Mushrooms Are Sexy Part I – A Spore to Shroom View of Fungal Bio

Editor’s Note:

Well, I’ve managed to go more than a week without posting to this blog, and the reason is simple but a little reprehensible; you see, it’s officially chanterelle mushroom season in North Carolina, and all the time I normally dedicate to writing about fungi has been sucked up by forest-time and quietly walking around looking for these dainty, delicious golden beauties. Well, not all; as you will soon see, I’ve cooked up a post that covers some of the fundamental understandings of mycology and mushroom-ology, and it got so long that I had to split into two separate entries. The second will follow once I have a minute to clean it up and post it. As any mushroom fanatic will tell you, coming to understand how and when fungi reproduce is extremely helpful for those who wish to find wild mushrooms or cultivate them at home.

This is a broad exploration of the sex lives of mushrooms, coupled with observations about the importance of fungi to different habitats. We’ll also look at a little bit of history of mushroom taxonomy, an explanation of the difference between mold and mushrooms, and a few other random things besides. I hope you enjoy it! In the meantime, happy hunting!

Yours In Fungal Fancy,

Mushroom Anna

 

A Spore-To-Shroom View of Fungal Biology: The Life and Times of Mushroom Mycelium

Paul Stamets
Paul Stamets, owner and founder of Fungi Perfecti, lifting a mycoboom made of straw and oyster mushroom mycelium into the waters of the Puget Sound. Photo by Anna McHugh.

“I think it’s the ultimate hubris that the human species thinks we are the only intelligent organisms on this planet. I think that is extremely provincial from a biological point of view.

Let’s go back in time. We share more common ancestry with fungi than we do with any other kingdom. In fact, in the Journal of Eukaryotic Microbiology a few years ago, a new super kingdom has been erected called Opisthokonta (that) joins Animalia and Fungi together into one kingdom because of our common ancestry. We exhale carbon dioxide, so do fungi. We inhale oxygen, so do fungi.

So we have a common ancestor, and these (fungal) networks that have evolved are resilient, and they are intelligent. What I mean by that is that one side of a network can have an experience with an antagonist, with a bacterium or a new food source, and if successful, the mycelium the goes through a recombination of DNA.

The mycelial strands grow into that new food source, and there is a “memory” that then is back- channeled through the network. The network is becoming educated genetically. So, these networks are extremely adaptive to catastrophia. They evolve very, very quickly, and through natural selection these networks have emerged in a manner that allows them to cope with change.

I think one measure of intelligence is not only the ability to adapt to change, but to predict and pre-position oneself for changes in the environment. I think fungi do that in a very exquisite way.”

~Transcript exerpt from my interview with Paul Stamets, mycologist and founder of Fungi Perfecti

Mushrooms are inherently sexual. Truffles contain aromatic oils that are very closely related to human pheromones, which might be the reason that chefs and foodies are so turned on by them. Truffles tease pigs as well, and for eons truffle hunters raised sows to hunt for these subterranean lumps of precious fungus. A lady pig is highly susceptible to the scent of truffle, and when she smells it at the base of an oak or filbert tree it gets her hot and bothered.

Black truffle
This 250-gram black truffle sold for 105 Euros at auction. Photo by David Monniaux. Licensed under Creative Commons Attribution-ShareAlike 2.0 France.

For whatever reason, the stink of truffle has something of the husky hog in its aroma, and a sow can root out a sex-scented truffle buried several inches deep in the soil. Much to her dismay, Pig’s human counterpart traditionally breaks off the tryst at this point with a stick and snags the prize for himself.

Human enthusiasm for truffles certainly rivals our lady Pig; in 2005 a casino owner named Stanley Ho paid $330,000 for a single truffle at the astonishing price of $100,000 per pound.

A mushroom that belongs to the genus Dictyophora or Phallus (depending on who you talk to) is as controversial as it is sexy. Distinctly penis-shaped and housed inside an interlocking network of tissue that falls around it like a crocheted cloak, one tropical strain of Dictyophora indusiata invites comments both lewd and laudatory. Dictyophora mushrooms produce a pungent odor that mimics the scent of animal feces and rotting meat.

