Bryn's Boletes

Smallhold Friend

basket of boletes

Who are you? When was your first mushroom moment/how did you know you wanted to devote your career to mycology?

I am Bryn Dentinger, born and raised in Duluth, MN where I grew up in a family that spent much of its free time in nature; camping, fishing, hunting. Mushrooms were not something my family paid any attention to, but I started to take an interest in high school. I remember a particular day when my mother handed me the Audubon Field Guide to Mushrooms and suggested I try to identify the mushrooms growing in our backyard. I was probably 15 or 16. A whole new world was unveiled to me that day. I discovered the subtle, complex beauty of mushrooms and have been fascinated by them ever since. But I didn’t decide to dedicate my career to mycology until after I graduated from college. I was working in a pharmacology lab in upstate New York (my plan was to pursue a career in neuropharmacology) and learned that pharmacology was not holding my interest. I had flexibility to spend many afternoons looking for mushrooms there. It wasn’t long before I came to the conclusion that I really wanted to dedicate my career to them. So I headed back to Minnesota, where it just happened that the annual NAMA meeting was being held that year, and met my future PhD adviser there. I started graduate school that fall (2001).

bryn in the lab with a microscope

 What are you researching right now and where?

We are wildly curious people! We currently have funding to support to major projects:

  • Attempting to understand the evolution of the fungus-farming ant mutualism (think leaf-cutter ants, which use the leaves to grow a mushroom that is their primary source of nutrition)

  • Investigating:

    • the origin, evolution, and drivers of species formation in porcini mushrooms (family Boletaceae).

    • the source of the mysterious “xiao ren ren,” reportedly caused by eating hallucinogenic boletes in southern China.

  • Studying:

Unidentified Cortinarius sp.

Unidentified Cortinarius sp.

What were you studying in Australia?

One of the great mysteries for us is why there are so many species of porcini mushrooms that are found in all ectomycorrhizal habitats globally (“ectomycorrhizas” are a beneficial symbiosis between some types of fungi -- mostly mushroom-forming fungi -- and the roots of mostly woody plants; this symbiosis dominates the temperate forests of the world and some tropical forests where the trees depend on the water and nutrients that the fungus provides in exchange for sugars the plants generate through photosynthesis).

 Our work is showing that the porcini mushrooms first evolved ~150 million years ago in Gondwana, the land mass that was formed by present day South America, Africa, India, Australia, New Zealand and Antarctica. We’re trying to understand how they managed to get around the world, and to do so we need to sample them from all of their present locations and then reconstruct their relationships using phylogenetic analysis (generating a kind of “family tree” based on DNA sequences). One hypothesis is that they arrived in Asia via the Australasian archipelago after floating on Australia and being deposited on the emerging island of New Guinea as Australia slammed into the Eurasian Plate ~25 million years ago. So I was collecting in northern Queensland in hopes of finding relicts of this ancient event.

Tylopilus sp.

Tylopilus sp.

We hear that you are the expert on boletes, what can you tell us about boletes? Any quirks, personality traits, where can you find them, what do they taste like/how do you cook them?

 First, I would say that there is no single expert that holds all the knowledge on the boletes. Certainly not me! These are mysterious organisms that have long been a source of consternation because they are difficult to fully grasp. So if I have expertise, it is in self-torture (or narcissism?) from my foolish obsession with trying to understand what has been and continues to be utterly confusing to me. Up to now, no one has successfully deduced their relationships and as a result they have suffered from countless taxonomic revisions, none of which have resulted in more clarity. The current trend of naming new genera for only a single or a few species is counterproductive. Once we have a stable phylogeny (which my lab is in the process of generating), then we can start to establish a stable system of naming that will hopefully provide a reliable and practical resource for researchers and enthusiasts, alike.

Boletes (family Boletaceae) are found worldwide, mostly as ectomycorrhizal mutualists with trees (which is why they can’t be cultivated…yet!). Although boletes are typically fleshy mushrooms with caps, stalks, and a layer of narrow, tightly packed vertical tubes that creates a sponge-like layer under the cap, both gilled mushrooms and truffles have evolved multiple times in the group. Unlike the majority of the species in the family (currently at ~2000), the oldest lineage of the family (including the genera Chalciporus and Buchwaldoboletus) appears to not be strictly ectomycorrhizal, but instead has saprotrophic (decomposing) and/or mycoparasitic ecologies. And then there is the odd Pseudoboletus parasiticus, which grows on pigskin puffballs (Scleroderma spp.). A few species are highly poisonous and have caused fatalities in humans (e.g., Satan’s bolete, Rubroboletus satanas), but mostly they are thought to be safe to eat.

In my experience, however, most of them are far from delectable. My favorite is, of course, porcini. There are >50 species of porcini (i.e. species closely related to Boletus edulis) around the world, all of which are probably edible, including a recently discovered truffle in Australia. I like to dry porcini to concentrate their aroma and flavor (which is probably best described as “sweet-nutty”), and then reconstitute them to use in sauces or soups, or pulverize them to use as a dry rub. The texture of fresh boletes, including porcini, tends to get a little soft when cooked, which I don’t like. Raw porcini can also be delicious (in small doses, since raw mushrooms are highly indigestible), with a flavor that is, to me, reminiscent of edamame.

