Paul Stamets and Jochen Gartz
A new caerulescent Psilocybe from the Pacific Coast of
A new taxon from the Pacific Northwest of North American is described. This
species can be placed into Stirps Cyanescens of the Sections Caerulescents
Singer (Singer, 1948; Singer & Smith, 1958a) or into the more recently
constructed Section Cyanescens as amended by Guzman (1983). This new species
is autumnal and lignicolous, living in soils enriched with deciduous wood-
debris, characterestic of riparian woodlands of the coastal regions of the
Pacific Northwest of North America. Strongly bruising bluish to indigo-black,
this Psilocybe species features a hazelnut to caramel-colored pileus and a
stipe whose base radiates clusters of white rhizomorphs. This novel species
is delineated through a combination of morphological and microscopic
feautures and possesses unusally high concentrations of psilocybin, psilocin
Psilocybe azurescens Stamets & Gartz sp. nova
Pileo ochreato-brunneo, hygrophano, viscido, pellicula separabili intructo,
conico dein convexo, plano 30-100mm lato, umbonato. Lamellis sinuato-adnatis,
pallidis vel brunneo. Stipite albo, stricto, elongato, 90-200mm, fibrillis
cum strigositate basis caerulescentibus. Carne caerulescente. Sporis 12-13,5
x 6,5-8.0 um. Cystidiis fusoid-ventricosis. Cheilocystidiis 23-28 x 6.5-8.0
um; pleurocystidiis 23-35 x 9-10 um.
Pileus 30-100mm in diameter, conic to convex, expanding to broadly convex and
eventually flattening with age with a pronounced, persistent broad umbo;
surface smooth, viscous when moist, covered by a separable gelatinous
pellicle; chestnut to ochraceous brown to caramel in color often becoming
pitted with dark blue or bluish black zones, hygrophanous, fading to light
straw color in drying, strongly bruising blue when damaged; margin even,
sometimes irregular and eroded at maturity, slightly incurved at first, soon
decurved, flattening with maturity, translucent striate and often leaving a
fibrillose annular zone in the upper regions of the stem. Lamellae ascending,
sinuate to adnate, brown, often stained info-black where injured, close,
with two tiers of lamellulae, mottled, edges withish. Spore-print dark
purplish brown to purplish black in mass. Stipe 90-200mm long by 3-6mm thick,
silky white, dingy brown from the base or in age, hollow at maturity.
Composed of twisted, cartilaginous tissue. Base of stem thickening downwards,
often curved, and characterized by coarse white aerial tufts of mycelium,
often with azure tones. Mycelium surrounding stipe base densely rhizomorphic,
silky white, tenaciously holding the wood-chips together, strongly bruising
bluish upon disturbance. Odor none to slightly farinaceous. Taste extremely
Clamp connections abundant. Ixocutis gelatinous, hyaline hyphae, 1.5 - 5.5um
in diameter. Sub-pellis a brownish band, more highly pigmented than pileal
trama. Lamellar trama regular, composed of hyphae 5 - 15 um in diameter,
slightly encrusted with brown pigments; subhumenium a subcellular compact
layer, 10um thick. Pileal trama 5 - 15um thick. Pleurocystidia abundant,
fusoid-ventricose, tapering to a narrow but short neck, bluntly papillate,
23-35 x 9-10 um. Cheilocystidia forming a nongelatinized sterile band, nearly
identical to pleurocystidia measuring 23-28 x 6.5-8.0 um. Basidia 4-spored,
measuring 27-30.5 x 6.3-7.2 um. Spores 12-13.5 x 6.5-8.0 um, rich reddish
brown in KOH and light purplish vinaceous in aqeous ammoniacal solutions.
Wall thickness less than 1 um. Caulocystidia abundant above the annular zone
and similar to pleurocystidia but thicker walled and more irregular,
measuring 43um long with undulated necks. Cortial hyphae on stipe slightly
thickened, almost subgelatinized walls, 3 - 5 um in diameter with clamps and
brown intra-perital pigment. Caulocystidia absent below annular zone. Tissue
notably awash with bluish tones.
Habit & Habitat:
Cespitose to gregarious on deciduous wood-chips and/or in sandy soils rich in
lignicolous debris. Aspect collyboid, generating an extensive, dense and
tenacious mycelial mat, Psilocybe azurescens causes the whitening of wood. Fruitings
begin in late September and continue until harsh frost, usually mid-November.
