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A Quick Guide To Blue Magic Gym (Gymnopilus aeruginosus)

It may be yellow. It may be blue—no matter. This mushroom will have a magical effect on you.

DoubleBlind Mag

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Blue Magic Gym (Gymnopilus aeruginosus, previously Pholiota aeruginosa) is one of the lesser-known magic mushrooms. The genus Gymnopilus—an Ancient Greek portmanteau of “gymnós” (naked) and “pîlos” (cap)—contains around 200 species. Still, only around 14 are known to contain psilocybin—aeruginosus included.

Rolf Singer first described this mushroom in scientific literature in 1951. Singer reportedly gave the mushroom the epithet “aeruginosus” due to the blueing reaction typical of psilocybin-containing species. This same feature inspired its common English name: Blue Magic Gym. In Japan—where this mushroom also grows—G. aeruginosus has the common name “midori-sugitake,” meaning “green cedar mushroom,” after its favored coniferous forest habitat. 

Gymnopilus aeruginosus Mushroom Effects 

Photo Depicting Mushroom in the Wild
Gymnopilus Aeruginosus. Image Courtesy of Drew Henderson via Mushroom Observer.

For those of you who manage to find G. aeruginosus (and are confident you haven’t accidentally picked one of its poisonous look-alikes), your experience of its effects may be similar to those of other psilocybin-containing mushrooms. Some people who try certain active Gymnopilus mushrooms claim the experience feels different compared to more common magic mushrooms like Psilocybe cubensis. However, it’s hard to know what combination of factors contributes most to the subjective effects of the mushroom: It could be set and setting, or it could be a combination of other active compounds found in any psychedelic mushroom, not just G. aeruginosus

Is Gymnopilus aeruginosus psychedelic?

One of the few studies of G. aeruginosus, conducted in 1978, found psilocybin present in North American samples of this mushroom. However, the researchers could not measure the precise concentration due to the analysis method used. 

Conversely, a study of hallucinogenic mushrooms conducted in Japan in 1981, which included a Japanese sample of G. aeruginosus, found no detectable levels of psilocybin. However, given the confusion around Gymnopilus species in general, it could be a case of mistaken identification. A recent 2020 genetic study described a new psychedelic species of Gymnopilus orientispectabilis. It used photographic archive evidence to suggest at least two other Japanese species in this genus that may be awaiting discovery. (Scientists estimate that we’re only presently aware of a small percentage of fungi that exist.) 

Photo Depicting Mushrooms Growing in Forest
Gymnopilus Orientispectabilis. Image Courtesy of Mushroom Observer.

Singer himself reported G. aeruginosus to contain “an alkaloid which is said to have psychotropic effects, and the surface of the carpophores turn blue or green as in the hallucinogenic species” in his 1975 book “Agaricales in Modern Taxonomy.” However, since his book predates most published studies of this mushroom, it’s unclear if he was speaking from personal experience of this mushroom or merely reporting what others had told him.

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Gymnopilus aeruginosus Potency

With most research on naturally occurring psilocybin historically focussed on mushrooms in the genus Psilocybe (and, to a lesser extent, Panaeolus), it may not be surprising that no studies have quantified psilocybin or other commonly occurring alkaloids in G. aeruginosus. Studies of other Gymnopilus species have found 0.0031-0.0131% psilocybin for G. dilepis0.12% for G. validipes0.012-0.029% for G. liquiritiae, with the highest potency recorded for G. purpuratus at 0.34%. Based on anecdotal reports, G. aeruginosus may fall within the potency range of previous studies. At best, this mushroom may be around half the potency of a typical Psilocybe cubensis mushroom.

Photo Depicting Two Mushrooms Growing on Rotting Tree
Psilocybe Cubensis. Image Courtesy of Scott Ostuni via Mushroom Observer.

How To Identify Gymnopilus aeruginosus

Even experienced mycologists sometimes struggle to separate the different Gymnopilus species, as they share many common features. Some use microscopes or DNA samples to help with identification, but these aren’t always accessible to beginners.

Key Characteristics 

G. aeruginosus is generally light tan to orange-brown but can display a wide range of colors. Younger mushroom caps can show patches of greyish-blue-green. However, some descriptions reference other colors associated with this mushroom, from salmony pink to wine red.

