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LESLEY YORKE: Good afternoon. And welcome to an interactive conversation with faculty. I'm Lesley Yorke. And with me today is Kathie Hodge, a faculty member who focuses on fungi. Welcome, Kathie.
KATHIE HODGE: Hi, Lesley.
LESLEY YORKE: It is great to have you here and great to be in Mann Library's gallery, surrounded by an exhibit that you organized about fungi.
KATHIE HODGE: I know. Isn't it great? I love it.
LESLEY YORKE: It's beautiful. And there's some creepy crawlies in here. And there's some beautiful pictures. And I'm sure there are a lot of stories to tell.
KATHIE HODGE: They're all beautiful to me.
LESLEY YORKE: So tell me what brought you to this place?
KATHIE HODGE: Oh, that's a long story. How far back can we go?
LESLEY YORKE: You know, good stories start with long ago and far away.
KATHIE HODGE: OK, so when I was a little girl, I used to look at everything small with a hand lens that my father gave me. And so I spent a lot of summers crawling around in the undergrowth looking at tiny things. And there was this one thing that I found that looked like a little orange finger.
And it was attached. If you yanked it up, it was attached to a brown bullet. And it was a baffling thing. I couldn't figure it out for the longest time. But it turned out that the bullet was actually the pupa of a moth.
LESLEY YORKE: So that stage between caterpillar and flying moth.
KATHIE HODGE: That's right. So it was a bullet-- it was a busy changing inside that little bullet-shaped thing. And the orange finger sticking up was actually a fungus that only eats moths. It was killing that little moth.
And so as a child I got very fascinated by that thing. And I forgot about it for many years until I got to college and took courses in everything small and got really inspired by fungi from my college professor.
LESLEY YORKE: So you are now a fifth-generation mycologist at Cornell. That means four other generations of people who study mushrooms and yeast and mold have preceded you.
KATHIE HODGE: That's right.
LESLEY YORKE: They created a collection which is called--
KATHIE HODGE: It's the Cornell Plant Pathology Herbarium. And it's a big collection. We have hundreds of thousands of samples of fungi preserved over the last 125 years. It's kind of a storehouse of fungal biodiversity.
LESLEY YORKE: Hmm. And so what do you use the herbarium for?
KATHIE HODGE: Well, I mean, it's a storehouse of biodiversity. So it documents fungi in the world over the last century or so. And we act as kind of a lending library. So--
LESLEY YORKE: So you can dial up and get mushrooms in the mail?
KATHIE HODGE: Kind of. If you're a scientist, you can. And we don't-- they're all dead and preserved. But we-- they're really important scientifically. Some of them are the first of their kind ever described. Actually about 7,000 of them are those.
LESLEY YORKE: So when I was looking at the exhibit earlier, I saw that there are index cards with that beautiful sort of calligraphy handwriting and fading ink. How do you make a collection like this available to a world that is global?
KATHIE HODGE: Yeah. Well that's a good question. And that's a very frustrating thing to do. We've been doing that over the last three years, bringing our information about our collections into the modern age by actually digitizing all the information about the specimens. And it does-- it's very challenging to take handwriting. And somebody has to type that in.
LESLEY YORKE: Oh my goodness.
KATHIE HODGE: But the result of that is that we can look at our collection data in a new way. So we used to have to leaf through index catalog cards-- very tedious. But now if you ask me what fungi fruited on July 1 over the last 100 years, I can tell you. It's very powerful.
LESLEY YORKE: That is powerful. And I mean, so data and information is really powerful. But one of the things that you told me is that the reason that you love mushrooms so much is that they have overlooked stories-- sorry, mushrooms, fungi, yeast, molds-- their stories are overlooked. And tell me how you help to tell those stories now.
KATHIE HODGE: I guess I feel like I'm kind of a champion of fungi. I think they're so fascinating. And it's amazing to me that people don't know much about them. So through the herbarium work and some outreach I do, but also the Cornell Mushroom Blog, we like to tell the stories that fungi can't tell on their own.
LESLEY YORKE: So I-- you did tell me a story about a Cornellian who actually ate a deadly mushroom and survived.