From an evolutionary standpoint, the foul smell of this mushrooms and its kin, commonly called stink horns (for obvious reasons), is quite a clever development. The fungus spores develop on the fruiting body’s lacy outer skirt and the stench attracts flies and other insects. Bugs are maddened by the enticement of fresh poop and decay and bang into the tissue that bulges out around the phallic protrusion of the mushroom, knocking spores loose into air currents that carry fungal DNA far and wide. The bug-attracting, stink-producing trait is not the source of controversy that surrounds this lurid mushroom, but anyone who has passed by a fungus of this sort can attest to its powerful and revolting aroma.

Some years ago at a conference, mycologist and keynote speaker Dr. J.C. Holliday posed an interesting theory drawn from an article he and a co-author published in The International Journal of Medicinal Mushrooms. The name of this article was certainly a crowd-pleaser: “Spontaneous Female Orgasms Triggered by Smell of a Newly Found Tropical Dictyphora Species.” Holliday told his incredulous audience that he found a special Dictyophora that produces a chemical that mimics human pheromones, one whiff of which arouses women to the point of sexual climax.

During my travels I interviewed two people about the this weird phenomenon. One of them attended Dr. Holliday’s lecture and said he was deeply skeptical of Holliday’s “sexy mushroom” theory. In the spirit of good faith, my interviewee approached the doctor after the talk and asked for clarification, assuming that if it were a bad joke the respectable mycologist would not be able to hold it together. After a few minutes of grave conversation with Dr. Holliday, my interviewee was convinced that the doctor truly believed in the hypothesis.

Dictyophora indusiata
The incomparably gross Dictyophora indusiata. Photo by Shashidhara halady. Licensed under Creative Commons Attribution-ShareAlike 3.0 Unported.

Another mycologist I spoke with, a mild-mannered young fellow from San Francisco, got angry the moment I uttered the word “Dictyophora.” He accused Dr. Holliday of cooking up the whole story as a cruel joke, a mean-spirited attempt to convince lady mycologists to sniff one of the most disgusting mushrooms in all creation.

Considering that this special Dictyophora supposedly grows only in the tropics I myself cannot weigh in on its sexiness, but this anecdata hints at our sensual relationship with the curious fungi.

Above and beyond powerful attraction between certain people, pigs and mushrooms, there is the basic biology of fungus to be considered when evaluating their sexiness. A mushroom is the reproductive mechanism of certain types of fungi, an explosive and unique growth with the sole purpose of distributing genetic material.

Mushrooms drop huge loads of spores, which germinate and recombine with one another to create genetically distinct strands of fungus. Ganoderma applanatum, commonly known as the Artist’s Conk, drops more than five trillion spores each year. This woody, porous fungus grows perennially on trees and is very long-lived. The abundant sporulation of Ganoderma applanatum is an exemplary case of fungal reproduction. Spores require very particular conditions to germinate and survive, and so fungi compensate by producing them in vast numbers.

Even more drastic are the green and black molds that proliferate wherever fungus can find food and moisture. On average, these organisms outstrip the spore count of mushroom-bearing fungi by a factor of ten. Thus, much of the pulmonary devilment caused by fungi is the consequence of mold spores, not mushroom spores. Fungi that make mushrooms do not often bother human noses and throats, as luck would have it; they simply aren’t numerous enough to do so.

Basically, mushrooms are the way certain fungi have sex. Most people think that mushrooms and fungus are the one and the same, but strictly speaking this is not true. Mushrooms are the biological expressions of the fungal body. It’s fruit. The true fungal body is called mycelium, a delicate network of cells that grows through wood, soil, and other organic material. Mycelium quests through its environment in search of food and moisture, absorbing both through its cell walls and secreting enzymes into its surroundings in order to digest food, fight off disease, and compete with its neighbors.

Mycelium is highly responsive to its environment, and channels resources to parts of the fungal network that most need them. When mycelium fruits, it sends a surge of moisture into the specialized cells that make up the developing mushroom drawn from all corners of the mycelial mat.

Oyster Mushroom Mycelium Growing on Coffee Grounds
Oyster mushroom mycelium growing on coffee grounds. Photo by Tobi Kellner. Licensed under Creative Commons Attribution-ShareAlike 3.0 Unported.

Mycelium is literally everywhere: in each cubic inch of healthy soil, there is roughly eight miles of mycelium if each cell were laid end to end, and there are about 14 billion tons of mycelium worldwide. The network of a single fungus can also grow to tremendous size and age.