The cap of G. aeruginosus can grow to around 6 inches (15 cm) wide but is typically much smaller than this. The surface of the cap is covered in flat hairy scales, which stand out by their orange or reddish-brown color.

The edges of the typically convex cap can have flakey remnants of the partial veil—a membrane that covers the gills when the mushroom is developing. The cap edges curve inwards in younger mushrooms but opens up as the cap becomes almost flat with age.   

The gills of G. aeruginosus are narrowly attached to the stem and crowded under the cap. In younger mushrooms, the gills start yellowish-orange and become orange, darkening to orange-brown in older specimens.

G. aeruginosus can grow up to nearly five inches (12 cm) tall but more typically are found at around two inches (five cm). The stem (stipe), which holds up the cap, is around ½ inch (1.25 cm) thick and is generally equal in width (or sometimes gradually tapering towards the cap). The stipe is a similar color to the cap and may be covered in similar hairy scales, though these might not always be present. The stem appears fibrous and may sometimes have a partial veil dusted with spores.

Like some other mushrooms of the Gymnopilus genus, G. aeruginosus has a bitter taste.


Like all Gymnopilus species, the spores of G. aeruginosus are a rusty-orange color. 

Where to find Blue Magic Gym

Photo Depicting Two Mushrooms Growing on Tree Bark
Gymnopilus Aeruginosus found in Washington State, USA. Image Courtesy of Caleb Brown via Mushroom Observer.

G. aeruginosus is found on both the east and west coast of the US, as well as in Japan, Taiwan, and Mainland China. They grow as patches of single mushrooms (gregarious) or in small clumps (cespitose) on hardwoods and conifers. You can find these mushrooms on logs or stumps, as well as from more manicured beds laid with wood chip mulch. In the US, G. aeruginosus has a long growing season, typically between May and November

Gymnopilus aeruginosus Look-alikes

As well as being hard to distinguish from other Gymnopilus species, many other mushroom species can be mistaken for G. aeruginosus. Some of these look-alikes can be deadly, so always take care to correctly identify what you find, possibly with the help of someone more experienced. If you’re ever in doubt as to the identity of a mushroom you find, don’t eat it!

One particularly nasty look-alike is the aptly named deadly webcap (Cortinarius rubellus), which can cause severe kidney failure and death. At least one magic mushroom forager fell foul of its effects in 1996. The deadly webcap grows mostly in woodlands. The cap has a typical bump (umbo) in the center, giving it a more pointy appearance. However, such an identification feature may not be reliable, as the caps of older deadly webcaps can flatten out in an appearance similar to G. aeruginosus.  

Another deadly look-alike is the funeral bell (Galerina marginata), which can cause a range of symptoms, from kidney and liver failure to internal bleeding, vomiting, diarrhea, and ultimately, death. Though typically smaller than G. aeruginosus, it can still be mistaken for younger specimens. The cap of the funeral bell is smooth and changes color with humidity (hygrophanous), from an orange-brown when wet to a duller tan color when dry. 

Less lethal but growing in similar habitats are the various jack-o-lantern mushrooms (e.g., Omphalotus olarius), named for their bioluminescent properties. These mushrooms more closely resemble chanterelles, with their gills running down the stems, but they could still be mistaken by those less experienced. If you make such a mistake, expect stomach cramps, vomiting, and diarrhea.

Cultivating Gymnopilus aeruginosus 

Few people have cultivated G. aeruginosus, with some claiming the effort required to develop it isn’t worth the effort compared to more potent woodlovers like Psilocybe ovoideocystidiataPsilocybe cyanescens, and Psilocybe allenii.

Still, G. aeruginosus will happily grow on agar and grain. Due to its natural preference for all types of wood, this species could be grown on hard and softwood mulch patches. They often grow on logs or stumps in their natural habitat, meaning this species would be a good candidate for the sorts of log cultivation methods you might use for shiitake or lion’s mane.

As a less commonly cultivated mushroom, finding spores or mycelium in your typical culture supply shops may be difficult. So, you may have to collect spores from wild samples yourself and make a syringe or clone your finds on agar—if it is legal or decriminalized to do so in your region. Though growing G. aeruginosus might take a bit of extra work, by working with locally foraged species, you’ll have a growing project that’s well adapted to growing in the climate found in your backyard.

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