psilocybe allenii mushroom
Original Photo by David Reishi via Mushroom Observer

Psilocybe allenii: The Bay Area Shroom No One Can Recognize

Meet Psilocybe allenii, the mushroom that evaded even skilled mycologists for decades.

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If you’ve ever hunted for mushrooms in a nearby forest or pasture, then you probably already know: It’s not easy to tell mushrooms apart. Even professional mycologists get it wrong sometimes. Mushroom identification has always encouraged animated debate. Whether you’re out on a foray, or at home on a forum, there’ll always be a second opinion (or third, or fourth) as to what exact mushroom you’re looking at. Things get even more animated when the mushroom in question might be unknown to science, but may closely resemble other named species—as is the case with Psilocybe allenii.  

First, some background: Small differences in the way a mushroom looks might indicate a possible new species, or it could just be part of the wide variability of the characteristics of a known species. With modern advances in rapid genetic sequencing, you would think such arguments could be easily settled, but this is not always the case. Deciding where the genetic code of one species ends and another begins can also be widely contested. In most cases, such debates are considered settled when a group of scientists provides sufficient evidence of these differences. The evidence is usually a combination of visual characteristics and genetic markers for a species to be considered “new.” Once this evidence is accepted by the wider scientific community, the original researchers who did the hard work get the opportunity to name their new discovery. In the world of mycology, this story plays out with Psilocybe allenii, which received its formal distinction from Psilocybe cyanescens in 2012.

Read: Psilocybe cyanescens: A Mycologist’s Guide to Wavy Caps

An Introduction to Psilocybe allenii

In the past, Psilocybe allenii has slipped by even experienced mycologists. Published photographs were often attributed to incorrect or unknown species, from as far back as the late 1970s. Mycologist and writer David Aurora is widely thought to have attributed photos of this species to Psilocybe cyanescens in his 1979 book, Mushrooms Demystified. Even Paul Stamets, in his 2005 book Mycelium Running, is also thought to have included a photo of Psilocybe allenii, describing it as a “probably new, or at least newly imported species.” In online mycology forums from the mid-2000s, Psilocybe allenii was known informally as “Psilocybe cyanofriscosa,” due to its similarity to Psilocybe cyanescens (“cyano”) and the fact this species is mostly observed around San Francisco (“friscosa”). 

psilocybe allenii mushroom
Photo by Alan Rockefeller via Mushroom Observer

Throughout all the discussions around this strange mushroom, one of the most determined advocates for the need for more thorough investigation was the controversial mycologist John Allen (aka Mushroom John). Mushroom John is a fanatical record keeper of all things mushroom; he’s written 11 books, countless articles and managed to clock up over 13,000 posts on The Shroomery, before he was banned in 2007 after clashing with moderators and the community. In the late 2000s, in his quest to find out more about this unusual mushroom, John Allen donated a number of samples he collected from the University of Washington Campus to Dr. Jan Borovička, a fungal researcher at the Czech Academy of Science in Prague. Dr. Borovička went on to team up with Alan Rockefeller and Peter Werner to study the genetics and visual characteristics of Mushroom John’s samples, publishing their findings of this new species in a paper in 2012. The species name chosen was Psilocybe allenii—a name that acknowledged John Allen, and his determination to put the debate to rest.

Psilocybe allenii Identification

Due to the long-acknowledged similarity between Psilocybe allenii and Psilocybe cyanescens, the two share a large number of visual characteristics. The caps of both species share the same caramel-brown color when wet, which changes to a yellowish-straw as they dry out. Both Psilocybe allenii and Psilocybe cyanescens also lack an umbo—the distinct pointed cap present on some mushrooms, such as Psilocybe azurescens and Psilocybe semilanceata and Psilocybe hoogshagenii. Although the caps of Psilocybe allenii can grow slightly larger (up to around 7 centimeters, or 2 ¾ inches) than Psilocybe cyanescens, their size range is fairly similar.

psilocybe allenii mushroom
Photo by Spanda via Mushroom Observer

The gills of Psilocybe allenii are also similar to Psilocybe cyanescens—both are adnate (broadly attached to the stem), though Psilocybe allenii sometimes has notched gills (also known as sinusate). The gill color of both species also runs from light grey/brown to dark brown as the mushroom matures. Even a microscope won’t help you too much as typical microscopic features, such as the spores or the cystidia (prominent cells on the edges of the gills), often don’t show a difference between Psilocybe allenii and Psilocybe cyanescens.