KATHIE HODGE: He survived.
LESLEY YORKE: He did. What kind of mushroom was that?
KATHIE HODGE: It's a mushroom called the destroying angel.
LESLEY YORKE: The destroying angel.
KATHIE HODGE: Really, don't eat anything called the destroying angel.
LESLEY YORKE: Yeah, but out in the wild how would I know that it was a destroying angel?
KATHIE HODGE: Well, that's the problem.
LESLEY YORKE: Yeah. So-- but back to storytelling with The Mushroom Blog. I understand that you and your students both do some posting. And your most recent post--
KATHIE HODGE: --is about fungi that grew on the poop of extinct woolly mammoths.
LESLEY YORKE: That extinct woolly mammoths poop mushrooms--
KATHIE HODGE: A compelling story already, isn't it?
LESLEY YORKE: A compelling story already. But how do you know that that's what you're looking at? And where do you find this?
KATHIE HODGE: Well, one of my students wrote this post. It's really fine. So it's on The Mushroom Blog right now. But the basics are that if you want to know where woolly mammoths were in the world-- it's hard to find a woolly mammoth even though they're very large.
But they left behind a lot of poo. However the poo tends to turn into something like soil. So we can find where the poo was by finding the spores of the fungi that live in the poo. Am I just embarrassing myself here?
LESLEY YORKE: You are not embarrassing yourself. But I mean, how do you know when you're seeing a spore? I understand they're smaller than we can see with the naked eye.
KATHIE HODGE: Yeah. Fungal spores are very small. And you can probably fit a hundred of them in a millimeter. So you need a microscope to find them.
LESLEY YORKE: And do you take one microscope out into the field?
KATHIE HODGE: You can.
LESLEY YORKE: Or you bring the poo back to your lab?
KATHIE HODGE: Yeah, more often. Yeah, mycologists are notorious for studying poo for some reason.
LESLEY YORKE: Well, you know it makes for a good story.
KATHIE HODGE: I guess so.
LESLEY YORKE: Yes. So I understand that there are fungus who have a particular attraction to other kinds of insects. And we are currently in the midst of the cicada invasion on the eastern coast here.
KATHIE HODGE: Yeah.
LESLEY YORKE: Are there any fungi who like them in particular?
KATHIE HODGE: How did you know?
LESLEY YORKE: Because you told me. But it's a great story.
KATHIE HODGE: Well, another student of mine wrote a fine post on the Cornell Mushroom Blog about fungi that kill cicadas. But they kill cicadas in a really creative kind of way. They don't just kill them.
They actually eat their butts off. And then-- so then you have live cicadas flying around that have no butt. But trickling out of where their butt should be are spores that can infect other cicadas.
LESLEY YORKE: OK, so we have cicadas, buttless cicadas flying around, dribbling spores. And they fall on other cicadas?
KATHIE HODGE: So then the more cicadas get sick. Later in the season, the cicadas that get sick toward the end of the season, they don't do the dribbly butt thing. They instead develop spores that fall to the soil. And those spores wait there for 17 years until the next batch of cicadas emerges. And somehow they sense them and get them.
LESLEY YORKE: It is amazing to me. And one of the things that you had talked about was just how the students that you love to work with best are the ones who just love nature, who just want to figure things out. So I know that you teach two courses in this area, and one on mushrooms and one on fungi. Oh my gosh, you've got to help me here.
KATHIE HODGE: Well, it's called Medical and Veterinary Mycology. So it's fungal diseases of people and animals. So everything from yeast infections, athlete's foot to fungi that can eat your face off basically.
And I know it's disgusting, horribly disgusting. There's something compelling about things that are horribly disgusting. But it's important because some of these diseases are quite deadly. And we don't know much about them. My students want to become doctors and veterinarians. So, yeah.
LESLEY YORKE: Wow. That's-- it's mind-boggling. So one of the things that we do in this series of ours is to open up and take some questions from our audience. And some of those questions have come in ahead. And so I'd like to just see what's on our screen here.