Cruentomycena aff. viscidocruenta.

Cruentomycena aff. viscidocruenta.

Is it true that there is a bolete with psychoactive properties? Tell us more.

We don’t know. There are reports of psychoactive boletes from New Guinea and southern China. This may be a coincidence. The implicated boletes in New Guinea, originally reported in the 1930s as “mushroom madness” in highland communities, were later putatively identified and tested for indolic compounds, i.e., ones related to psilocybin and LSD, but the results were inconclusive. There haven’t been any follow up studies or further documentation of the phenomenon in New Guinea since these studies in the 1970s and it is unclear if there is an actual material basis for the “madness” or what the source may be, boletes or mushrooms or something completely different.

On the other hand, reports of intoxication causing “Lilliputian hallucinations” (seeing “little people”) following consumption of undercooked or improperly prepared boletes occur regularly in southern China. The implicated species is known as Lanmaoa asiatica, but a great deal of confusion and contradictory information surrounds its identity as well as the source of the intoxications. We don’t even know if the reports are connected to a true physiological effect, let alone what causes it. We’re currently working on disentangling this mystery.

 “Lilliputian hallucinations” (seeing “little people”), in this case little people are climbing all over a giant person and holding them down with rope

What about your research into psilocybin-containing fungi was the most surprising finding? Is there a god telling us to trip on mushrooms? What is your opinion on the stoned ape theory?

I think there are two very interesting discoveries about psilocybin that have been made recently. The first is that the genes that encode the enzymes that make psilocybin have been transferred between species -- that’s not normally how traits are inherited. The second is that it appears that the enzymes that make psilocybin have evolved independently. These two observations point to a strong ecological function of psilocybin, but we still don’t know what that is. Intriguingly, evidence that psilocybin functions as an on-demand building block for a chemical chain (which is the source of the blue pigment that forms when the mushrooms are handled) suggests that psilocybin is not directly involved in the function and its psychoactivity in vertebrates may just be a happy accident.

Psilocybin evolved in mushrooms millions of years ago -- our research suggests it first appeared ~68 million years ago -- long before humans evolved (my hypothesis is it evolved in response to mushroom-feeding slugs and snails). Whatever its ecological function, it isn’t to interact with humans. We are phenomenal story tellers, though and the stoned ape “theory” is a story that has captured the imaginations of many. However, there is no scientifically plausible basis for it that doesn’t invoke new forms of evolution that would contradict what we currently understand about it. It’s fun to think about, but it’s just a story of the supernatural. My view of the world doesn’t require supernatural explanations, even when something remains unexplained.

Lanmaoa fragrans.
Lanmaoa fragrans.

What are some remarkable findings/fungi that surprised you in recent years? 

Every time I go out I find something new (or at least that’s what it feels like)! Some of the most notable boletes that stand out include an as-yet undescribed turquoise-blue species from the Congo Basin in Cameroon, a new species of the bizarre genus Spongiforma from Sarawak (Borneo), and a species of Borofutus that I collected (before the genus was described) in a littoral forest in southeastern Vietnam with spores that flash purple in dilute potassium hydroxide.

What parts of the world have the most interesting conditions for discovering fungi that are unique?

 Every part! No kidding, fungi are everywhere and we have only document a tiny fraction of them, so new things lurk around every corner. I guess from my experience collecting, the two places that have stood out are southeast Asia (Vietnam, Borneo) and the Congo Basin (Cameroon).

 What advice do you have for aspiring mycologists? What pitfalls are there?

 Join a local foraging club or reach out to your local mycologist (if you’re lucky enough to have one nearby). Mycologists are very friendly, inclusive people and our communities tend to be tight knit and very welcoming, so don’t be shy! As for pitfalls, I would strongly discourage anyone from trying to forage for food on their own -- that has a strong chance of ending in disaster. The other fair warning I would give is identifying fungi is hard, even for professionals. Many of the features are microscopic, require a lot of interpretation and may be impossible. Instead of trying to identify species, try and recognize the genera.

Pterula sp.


Pterula sp.

Are you more enamored with the science, the adventure, or both?

The science and the adventure are inextricable for me. They enhance each other and neither can really stand on their own for me.

 Who are some professionals you look up to?

 Living or dead? Mycologists of the past have to include Anton de Bary, Reginald Buller, and EJH Corner. Today, I was very inspired by the work of David Hibbett, Tom Bruns, Rytas Vilgalys, Jean-Marc Moncalvo, Roy Halling, Roy Watling, Joe Ammirati, and my own PhD advisor, David McLaughlin. That is just a few names of a long list of people whose work I admire greatly.

Anything else we should know?

I think we’re entering (or have entered) a golden age for mycology, both professionally and socially. Thanks to the “mycoevangelism” of people like Paul Stamets, there is a critical mass of appreciation and awareness of the importance of fungi for our lives, and this is having impacts on my own work. Fungi are going to be critical to a sustainable future, I think more than we really know right now, and we would be remiss to not pay more attention to them.