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The fibrous whitish stem, farinaceous (flour-like) odor, and strongly rhizomorphic (root-like) mycelium doesn’t set Psilocybe allenii apart from Psilocybe cyanescens either. Neither does its strong bluing reaction, which is typical of most mushrooms in the genus Psilocybe. At this point, you might be wondering: “Well, what does make Psilocybe allenii so different then?” 

psilocybe allenii mushroom
Photo by wwolfe28 via Mushroom Observer

Psilocybe allenii Habitat

Psilocybe allenii can be found within 50 to 100 miles of the western coastline of the USA, growing from Washington to San Francisco. They can grow in huge numbers and are frequently found in the San Francisco Bay Area. The origin of this species in natural habitats is still unknown, and to date, Psilocybe allenii has never been found outside of urban areas. This species is known as a synanthrope—an undomesticated species that lives in close proximity to human habitat (other synanthropes include raccoons and pigeons). As a result, the preferred habitat of Psilocybe allenii are the well-irrigated wood chip landscaping beds typically found around college campuses, apartment complexes, and alongside highways. Well-maintained and frequently replenished wood chip beds are even better locations; as Psilocybe allenii mycelium colonizes and breaks down wood chips at an alarming rate, so patches typically need feeding fresh wood chips each year or so to keep producing mushrooms.

Their growing season coincides with the arrival of the fall rain, usually late September, with peak growth occurring around late November to early December. By early January very few mushrooms remain and the patch goes dormant, usually until the next fall. Although Psilocybe cyanescens also begins fruiting at a similar time, they can continue to grow up until April if the weather stays wet. 

psilocybe allenii mushroom
Photo by David Reishi via Mushroom Observer

Psilocybe allenii Potency

Though no scientific potency studies have been performed to date, Psilocybe allenii is anecdotally reported to have a similar potency to Psilocybe cyanescens. Wood-loving Psilocybe species, in general, are thought to have a greater potency than the growers’ favorite, Psilocybe cubensis, though previous research suggests that the potency of wild foraged Psilocybe cyanescens can vary from 0-1.84 percent psilocybin and 0.04-1.81 percent psilocin, likely due to environmental factors. Though little data has been gathered on Psilocybe allenii to date, it is likely that a similar variability in potency may exist, not to mention the presence of other potentially psychoactive alkaloids such as baeocystin and norbaeocystin. As always with dosing for the first time, it’s recommended to start low and go slow until you understand the potency of your particular batch. As with other wood-loving Psilocybe species, there may also be a risk of wood lover’s paralysis.

Psilocybe allenii look-alikes

galerina marginata mushroom
Galerina marginata look-alike | via Wikimedia Commons

Due to their similar visual characteristics, any species that bears a resemblance to Psilocybe cyanescens should also be considered against Psilocybe allenii. These include mushrooms from the genera Galerina, Cortinarius, Hypholoma, and Leratiomyces. Such species are able to cause symptoms ranging from stomach upset, all the way through to organ damage and even death. As with all psilocybin mushrooms, the two key high-level identification features are:

  • Staining/bruising blue when damaged; AND
  • Purple-black spores

These two identification features almost guarantee that the mushroom you’re looking at contains psilocybin, but it never hurts to seek identification tips from other sources like The Shroomery, Mushroom Observer, or iNaturalist to confirm the species you’re looking for. Also check in with local mycology groups, especially if it’s obvious that they’re open to discussing psychoactive species.

As always, if you have any doubt about the species you’re about to ingest, then it’s best to leave it alone. Confident mushroom identification takes time and hard work, so don’t rush to develop your own knowledge and save yourself a trip to the emergency room. Wondering if you’ve accidentally ingested a poisonous mushroom is far from the ideal set and setting to begin a potential psychedelic experience.  

Read: Where Do Magic Mushrooms Grow?

Psilocybe allenii Cultivation

psilocybe allenii mushroom
Photo by Alan Rockefeller via Mushroom Observer

Much like Psilocybe cyanescens, Psilocybe allenii seems pretty resistant to the indoor growing setups commonly used for Psilocybe cubensis. Being a wood-loving species and preferring cooler temperatures, Psilocybe allenii is a perfect candidate for local wood chip beds or outdoor monotubs. Although, it’s important to keep in mind that cultivating psilocybin mushrooms is still illegal in many areas. Though cultures can be started on grain, they need wood or lignin-rich material to produce mushrooms. Luckily they’re not too fussy and will grow on most hardwoods like alder, oak, beech, or birch, to name a few. Jars of whole chips or sawdust can be inoculated then spawned to outdoor beds in shady areas, where seasonal conditions will affect flushes from year to year. Keep topping up your beds with fresh chips once a year and mushroom production will continue for many years to come. 

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