TERRY GROSS, HOST:
This is FRESH AIR. I'm Terry Gross. When I think mushrooms, I think mmm, stir-fried with dinner. When my guest Nicholas Money thinks mushrooms, he thinks about fungal sex organs that are the most wondrous inventions of the last billion years of evolutionary history on Earth.
Money is an expert on mushrooms and other fungi, including the molds you don't want growing in your home. He's a professor of botany at Miami University in Ohio and the author of the new book "Mushroom." His other books include "The Triumph of the Fungi: A Rotten History" and "Carpet Monsters and Killer Spores."
Nicholas Money, welcome to FRESH AIR. Mushrooms sometimes grow in places where you really don't want to see them. My worst example of that is the mushrooms that were once growing on my kitchen ceiling in a rented apartment. I woke up one day, and I thought: it can't be.
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GROSS: It can't be that my ceiling has mushrooms on it. But upon closer examination, they were definitely mushrooms. I think there was like a leak that had gone undetected and, you know, like water had been seeping, and it was just - it was a very surreal experience.
So what are some of the most inappropriate places you've seen mushrooms?
NICHOLAS MONEY: I rented an apartment years ago in New Haven, and there were mushrooms there that were growing, actually these were cup fungi, large things that were growing around the wooden surround of the bathtub. And - absolutely revolting. So for even somebody that loves the fungi, this was really quite disconcerting.
But far worse than that is a photograph that I've seen of a mushroom, an ink cap mushroom, actually growing in the throat of a patient. So this was actually photographed in some very unfortunate individual whose immune system was really crashing, and actually a mushroom growing in that location is something that none of us want to experience.
GROSS: Why would mushrooms be growing indoors, like in your bathroom or on my kitchen ceiling?
MONEY: Fungi grow on a multitude of different substrates, a multitude of different food sources. And so in our homes, if there are areas of damp wood, flooring, carpeting, drywall - you name it - fungi are going to grow there if those food sources become damp. And because the spores of fungi are everywhere. I mean, every breath that we take from first breath to last gasp, we're inhaling fungal spores. And so they're always available. They're always in the air ready to exploit, to them, useful opportunities to grow and reproduce.
GROSS: Now, you describe mushrooms as fungal sex organs, and they have a very weird way of reproducing. Now, you've taken high-speed video of mushrooms releasing their spores. So - it's high-speed video, so that when it's played back, it slows, it visually slows down the process, and we could actually see what's happening, and you were able to calculate the speed that the spores are being released.
So tell us what you learned from these high-speed videos, and maybe you could describe what one or two of them looks like.
MONEY: Well, it's been known for a long time, over a century, that mushrooms release astonishing numbers of spores. You can actually see them if you put a flashlight beneath a mushroom in the woods at night, and you can see these clouds of spores, this dust being released from the bottom of the cap.
So, individual mushrooms can release as many as 30,000 spores a second - absolutely astonishing - and billions of spores in a single day. But the process of spore release from the gills of the mushroom...
GROSS: Wait, what are the gills? Let's...
MONEY: So the gills, if we look underneath the cap of a mushroom, there's a number of different arrangements of the fertile surface in this sex organ that we're going to see. So in many cases we see gills. In the case of boletes and a number of other different groups of mushrooms, there are tiny tubes beneath the cap.
GROSS: So what did you see?
MONEY: So the mechanism in mushrooms involves the movement of tiny droplets of fluid, so these droplets of fluid are about the same size of the spore, and they condense on the spore surface under wet conditions, and then they coalesce, they move together, they jump together very, very swiftly.
This is on a timescale of millionths of a second. And it's that very fast movement in the center of mass of the structure that kicks it into the air. So it's this microscopic leap that occurs as the spores jump from the gill surfaces. It really is absolutely extraordinary.
If we scale this up to human dimensions, these spores - or if we were jumping off gills, we'd be moving at 500 times the speed of sound to really match the prowess, the elegance of these fungi.
GROSS: A mushroom that seems like a particularly oddity - its name describes it. It's called the phallus impudicus, and it's a penis-shaped mushroom that really smells foul. What sets this mushroom apart, and why does it smell so bad?
MONEY: There's a number of these phallic, foul-smelling mushrooms that we find particularly in tropical ecosystems, but they do grow in the eastern United States and elsewhere. And these are mushrooms that have actually given up this mechanism of spore discharge from gill surfaces, and we're talking about giving up over the course of a long period of evolutionary history.
And they've done so in favor of dispersing their spores by using insects to actually suck up the spore mass, this stinking spore mass. And then as the insects fly away, eventually they deposit the spores far from the parent mushroom.
So it's a completely different mechanism of dispersal, but it's one that we see quite frequently among the mushrooms. The phallic shape actually makes sense just in terms of actually casting this, carrying this stinking spore mass into the air. I mean, the mushroom has to achieve this erection from a buried egg. And then this thing will, you know, be up to five-six inches long and attract slugs and snails and flies, actually a lot of other kinds of flying insects, towards this horrible mass of spores.
GROSS: So it's the smell that attracts the insects? What smells foul to us attracts them?
