A formal description of the species was published by Elsie Wakefield in 1946 in the Transactions of the British Mycological Society, based on a specimen she had recently collected at Kew Gardens.
[5][6] Since all the psychoactive compounds in P. cyanescens are water-soluble, the fruiting bodies can be rendered non-psychoactive through parboiling, allowing their culinary use.
[5] Psilocybe cyanescens can sometimes fruit in colossal quantities; more than 100,000 individual mushrooms were found growing in a single patch at a racetrack in England.
[7] Psilocybe cyanescens has a hygrophanous pileus (cap) that is caramel to chestnut-brown when moist, fading to pale buff or slightly yellowish when dried.
There is no distinct annulus, but immature P. cyanescens specimens do have a cobwebby veil which may leave an annular zone in maturity.
[11] Fresh sporocarps and mycelia of P. cyanescens generally bruise blueish or blue-green where damaged, and the staining remains visible after drying.
This staining is most noticeable on the stem (which is white when undisturbed) but can also occur on other parts of the mushroom, including the gills, cap,[1] and mycelium.
It is often difficult or impossible to distinguish between members of the P. cyanescens complex except by range without resorting to microscopic or molecular characters.
[citation needed] The two mushrooms have generally similar habits and appearances, and bear a superficial resemblance to each other such that inexperienced mushroom-seekers may confuse the two.
[15] In the United States, P. cyanescens occurs mainly in the Pacific Northwest, stretching south to the San Francisco Bay Area.
[17] The range in which P. cyanescens occurs is rapidly expanding, especially in areas where it is not native as the use of mulch to control weeds has been popularized.
[citation needed] North American fruiting bodies of P. cyanescens have been shown to have between 0.66% and 1.96% total indole content by dry weight.
[1][5] Its potency means that it is widely sought after by users of recreational drugs in those areas where it grows naturally.
[5] Psilocybe cyanescens mycelium is easier to grow than actual fruits are, can be grown indoors,[5] and is robust enough that it can be transplanted in order to start new patches.
[22] Countries that have banned or severely regulated the possession of P. cyanescens include the United States, Germany, New Zealand, and many others.