KATHIE HODGE: OK, yeah.
LESLEY YORKE: OK.
KATHIE HODGE: No math questions.
LESLEY YORKE: No math questions. Oh. This is interesting. How do fungi help trees?
KATHIE HODGE: How do fungi help trees? Good question. Well, there's some fungi that kill trees. Just want to put that out there.
But underground, most trees that live around us are hooked up underground to a fungal symbiont, a partner. And they're very special partners. They feed each other. So the fungus provides nutrients from the soil that the plant couldn't get on its own.
And the-- and the tree donates some of the nutrients it captures from sunlight to the fungus. And without that relationship, we wouldn't have our modern forests.
LESLEY YORKE: Can you see this network? Is it visible or is it sort of at the microscopic level?
KATHIE HODGE: It's sort of at the microscopic level. But you can see it because many of our fall mushrooms around here are the fruiting bodies of those secret symbioses.
LESLEY YORKE: The secret symbioses?
KATHIE HODGE: Yeah, yeah. So some of the best eating mushrooms-- the chanterelles, the boletes-- those are all tree symbionts.
LESLEY YORKE: That is so cool. But that leads me to another question. And I think-- so when you mentioned fruiting body, it made me think, so do mushrooms have a flower is one of the questions on--
KATHIE HODGE: Flower, do they have a flower? Well, mushrooms are kind of like a flower. They make essentially seeds. The whole function of a mushroom is to make spores, which are like seeds. So yeah, kind of like flowers.
LESLEY YORKE: And-- OK. So there is another question coming in here. This one I think is-- oh, can we go for the gross?
KATHIE HODGE: Oh, I hate gross.
LESLEY YORKE: OK, then I'll go for the serious.
KATHIE HODGE: No. Go for the gross.
LESLEY YORKE: So what eats fungus?
KATHIE HODGE: Oh, lots of things. Well, other fungi for one thing. That's my favorite. Those mycoparasitic fungi are fungi that eat other fungi. And they're kind of awesome too. But also lots of bugs and mites and tiny things in soil.
LESLEY YORKE: Yeah. And people.
KATHIE HODGE: And people.
LESLEY YORKE: So people-- so your mushroom course teaches people about what mushrooms to eat and what mushrooms not to eat.
KATHIE HODGE: Yeah.
LESLEY YORKE: But there are also molds that we eat and molds that we find thoroughly disgusting.
KATHIE HODGE: Yeah, yeah. So like blue cheese is a--
LESLEY YORKE: That's a delicious kind.
KATHIE HODGE: You like blue cheese, right?
LESLEY YORKE: I love blue cheese.
KATHIE HODGE: Yeah, Brie and Camembert are also mold-fermented cheeses.
LESLEY YORKE: They are? On the exterior or on the interior?
KATHIE HODGE: You know that powdery white rind? Well those are fungus spores.
LESLEY YORKE: They're fungus spores?
KATHIE HODGE: Mm, tasty fungus spores.
LESLEY YORKE: Mm, tasty and delicious.
KATHIE HODGE: Yep. But other fungi that you might find in your kitchen are not so friendly. And if you ate them, some of them contain toxins that you probably shouldn't eat. So don't eat moldy food unless it's supposed to be moldy.
LESLEY YORKE: OK. So if mold grows after I purchase it, if it's not already there, then I shouldn't be eating it.
KATHIE HODGE: Yeah.
LESLEY YORKE: OK.
KATHIE HODGE: Let's say, yeah.
LESLEY YORKE: That's it. All right. So I know that you're also fascinated by the everyday molds and fungi that you find, say, in your kitchen and that you're just about to start a study on those. Can you tell me about that?
KATHIE HODGE: Yeah. Actually we're interested in extremophile fungi. So normally you would think extremophiles, you have to go to a deep-sea vent or a thermal spring somewhere to find them, right? But in fact there are extremophiles that live right in our own homes all the time.
LESLEY YORKE: Extremophiles in my home.
KATHIE HODGE: Extremophiles, yes.
LESLEY YORKE: I'm getting very nervous here.