The largest known organism on earth is a mycelium that permeates about 2,200 acres in the Malheur National Forest in eastern Oregon. It is unclear how old this monster is exactly, but it’s been around for at least 2,400 years, making it one of the oldest living beings on the planet as well1.

This fantastically large mycelium is an Armillaria oystae, which produces an edible mushroom that belongs to a cluster of species commonly called honey mushrooms. Another honey mushroom mycelium of the species Armillaria gallica was found in Michigan that was estimated to be 1,500 years old and weighs roughly 220,000 lbs.

Mushroom Growth and Development

When environmental conditions are just right, mushrooms pop up and drop spores imprinted with the parent mycelium’s DNA. The rapidity of mushroom development varies quite a lot, depending on genetic and environmental factors.

The fast-fruiting Coprinus comatus, or Shaggy Mane, explodes from the soil and can lift paving stones clear off the ground. Shortly after this staggering feat of fungal puissance, shaggy manes decompose, and the mushrooms transform into unrecognizable goo within the span of a few hours. By contrast, the edible chanterelle takes about 3 weeks to mature and sporulate. Mushrooms form slowly during dry spells, and may not reach the size and stature of mushrooms swollen by rainwater.

Given adequate moisture and nutrition, mushroom spores germinate and sprout hyphae, microscopic tendrils of fungal tissue that grow through the habitat in search of food and a mate. A typical hypha only has half of the chromosomes necessary to create a new fungus, and so each strand must find a partner to fuse with. In this way, each mushroom spore has a “sex,” although this is a bit deceptive if one is thinking solely in terms of “male” and “female” hyphae.

Coprinus comatus
The shaggy mane mushroom, Coprinus comatus, grows fast and decomposes even faster. Photo by Tommy Kronkvist. Licensed under Creative Commons Attribution-ShareAlike 3.0 Unported.

Mushroom spores have the capacity to fuse into literally thousands of possible genetic combinations. The shiitake, one of the most commonly cultivated mushrooms in the world, has roughly 22,000 possible genetic expressions or “sexes.”

Once two suitable hyphae mate, they fuse and form a branching network of tissue that is genetically distinct from the parent fungus. This new mycelium repeats the fungal lifecycle, exploring and interacting with its habitat and, when the conditions are right, producing its own fruiting bodies.

How Many Fungi Are There?

The tree of life has six branches and the fungal kingdom is one of them. There are roughly a million and a half species of fungi. Scientists have names for roughly 75,000 species, a mere 5% of the kingdom. To put it in perspective, species of fungi outnumber plants by a ratio of 6:1. At least.

During a talk at the Telluride Mushroom Festival in 2011, taxonomical whiz kid Danny Newman suggested that there are 5.1 million species of fungi, not 1.5. The assembled crowd of mycologists, hippies, and nature freaks groaned and booed in response to this daunting pronouncement, but Newman is not alone in his assessment of the profound diversity of Kingdom Fungi.

However, only about 100,000-200,000 species of fungus produce mushrooms; two phyla in Kingdom Fungi are the culprits: Basidiomycota and Ascomycota. Commonly called the club and cup fungi respectively, these two subdivisions of species use mushrooms to reproduce. The long and short of it is that fungi are everywhere, and we do not know much about them compared to other life forms on the planet.

Concluding Thoughts (For Now)

In the second half of this post, I will explore the history of mushroom taxonomy and how it is that we have come to classify fungi and mushrooms in different genera and species, and I will also explain some of the ways in which fungal organisms establish and maintain balance within the ecosystems they inhabit. Rest assured, they’re marvelous creatures with diverse lifestyles and habits, and observing them in culture and in the wild is a profound opportunity to learn new, weird things about life itself.

Without fungi, the cycle of death and life would be interrupted and ecosystems would collapse. Dead organic material would remain inert and pile up sky-high, rather than cycling back into the food web. Vital sustenance shared between species would be static without the fungal highway that delivers nutrients to plants, leading to a decline in biodiversity and food web stability.

Fungi serve as a conduit between species, constantly restoring balance between competing entities. The complexity of the forest, natural meadow and wetlands are a direct result of fungal engineering and networking. It is incumbent upon us as a species to improve our understanding of these vital life support systems so that we do not, through arrogance and carelessness, destroy the organisms that regulate the flow of nutrients and water between living beings on our planet.


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