MONEY: Yeah, these mushrooms actually produce a compound called cadaverine and other kinds of foul-smelling chemicals that actually seem to mimic the smells released from decaying corpses in the forest. And so the kinds of insects that they attract are those that would otherwise perhaps be visiting a dead squirrel or something like that.
GROSS: So we've been talking about, you know, mushrooms as really unusual fungi. We eat mushrooms, and most of the mushrooms in the world are not ones that we eat - some of them could kill us, but, you know, the right mushrooms, the really edible ones, are delicious.
But when I think of them as being a fungus, it kind of is creepy to think that you're dining on a fungus. So what is it that transforms this fungus into something, you know, that's like, yummy and digestible? Are you, like, ingesting fungus? Is it a different product once it's picked and cooked?
MONEY: No, I mean, it really is the same thing. It's just that it's a species that we've cultivated often or perhaps something that we collected in the woods that we choose to eat. But I don't think there's any getting away from the fact that one is actually eating a fungus when you eat a mushroom. The same goes for eating a truffle. It's still fungal.
GROSS: So what makes certain mushrooms hallucinogenic?
MONEY: So there are a number of species of mushrooms that contain alkaloids that - these are chemicals that interact with our nervous systems in very, very specific ways. So the fly agaric mushroom, this iconic thing with the red cap and the white spots, that contains a couple of different hallucinogenic compounds that apparently give one the sensation of flying. That's one of the sensations that's reported by people that enjoy fly agaric mushrooms.
And there are other mushrooms, these are species of Psilocybe and some related things, and they contain compounds that actually mimic, they look a lot like - chemically they're almost indistinguishable from serotonin, and they really play havoc with our nervous systems, and they affect the way that our neocortex operates. And they're responsible for a whole range of different hallucinations.
GROSS: Now, you say that there are current research trials on the possible medical uses of psilocybin. What are they investigating?
MONEY: There have been some really, really interesting studies out of Johns Hopkins in the last few years, where patients have been given specific doses of - quite low doses of psilocybin in a clinical setting and then monitored there, by the researchers.
And one of the things that was interesting about those studies is that - so these people are going on mushroom trips in the lab setting, and they describe those experiences. Months later, in the follow-up studies, they say that these hallucinations, the experiences that they had under the influence of the mushrooms, are among the most profoundly moving experiences of their lives - both positively and negatively - as important, perhaps, as falling in love, a feeling like falling in love for the first time; the birth of a child.
GROSS: So what are researchers at Johns Hopkins hoping to be able to use psilocybin for?
MONEY: One thing that the researchers at Johns Hopkins are looking at now is the use of these magic mushrooms, or rather these hallucinogenic compounds, to actually improve the quality of life for patients suffering from terminal diseases, since it really seems to be, for perhaps the majority of people that actually take these compounds, that it's actually an uplifting experience rather than a negative one.
And so there really might be some very - these could be used in a therapeutic setting and perhaps be very powerful agents in the future.
GROSS: If you're just joining us, my guest is Nicholas Money, he is an expert on mushrooms and other fungi, including mold. His new book is called "Mushroom." Let's take a short break here, and then we'll talk some more. This is FRESH AIR.
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GROSS: If you're just joining us, my guest is Nicholas Money, he is the author of the book "Mushroom," and he is an expert on mushrooms, molds and other fungi. One of his earlier books is called "Carpet Monsters and Killer Spores: A Natural History of Toxic Mold."
I'd like to talk with you a little bit about toxic mold. First of all, you know, we've been talking about mushrooms. Are killer spores related to mushrooms?
MONEY: Well, there are hundreds of thousands of different species of fungi. We've only actually described 70-odd thousand species. Most of the fungi are microscopic things that never produce anything as large as a mushroom. So we might refer to these as molds. There are other technical names for these fungi, but yeah, most of the things are never going to produce a mushroom.
GROSS: So your title is "Carpet Monsters and Killer Spores." What do you mean by carpet monster?
MONEY: Well, fungi will grow anywhere that a suitable food source is available, and carpets actually make a pretty good dining experience for a number of different species of fungi if they become wet.
GROSS: The way we live now, with the new kinds of materials that we live with, have we broadened or decreased the food that fungi can feed on indoors?
MONEY: Oh, we're always broadening the range of opportunities for the fungi. I mean, they're going to thrive and outlive us by an eternity. Fungi can grow on almost any substrate, any kind of material. There are some famous cases of fungi growing in all kinds of unusual situations, growing on the bloom on camera lenses, for example.
There's enough nutritional resources on a camera lens to support the growth of a fungal colony. Fungi have been found growing within fuel lines in airplanes and so forth. So no, there really is no limit to their nutritional flexibility.
GROSS: Now, you write that invisible monsters in the carpet came close to asphyxiating you when you were a child growing up in England because you had asthma. When did you find out what the cause was?
MONEY: That's right. So I grew up in England in the 1960s, and I was quite profoundly asthmatic as a kid; it's something, thankfully, that I've grown out of to a large degree in adulthood.