KATHIE HODGE: Those dry places, right? The corner behind the toaster where it's like a desert. But there's crumbs. So there are fungi that live in that environment. And they're not very well known.
LESLEY YORKE: Well, you told me earlier that very few, a very small percentage of fungi are actually identified.
KATHIE HODGE: Yeah.
LESLEY YORKE: What is that percentage?
KATHIE HODGE: Oh. It's like such a shocking number that it's hard to even get my head around it. But it's at least-- at least 9 out of 10 fungi don't even have a name yet.
LESLEY YORKE: Hey speaking of names--
KATHIE HODGE: Yeah.
LESLEY YORKE: Do you have any fungi named for you?
KATHIE HODGE: There's one fungus named after me, yes.
LESLEY YORKE: Yes?
KATHIE HODGE: It's called Peziloma [? Kathie. ?] And my predecessor Dick Korf named it after me. It's a beautiful little cup fungus that lives in streams.
LESLEY YORKE: Streams?
KATHIE HODGE: Yeah.
LESLEY YORKE: I don't know if I've ever seen a mushroom in a stream. But we have a question from somebody that I think is right on target here. So she says, so why do mushrooms grow so fast?
I left for work yesterday. And I had a mushroom-free lawn. But I came home to a big batch of fist-sized mushrooms.
KATHIE HODGE: Ooh, lucky!
LESLEY YORKE: How is that possible?
KATHIE HODGE: Oh, well, they're just fast. They want to fruit while it's wet because mushrooms actually need humidity in the air in order to do the main thing that mushrooms are made for, which is to disperse their spores. So mushrooms that come up in really dry weather have a harder time getting their spores around.
LESLEY YORKE: Well, there you go, Lisa. That's the answer to your question. Another-- ah, this is interesting. So Nancy asked, can fungi help people stay healthy or fight illness?
KATHIE HODGE: Yes, yes. And I'm not--
LESLEY YORKE: Could you give maybe an example or--
KATHIE HODGE: Yeah, well I'm not an herbalist. But there certainly are fungi that are important in herbal medicine. Like, the reishi mushroom has been used for centuries in Asia. And there are a number of others that grow around here like the maitake. I think you told me you like maitake mushrooms.
LESLEY YORKE: I do like maitake mushrooms.
KATHIE HODGE: That one has some medicinal benefits too. So yes, fungi can do that.
LESLEY YORKE: Very cool. So Linda wants to know, are there any fungi, speaking of our earlier conversation, that are symbionts with humans?
KATHIE HODGE: Yeah, that's a really interesting question. We're just starting to find out about that. So in fact, the first papers about the micobiome of humans, the fungi that live inside us or on us, came out just in the last year or so.
But yeah, there's a fungus called malassezia that-- most of us have colonies of malassezia on us on our scalp. Sometimes they act up and cause dandruff. But they're just our constant companions.
LESLEY YORKE: Well, we do know that we're made up of all sorts of other hangers-on in our bodies. Well, Kathie, our time is almost up. But one of the things we do at the end of each of these conversations is to ask a question about, as a teacher, as a mentor, what is it that you hope your students will take from their experiences in the classes that they take with you as they move out into the world?
KATHIE HODGE: Well, I actually in the syllabi from my undergraduate courses, I have a goal. And we talk about the goals at the beginning of the course and agree to them. And that goal is to be able to tell other people convincingly why fungi are cool.
LESLEY YORKE: Kathie, you have convinced me that fungi are cool. Thank you so much for joining us, Kathie. And thank you, too, for your questions and for sharing this conversation with us. We'll look forward to seeing you next time.
Q&A with Kathie Hodge, a faculty member who works with fungi. Kathie is a faculty member in Plant Pathology and Plant-Microbe Biology, and director of the Plant Pathology Herbarium, a collection that documents the diversity of fungi and plant diseases across the globe. She blogs about her work on The Mushroom Blog, which has great photos, engaging stories, and some incredible time lapse videos.
Lesley Yorke will interview Kathie from Mann Library's second floor gallery, where she has curated an exhibit of materials from the Herbarium.