Big Laughing Gym (Gymnopilus junonius)

Description
Mushroom Identification
Look-Alikes
FAQ
Synonyms

Description

Gymnopilus junonius is a large, orange mushroom commonly found growing on tree stumps, logs, or at the bases of trees. It has a distinct bitter taste and a stem featuring a ring or ring zone. The spore print of this mushroom ranges from orange to brownish-orange. While it is widely distributed across Europe, Australasia, and South America, it does not occur in North America, though some similar-looking species are found there. This species is known to cause brown wood rot, contributing to the decomposition of wood in its natural habitat.

There have been reports suggesting that Gymnopilus junonius contains psilocybin 😵‍💫 in low amounts, though many sources dispute this claim. Hallucinogenic substances may be present in the fruiting bodies, but their concentrations can vary, with higher levels reported in the United States and Japan compared to Europe. It is also possible that the mushroom has been confused with a subspecies or other look-alike species that do have psychoactive effects. In addition to potential psychoactive compounds, Gymnopilus junonius contains bis-noryangonin and hispidin, which are structurally related to alpha-pyrones found in kava. Neurotoxins known as oligoisoprenoids have also been identified in this species.

In Uruguay 🇺🇾, Gymnopilus junonius is considered edible and is among the most consumed mushrooms. To make it palatable, it must be boiled several times to remove its inherent bitter taste. It is often used in sandwiches, paired with beef, bacon, and other ingredients, making it a popular local delicacy.

Historically, this species was first described by Swedish mycologist Elias Magnus Fries in 1821, who named it Agaricus junonius. It was later reclassified to its current genus in 1960 by British mycologist Peter Darbishire Orton. The name Gymnopilus derives from the Greek words "gymn-" meaning naked and "-pilus" meaning cap, which together describe the mushroom’s "naked or bald caps." The species name Junonius honors the Roman goddess Juno, the daughter of Saturn and wife of Jupiter.

Common names:

Big Laughing Gym
Laughing Jim
Spectacular Rustgill
Laughter Mushroom
German (Beringter Flämmling)
Netherlands (Prachtvlamhoed)
Czech Republic (Šupinovka nádherná)

Mushroom Identification

Cap: 1.97 to 10.24 inches (5 to 26 cm), convex to nearly flat; dry, finely silky, brownish orange; inrolled margin when young.
Gills: Narrowly attached to the stem; close, frequent short-gills; orangish yellow, becoming orange-brown; stains brown.
Stem: 3.54 to 6.3 inches (9 to 16 cm) long; 0.59 to 1.18 inches (1.5 to 3 cm) thick; equal or swollen in the middle; silky-fibrillose, balding with age; thin ring at the top with orange spores; dull yellow to brownish orange; bruises brown.
Flesh: Thick, firm, orangish yellow; does not change when sliced.
Odor and Taste: Not distinctive, with a bitter taste.
Spore Print: Rusty orange to rusty brown.
Habitat: Saprobic on rotting wood of hardwoods and conifers; clusters; summer and fall (fall through spring on the West Coast); widely distributed in North America.
Chemical Reactions: KOH red, then black on cap surface.
Microscopic Features: Spores 8–11 x 4–6.5 µm; subamygdaliform, verrucose, orangish golden in KOH; dextrinoid. Pleurocystidia inconspicuous; basidiole-like. Cheilocystidia 25–35 x 2–4 µm; cylindric-flexuous, capitate to subcapitate apices; thin-walled, smooth, orangish in KOH. Pileipellis a cutis of encrusted hyphae 2.5–10 µm wide. Clamp connections present.

Look-Alikes

Gymnopilus penetrans

Can look similar but this lacks the ring on the stem.
Phaeolepiota aurea

Has a yellowish spore print.
Omphalotus illudens

Lacks a veil and has a whitish-cream spore print.
Galerina marginata

The cap is smaller and browner.
Desarmillaria caespitosa

Has a white spore print, but has no ring.
Gymnopilus ventricosus

Very similar and doesn't contain psilocybin.

FAQ

Why is it Called Laughing Gym?

The name comes from Japanese folklore, where a mushroom called "waraitake" or "laughing mushroom" caused people to dance and laugh. This story, linked to the mushroom Gymnopilus junonius, inspired the name.

What Are the Symptoms of Gymnopilus Junonius?

