology: both what the gods quaff, and what makes one a god.

We have drunk Soma and become immortal; we have attained the light, the Gods discovered. Now what may foeman’s malice do to harm us? What, O Immortal, mortal man’s deception? ~ Rig Veda 8.48.3

The suggestion that soma was psychotropic has been controversial. Ephedra sinica has been considered soma candidate. E. sinica is an ancient cold remedy, unlikely to stimulate such florid self-realization of mortal man’s deception.

Ancient Siberians employed A. muscaria in their shamanic rituals. Shamans were ubiquitous among indigenous tribes from prehistory onwards. One of their roles was messenger and intermediary between the human world and the spirit plane. Ingesting psychotropic substances, such as psilocybin mushrooms and peyote, to better access the spirit world has long been a shamanic tradition.

The common name for A. muscaria is fly agaric – not because it works as a pesticide, but rather from the delirium its consumption induces. Medieval lore had it that flies could penetrate a person’s head and render them deranged.

From the ancient Greek, agaric is the term for the fruit of a mushroom. Psychotropic mushrooms, including A. muscaria, were known to the ancient Greeks. Perhaps soma and ambrosia were the same.

To test the pesticide hypothesis, researchers exposed flies to fly agaric. It did not kill them. Their behavior was observed as having got a buzz (intoxicated). Apparently, fly agaric turns flies into gods, who may then see past their own mortal deception.