Numlock Sunday: Krista Langlois on the funky science of bioluminescent mushrooms

Photo by Phoenix Han on Unsplash

By Walt Hickey

Welcome to the Numlock Sunday edition.

This week, I spoke to Krista Langlois who wrote Glowing from Within for bioGraphic. Here’s what I wrote about it:

Fungi have been a relatively understudied kingdom when it comes to bioluminescence, and it’s thought that mushrooms that emit their own light might be more common than currently held. Less than one percent of the 14,000 identified mushroom species — some 125 species — are known to luminesce, but that’s probably an undercount since many mushrooms only luminesce under certain conditions, such as at night. At least 40 new species of bioluminescent fungi have been found in the past decade, and given that some mushrooms only grow underground, it’s also possible we just haven’t seen others do it yet.

We spoke about the mushroom moment we’re in right now, why bioluminescence is so unique and how must we still have to learn about fungi.

Krista can be found at bioGraphic and on BlueSky at @cestmoilanglois.

This interview has been condensed and edited.

Krista, thank you so much for coming on. I really enjoy your story and all the work that you guys do over at bioGraphic.

Thanks, Walt. I’m glad you enjoyed it, and we appreciate you reading and getting the word out.

I think that bioluminescence is just a deeply cool thing, and you covered a part of it that I hadn’t really considered: mushrooms and what makes them interesting and sometimes bioluminescent. Just backing out a little bit, what got you interested in bioluminescence in general and fungi in particular?

I grew up in New England and have been chasing fireflies and catching them since the time I was a kid. Then, in my 20s, I had some bioluminescence in the ocean experiences, and so it’s always been one of those things that is absolutely enchanting.

But as a writer and a journalist, I think the first time I really turned to bioluminescence, I was editing for bioGraphic. I don’t know what year it was off the top of my head, but I would say it was probably around 2021 or 2022 or so. I edited a story about firefly conservation and firefly tourism by the writer Joshua Sokol, and it tapped into this whole thing that people just love bioluminescence. It is this gateway to wonder and to caring about the natural world for a lot of people, and firefly tourism is really increasing.

I worked with him on that story, and I’ve also always loved the mushrooms. I have a tome in my bookshelf that I’ve had for decades called Mushrooms Demystified, and it’s probably more than a thousand pages. I love foraging for mushrooms and just like taking pictures of them, and I’ve always found them really cool. I think that general public interest in mushrooms has been growing over the past five years or so, too. So bioluminescence and mushrooms coming together is this convergence of fascinating, awe-inspiring topics for me.

I can’t say that I was seeking out stories about this. The story is something that we call at bioGraphic a “spotlight.” The way that it starts is our art director goes through all of these really stunning nature photos from all over the world and some different photographers. If they find one that just really stands out and that begs the question of “what on earth is happening in this photo,” he, our art director, will license the photo and set one of us journalists, editors loose on it to write about it.

So I saw this photograph first that our art director had picked out, and it is just some mushrooms that appear to be lit by the sun. They got this beautiful golden glow. And yeah, I just started looking into what species of mushroom this is and digging around and trying to ask questions about it, and that’s what led to this story.

It’s really cool to hear all about the history of mushrooms and glowing mushrooms, going back all the way to Aristotle. You covered a rather recent study in there from 2024, about a very specific new discovery of these mushrooms. To your point earlier, it does seem like fungi’s really having a moment. It really does seem like there’s been a lot more scholarship, or at least scholarship breaking through the mainstream, about the somewhat undercover class of species.

Yeah, absolutely. It’s really seeping into popular culture as well. As a fellow millennial, you probably remember in the maybe like late 2000s, early 2010s, owls were just on all kinds of designs and shirts and handbags. It was like owls everywhere, and now I feel like it’s mushrooms. Mushrooms are the new hot thing.

Do you want to talk a little bit about why this is a little bit undercover? I thought that there were some really interesting things about mushrooms that you wrote, like what made them harder to notice being bioluminescent than perhaps ocean life or something a little bit more obvious, like a firefly.

Totally, so there are 14,000 identified species of mushrooms, but there are probably many, many more. There are hundreds of thousands of fungi. Even just non-bioluminescence in mushrooms, there’s just so much about mushrooms that has been understudied. People are just starting to study now and are starting to identify the full breadth of biodiversity in the fungal kingdom. Some of these, only 125 so far, have been identified as bioluminescent fungal species. Some of these only glow at night, not during the day, which begs the question, “Do they have, like, some circadian clock? How does this fungus know that it’s dark outside?” Photoreceptors? I have no idea.

