Psychedelic Deer Mushroom (Pluteus americanus)

Good evening, friends,

We just wrapped up another Friends of Fungi weekend at Menla Retreat and Spa in the Catskills. We didn’t find a plethora of edible mushrooms, the results of a dry August, but we did find plenty of interesting fungi in a variety of different forms.

At one point during the morning foray, Shaw came up to me and showed me two little brown mushrooms. The two immediately noticeable characteristics were the blue at the base of the mushrooms and the pinkish brown gills. Today we’ll look at the lesser-known, naturally occurring psychedelic mushroom Pluteus americanus (which we were calling the Psychedelic Deer Mushroom, as Pluteus cervinus is the Deer Mushroom).

Fun Facts

Typically, mushrooms that contain the psychoactive compound psilocybin belong to the genus Psilocybe, but there are a handful of unrelated mushrooms that produce the compound as well.

Interestingly, it is understood that these other genera of fungi developed the ability to produce psilocybin through a horizontal gene transfer — the capability of organisms, particularly fungi, to obtain genes from other fungi that they come into direct contact with in the environment (Reference 2). Pluteus fungi, which inhabit and digest dead wood, share a similar ecological niche with many species of Psilocybe.

The pinkish gills and “free gills” (gills that don’t directly run into the stipe) indicate the genus Pluteus.

The key identifying characteristic for a psilocybin-containing mushroom is blue bruising. The blue bruising is caused by the psychoactive compound psilocybin breaking down and oxidizing into “quinoid psilocyl oligomers” - compounds similar to indigo (Reference 3).

Now, there are other non-psilocybin containing mushrooms, like many boletes, that also bruise blue. This is due to the presence of different chemicals, such as pulvinic acid.

It’s notable that most of the blueing was right at the base of the mushrooms. I couldn’t find any information on how much psilocybin these mushrooms actually contain.

From my understanding, the leading hypothesis for why mushrooms bruise blue is to deter slug consumption. At the Telluride Mushroom Festival, Paul Stamets played a video in which he placed European black slugs in a box with the blue-bruising Wavy Caps (Psilocybe cyanescens) and the Garden Giants (Stropharia rugosoannulata). You can see for yourself which mushrooms the slugs preferred.

Lastly, we could spend all day discussing what happens when humans consume psilocybin (there have been 467 papers published on the compound this year alone). It is actively being researched for potential therapeutic benefits in the treatment of depression, addiction, PTSD, and a variety of other mental afflictions.

The pinkish brown spores landing on the stipe contrast with the bluing feet of the mushroom.

Ecology

The fungus is saprobic and decomposes hardwood trees. It seems to be found on well-decayed hardwoods which suggests that it is a secondary or tertiary decomposer — a fungus that is getting in there after other fungi and organisms have already broken down the wood to a certain extent. The species can be found in eastern North America where it fruits summer through fall.

There are a few different psilocybin-containing Pluteus species, and to be confident in the identification I would have to throw this little guy under the microscope to observe the “pileipellis”, “pleurocystidia”, and “cheilocystidia”. We all know P. americanus has clavate cheilocystidia and pleurocystidia with well-developed apical prongs, that’s day one stuff, but we still have to make sure. Anyway, I didn’t go home with the mushrooms, but we did dehydrate them for sequencing and to potentially culture them.

Pluteus salicinus is the European species, Pluteus saupei and Pluteus cyanopus are both found in eastern North America (seldomly), and Pluteus phaeocyanopus is found in western North America.

Shaw and I standing over the well-decayed wood where he found these mushrooms. Photo credit: Gabriela D’Elia

Speaking of psychedelic mushrooms in the Catskills, an intrepid group of four found themselves on the receiving end of a “debilitating high” after they overindulged on psilocybin mushrooms (the cultivated variety are typically Psilocybe cubensis). You start the day thinking you’re going to connect with nature and have a profound experience with your buddies, next you thing you know you’re nonverbal in the fetal position and you’ve made international news. Not how you draw up your Saturday of Labor Day Weekend.

Some Other Weekend Finds

Ophiocordyceps stylophora

An entomopathogenic (insect-parasitizing) fungus growing from the larva of a beetle. Soon to be the feature of a forthcoming Mushroom Monday...

Ascocoryne sp.

A small, purple ascomycete typically found in the fall.

Calycina citrina

Yellow Fairy Cups on rotting hardwood. Another fall ascomycete, this one has a cosmopolitan distribution across the globe.

Another Impossibly Small Ascomycete on a Leaf Petiole

Last week I posted a similar-looking, predominantly yellow species from the COMA foray which the president of the New York Mycological Society, Ethan Crenson, identified that as Hymenoscyphus epiphyllus. These aren’t the same color, but are similar in shape and size.

I have a memorial service/family reunion this upcoming weekend in eastern France, and my brother and I are going to spend a few days in Alsace after the memorial. We’re going to get out in the woods (as the older brother I will be enacting the “whatever I say goes” itinerary) and see what mushrooms are growing in this mycophilic region of the world, which I’ll then write about in next week’s newsletter.

They’ve had rain over there, and we’re finally starting to get rain in the northeast, so let’s go ahead and have a fruitful fungal fall.

Au revoir,

Aubrey

References:

1. Kuo, M. (2016, June). Pluteus americanus. Retrieved from the MushroomExpert.Com Web site: http://www.mushroomexpert.com/pluteus_americanus.html

2. Reynolds HT, Vijayakumar V, Gluck-Thaler E, Korotkin HB, Matheny PB, Slot JC. Horizontal gene cluster transfer increased hallucinogenic mushroom diversity. Evol Lett. 2018 Feb 27;2(2):88-101. doi: 10.1002/evl3.42. PMID: 30283667; PMCID: PMC6121855.

3. Lenz C, Wick J, Braga D, García-Altares M, Lackner G, Hertweck C, Gressler M, Hoffmeister D. Injury-Triggered Blueing Reactions of Psilocybe "Magic" Mushrooms. Angew Chem Int Ed Engl. 2020 Jan 20;59(4):1450-1454. doi: 10.1002/anie.201910175. Epub 2019 Dec 4. PMID: 31725937; PMCID: PMC7004109.

4. https://mushroomobserver.org/observations/map?q%5Bmodel%5D=Observation&q%5Bnames%5D%5Binclude_subtaxa%5D=true&q%5Bnames%5D%5Binclude_synonyms%5D=true&q%5Bnames%5D%5Blookup%5D%5B%5D=pluteus+americanus

5. https://www.inaturalist.org/observations/312058203

6. NYMS Pluteus Guide, Jakob & Rozanoff, https://docs.google.com/presentation/d/e/2PACX-1vQgOeHvlh6fVBluTnSAdc_cNDbA6NsenlGfu1hN6vOyDuBf01aPomlCzBt_6J0X26jxeByoSy01GEpD/pub?start=false&loop=false&delayms=60000&slide=id.g34a51341c49_0_176