Psilocybe allenii is a species that was recently described to science, only 2012, though well known to those who cultivated it in its range. For decades, it was identified as “P. cyanofriscosa” in the city of San Francisco and surrounding areas. Its moderate to very high potency has made it highly sought-after in the parks of the Pacific Northwest of North America.
“If you go to Golden Gate Park in December you will see hundreds of hippies looking at the wood chip landscaping for Psilocybe cyanescens and Psilocybe allenii.” Alan Rockefeller, American Mycologist
The habitat preferences of P. allenii are amenable to finding them in urban areas. Their preference for woody debris has made them a near staple of fresh wood chips in their range. Specifically hardwood chips are a favorite of this species. Regardless, P. allenii is rarely found far from the coast; it is commonly found within 16 kilometres and rarely up to 160 kilometres.
P. allenii can grow to a large size, with caps growing to 9 centimetres. The edge is often straight, sometimes curved inwards. The removable pellicle makes the cap sticky or slippery when wet, to the extent that it may be difficult to harvest moist, and slippery, mushrooms. They are often identified by their thick, white rhizomorphs (root-like structures) growing near the base.
Despite these features, P. allenii is frequently confused with other Psilocybe species. It is highly similar to P. cyanescens, sharing the same range and potency, though lacking the characteristic wavy cap. P. serbica and P. subaeruginosa are indistinguishable other than their ranges, P. azurescens only differs by a longer stipe and frequent umbo.
Few features distinguish P. allenii. It commonly has a “ring zone” from the remnants of its veil. It is rarely found outside of groups or clusters of fruiting bodies, found in cold weather between September and January. As with most other Psilocybe species, it is readily bluing with handling and damage, suggesting a relatively high concentration of psilocin and psilocybin.
P. allenii has such a potency that three grams of dried material can be considered an enormous dose. Its consumption is aided by a characteristic, but mild, floury scent and flavour common among the Psilocybe. The potency, along with its ease of cultivation, makes this mushroom a potential player in the commercial market.
Growing P. allenii is easy, it is considered a “fast and aggressive” species in artificial cultivation. It grows happily on agar, grain spawn, wood chips and even sawdust. If lucky, and living in the range, it is a common visitor in lawns and parks, along with other potent Psilocybe species. Though new to science, P. allenii and its cousins have been entertaining those on the West coast for decades.