Consumption of this mushroom can lead to a range of symptoms, most of which are related to its hallucinogenic effects. Here are the typical symptoms:

1️⃣ Psychoactive Effects:

Hallucinations: Visual and auditory hallucinations are common.
Euphoria: A sense of intense happiness or euphoria.
Altered Perception: Changes in the perception of time, space, and reality.
Distorted Thinking: Thoughts may become confused, bizarre, or disjointed.
Emotional Changes: Mood swings, ranging from intense joy to anxiety or paranoia.

2️⃣ Physical Effects:

Nausea and Vomiting: Some individuals may experience gastrointestinal discomfort.
Dizziness: A feeling of lightheadedness or vertigo.
Pupil Dilation: Enlarged pupils are common.
Muscle Weakness: A feeling of weakness or fatigue in the muscles.

3️⃣ Other Potential Effects:

Anxiety or Paranoia: In some cases, especially at higher doses, the experience can be frightening, leading to anxiety or paranoia.
Uncontrollable Laughter: As the name "Laughing Gym" suggests, uncontrollable laughter can occur.
Confusion: Difficulty in focusing or understanding one's surroundings.

The intensity of these symptoms can vary depending on the dosage, the individual's mental state, and the environment in which the mushroom is consumed. The effects typically begin within 20 to 60 minutes of ingestion and can last several hours. Because of the potential for severe psychological effects, Gymnopilus junonius is considered unsafe for consumption and should not be ingested recreationally.

Where Can I Find Big Laughing Gym?

This mushroom has often been confused with other species in the past. To help you find the right one, here’s some information on where similar Gymnopilus species grow and what’s known about their hallucinogenic effects:

G. junonius: Found on hardwoods (and sometimes conifers) in Europe, South America, and Australia. It’s inactive, meaning it doesn’t have hallucinogenic properties.
G. voitkii: Grows on conifers in British Columbia, eastern Canada, and the U.S., but it might be found in other areas too. Its activity is unknown.
G. ventricosus: Also found on conifers, mostly west of the Rocky Mountains, and it may overlap with the range of G. voitkii. It’s inactive.
G. luteus: Found on hardwoods in the eastern U.S. and Canada. It’s active, meaning it has hallucinogenic properties.
G. subspectabilis: Grows on hardwoods in Quebec, Ontario, and Michigan, but might be found elsewhere. A mycologist named Alan Rockefeller believes this species contains psilocybin, but there aren’t any published studies to confirm this.
G. speciosissimus: Found on hardwoods in Quebec and Ontario, with a possible broader range. It stains blue-green, but it’s not confirmed to contain psilocybin.
G. orientispectabilis: Grows on hardwoods in Japan. It’s likely active, meaning it probably has hallucinogenic properties. There might be other similar Gymnopilus species in Japanese woodlands with varying levels of psilocybin, but more research is needed.

What Are the Effects of Laughing Gym Mushrooms?

The effects vary. Some report mild, kava-like effects, while others experience stronger, psychedelic reactions. However, it can also cause severe, unpleasant symptoms. The mushroom is poisonous, so consuming it carries risks.

Synonyms

Agaricus junonius Fr.
Agaricus aureus Bull.
Agaricus junonius Fr. 1821
Agaricus spectabilis Weinm.
Dryophila junonius (Fries) Quélet (1886), Enchiridion fungorum in Europa media et praesertim in Gallia vigentium, p. 68
Fungus aureus (Gray) Kuntze
Gymnopilus junonius (Fries) P.D. Orton (1960), Transactions of the British mycological Society, 43(2), p. 176
Gymnopilus spectabilis A.H. Smith (1949), auct.
Gymnopilus spectabilis var. junonius (Fries) Kühner & Romagnesi (1953), Flore analytique des champignons supérieurs, p. 323
Lepiota aurea Gray
Pholiota aurantiaca Thesleff, 1920
Pholiota citrinofolia Métrod (1962) [1960-61], Bulletin de la Société des naturalistes d'Oyonnax, 14-15, p. 141
Pholiota gigantea Naveau, 1923
Pholiota grandis Rea, 1903
Pholiota junonia (Fries) P. Karsten (1879), Bidrag till kännedom af Finlands natur och folk, 32, p. 301
Pholiota spectabilis var. junonia (Fr.) J.E. Lange, 1940
Tricholoma aureum (Gray) Sacc.