But I'm not sure we could ever prove that fungi were the cause of my allergies, but I remember that my mother removed the carpet from my bedroom and went to rather extraordinary lengths to try and sort of create this clean living space in which, you know, I wouldn't suffer from these asthma attacks. But it's rather ironic, then, having suffered as an infant from probable exposure to allergenic fungal spores, that I then spent, you know, the next many decades of my life studying fungi.
GROSS: Now, you also describe yourself as a hypochondriac, so I think...
MONEY: Oh, absolutely.
GROSS: A hypochondriac with allergies and asthma studying funguses and molds, it's not necessarily a great combination.
MONEY: I actually - I met a therapist - I met a therapist...
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MONEY: I engaged in some therapy 20 years ago or so...
GROSS: Ran into a therapist...
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MONEY: And he actually pointed this out, and it came to me as a profound revelation. I'd never made this connection. It's like this guy that's such a hypochondriac and yet, you know, studies death and mold and decay and is really just immersed in the study of decomposition.
GROSS: Well, I think it's often true that what repulses us also attracts us, that there's this kind of ugly beauty thing.
MONEY: Yeah, that's probably better therapy there than I received 20 years ago.
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MONEY: So in one of your books, you mention your revulsion for fungi that grow on humans. Have you seen that, I mean outside of like athlete's foot?
I've seen that on myself. I had an awful outbreak of jock itch when I was a graduate student working in a lab where we were just really immersed in fungal spores. They were everywhere. I think everybody in the lab got some kind of skin infection. So that was rather unpleasant seeing this sort of pinkish circle expanding, ever-expanding over my - yes. I don't know how we do that.
GROSS: How do you protect yourself when you're doing that kind of research?
MONEY: Fungi usually aren't a threat to researchers. There are a few species that actually, you know, are pathogenic things that really do cause disease, and so we work in controlled environments with, they're called laminar airflow cabinets. These are sort of fume hoods in which the air is purified, and so we're not really exposed to fungal spores.
But, I mean, the important thing to recognize is that fungi are everywhere, and their spores are everywhere. And worship your immune system as long as it operates effectively because they're keeping fungi at bay 24/7.
GROSS: So some tasty cheeses have mold growing around them. Is it bad to eat that mold?
MONEY: No, no, that's the delicious part of the cheese, if you think about a number of, many of the soft cheeses from France, and the rind on the cheese, absolutely that's edible. But maybe you don't want to think about the fact that you're eating these fungal colonies, that - or eating the white part, that rind is composed of hundreds of thousands, millions of individual filaments that's produced by the fungus that then actually provides a lot of the flavor to the cheese. But no, no, that's edible.
And then if you think about blue cheeses, too, blue cheeses, the little pockets within blue cheese, Stilton and other kinds of blue cheeses, those are actually shot through with fungal colonies, and there you've actually got spores being produced by the fungus that are being actually shed into that - those little pockets.
So it gives this wonderful flavor to the cheese, but perhaps people like yourself don't want to consider that you are eating sort of active fungi.
GROSS: OK, now say you end up eating some bread with a little mold on it. How bad is that?
MONEY: I don't think - that's actually not - again, that's not going to be a significant, it's not a problem to actually eat moldy bread, but it is rather unpleasant, and that's certainly something that I find revolting. I'm quite - I go on these jihads. My wife dislikes the way that I keep the fridge so scrupulously clean, but I think I'm - I really don't like the idea of eating food that's contaminated with fungi or bacteria.
GROSS: So we've established that, you know, some mushrooms are beautiful, some are kind of repulsive-looking, and some are really tasty, and some are really poisonous. What function, outside of the ones that we eat, what function do they serve in the world?
MONEY: Life on land is completely dependent on the activities of fungi. So, some of these are the mushroom-forming fungi, but all these microscopic species, too, that don't produce these larger sex organs. Fungi are primary agents of decomposition. If it weren't for their activities, we'd have, you know, dead wood and plant material everywhere. We'd have animal feces that would build up in vast quantities.
And so fungi are contributing to all of the planet's major nutrient cycles, particularly the carbon cycle, in breaking down very complex materials within plant tissues, wood for example, breaking that down into sugars that they then burn through their metabolic activities.
So they're very, very important in nutrient cycling. They also support the activities of plants through what are called mycorrhizal relationships, that fungi and mushroom-forming fungi hook into the roots of forest trees and shrubs and support the activities, the lives of all of the plants in a forest - grasslands, too. Grasslands are dependent on the activities of other kinds of mycorrhizal fungi. So really life on Earth as we see it now would be inconceivable without the activities of fungi. They're an absolutely critical part of the biosphere.
GROSS: Well, Nicholas Money, I want to thank you so much for talking with us.
MONEY: Thank you so much.
GROSS: Nicholas Money is the author of the new book "Mushroom." On our website, you can read an excerpt of the book, watch his high-speed video of mushroom spores dispersing and see a picture of the phallus impudicus, the penis-shaped mushroom. That's freshair.npr.org.
Money is a professor of botany at Miami University in Ohio. I'm Terry Gross, and this is FRESH AIR.