So some of them only glow at night. Some of them, if you’re walking through the woods at night, you could see a glowing mushroom with the naked eye, so that’s fairly obvious. But some of them only glow via their underground mycelia, not their above-ground fruiting bodies, so those ones are not immediately visible. You’d have to really dig one out of the ground and study it to know that that one glows.

Others do glow above ground, but their glow is so faint that it’s not necessarily visible to the naked eye. Last year, when the aurora borealis swooped south. I was at my home (I was living in Colorado at the time) and I ran outside. I was getting all these notifications on my phone, and I ran outside. I was like, “Oh, yeah, I can kinda see a glow in the sky.” But then I looked at it through my iPhone camera, and it was, like, “pow!” It’s the same thing with bioluminescence and mushrooms. It’s very faint to the naked eye, but if you look at it through a camera or something like that, especially a nice camera with a long exposure, then you can really see it.

All of these things make it hard to know how many species of glowing mushrooms there are out there.

I love just how mysterious this stuff still is. It’s always fun to read about a frontier of science, where we don’t actually know what’s going on here. The range of theories that scientists have for simply why exactly they are doing this is deeply, deeply interesting in its range and in its possibilities. You wrote about a couple of different theories about what it was. Do you want to talk about those?

Sure, and I should be clear that it’s not necessarily that all mushrooms glow for one particular reason. There are a lot of different theories about what that reason is. There’s just so much diversity among mushrooms that some might glow for one reason and some might glow for a totally different reason. It’s all just theories at this point. Although there has been some peer-reviewed research that shows that the above-ground fruiting bodies, when they glow, attract beetles and flies and these other insects that carry fungal spores to help it reproduce in the same way that bees might carry pollen to help a flower reproduce. So that’s one reason that some mushrooms might glow.

They might also attract spiders and other predators that eat fungivores — bugs that would eat the fungi, and to the fungi’s detriment. The spider that’s attracted to the glow perches on top of the mushroom and eats these other bugs. Maybe it’s like a protective measure for those ones. Or maybe it’s just a metabolic byproduct and has no purpose whatsoever. But this one particular species that I wrote about in this story, called Mycena crocata, releases its spores to the wind, so it doesn’t need any help from insects to reproduce.

So, I mean, who knows why it glows? Nobody really, nobody knows for sure.

It’s so intriguing. It’s great. Nothing quite like mysterious mushrooms making strange light to really get the motor going.

Yeah, totally. One of the most fascinating things is that people in Indonesia and India have known about these for centuries, if not millennia, and used these to find their way through dark forests, which I just thought was so cool.

I really dig that. That’s great. I just want to take one second and throw it to you to talk a little bit about bioGraphic. I really love the work that you guys do. Obviously, anytime that there’s a fun number in it, I always try to feature it. Even the photography-related stuff that you’ve done, you had one about a very slow speed chase in Hawaii a few months ago that I’ll link up that I really, really loved. Do you want to just talk a little bit about what the mission over at bioGraphic is and how people can follow y’all’s work there?

Yeah, for sure. I will also say that as a longtime serious journalist, I love doing these little photography-driven spotlights that just focus on awe and wonder and the natural world and interesting things. They’re just so fun to write.

So, bioGraphic is an independent, non-profit online publication that covers biodiversity and conservation around the world. We do a mix of feature stories, immersive features that have video and really good photography embedded in them, these shorter spotlight-driven things and shorter news stories. We do a big mix. We feature stories from all over the world, and the main thing is that they are about some wild animal or plant or fungi or place or ecosystem.

We don’t do stories about domesticated animals. We don’t do stories that are about climate change broadly. That’s obviously a super important thing if you care about the environment, but there are so many outlets that are dedicated to covering climate change and climate justice. We really focus on the biodiversity crisis because plants and animals are really cool, and they don’t get quite as much serious coverage. They are so vital to everything on this planet, even if they aren’t vital to our own survival. I love working on stories about animals that don’t “matter’ in that way, but that just are a source of awe and wonder. I think I’ve repeated those words probably 12 times in this short phone call.

They’re good words.

We just did a story about Alabama sturgeon, and I just love the writer. Hanna Nordhaus had this paragraph at the end that was like, “Weah, they have no value to us. We don’t need them for, like, cleaner rivers. We don’t need them for any medical advances. They’re not ecosystem engineers. They just glide along these river bottoms as they have for millions of years, and that’s enough.” So we get to tell those kinds of stories, which I think is pretty unique and cool.

Yeah, I really dig what you guys do. I encounter many other places on the internet that talk a lot about natural resources. The inherent implication of a lot of that stuff is, “we need this for a thing.” We need to have fish stocks. We need to have lumber. I just really love your guys’ stuff because awe and wonder are not wrong words.

I really appreciate it. Where can folks find you in particular?

I am @cestmoilanglois on Blue Sky.