Specimens were first collected on an alluvial plain along the Columbia river
network near Astoria, Oregon in 1979. Fruitings of this species are known
from Oregon and Washington. Holotype: A dried collection of fruitbodies
cultivated on alder (Alnus rubra) wood-chips using the methods described by
Stamets (1993) outdoors, harvested on 11/21/93 and deposited at WTU. Original
clone used for propagation was from Astoria, Oregon on 10/30/79. Additional
collections from Tillamook and Astoria, Oregon in October 1990 were collected
by one of the authors (Jochen Gartz) and deposited in LZ.
Psilocybe azurescens generally resembles Psilocybe bohemica Sebek, Psilocybe
cyanofibrillosa Guzman & Stamets, Psilocybe cyanescens Wakefield, Psilocybe
eucalypta Guzman & Walting, Psilocybe mairei Singer, Psilocybe serbica Moser
& Horak and Psilocybe collybioides Singer & Smith. Complete reproductive
barriers have been found be one of the authors (Jochen Gartz) between
Psilocybe azurescens and Psilocybe bohemica as well as between Psilocybe azurescens and
Pacific Northwest European collections of Psilocybe cyanescens.
In it's natural habitat, the general aspect of Psilocybe azurescens is most
similar to Psilocybe cyanofibrillosa Stamets & Guzman but differs in several
significant macroscopic features. Psilocybe azurescens has pleurocystidia
whereas Psilocybe cyanofibrillosa has long necked, lageniform cheilocystidia,
often forked, while Psilocybe azurescens has singly formed, fusoid ventricose
cheilocystidia with short necks. Macroscopically Psilocybe azurescens is much larger
in form and quickly bruises bluish to indigo-black upon handling. The
bruising reaction in P. cyanofibrillosa is less intense and comparatively
slow in appearing, which directly reflects it's low psilocybin content
(Bocks, 1968; Stamets et al. 1980). Both species are characterized by non-
undulating pileal margins.
Psilocybe azurescens also closely resembles a variety of Pacific Northwest
Psilocybe widely reported as Psilocybe cyanescens Wakefield, a species
originally discovered in the British Isles. This variety of Psilocybe
cyanescens gained considerable notoriety in the mid-1970's (Weil, 1975, 1977;
Pollock, 1975; Ott, 1975; Guzman & Ott, 1976; Guzman et al., 1976). Yet,
mushroom has probably been confused with other taxa. The mushroom portrayed
in many popular field guides and identified as Psilocybe cyanescens (Arora, 1979 &
1991; Lincoff & Mitchel, 1977; Lincoff, 1981; Menser, 1977; Ott & Bigwood,
1978; Stamets, 1978) differs from the type in the relative number of surface
In the Pacific Northwest, Psilocybe azurescens can be macroscopically distinguished
from Psilocybe cyanescens by the following combination of features. Psilocybe azurescens
has a cap margin characteristically even, not undulating and has a persitent,
pronounced umbo at the disc when the pileus fully expands. The variety of P.
cyanescens from the Pacific Northwest is characterized by distinctive,
exaggerated undulating margin, resembling a sine-wave at maturity and is
notably non-umbonate. In general, Psilocybe azurescens, as it is presently
understood, is substantially larger than most collections of Psilocybe cyanescens.
Microscopically, the pleurocystidia in Psilocybe azurescens are mucronate whereas
the Pacific Northwest form Psilocybe cyanescens can become distinctly capitate at
maturity. Otherwise, the microscopic features of Psilocybe azurescens are largely
coincident within the range reported for the Pacific Northwest Psilocybe cyanescens.
Krieglsteiner (1984, 1986) extensively studies collections of Psilocybe from
Europe, some of which were determined to be Psilocybe cyanescens. He proposed
that Psilocybe mairei Singer, Psilocybe serbica Moser & Horak and Psilocybe
bohemica could be conspecific with Psilocybe cyanescens Wakefield because
these taxa could not be delineated microscopically. However, one significant
feature which characterizes Psilocybe bohemica and separates this species
from these aforementioned taxa and from Psilocybe azurescens is that the
pilei of Psilocybe bohemica become white upon drying. Furthermore, one author
(Jochen Gartz) has found complete reproductive barriers between 80 random
pairings of monokaryons from Psilocybe azurescens, Psilocybe cyanescens and
Psilocybe bohemica. Since monokaryons from single spore isolates from each of
these species have proved to be incompatible, these taxa appear to be auto-
nomous. Former research (Gartz, 1993) has also shown that complete repro-
ductive barriers exist between Pacific Northwest strains of Psilocybe
cyanescens and Czechoslovakian collections of Psilocybe bohemica. Mating
studies paired single spore isolations and clamp connections failed to
form, an indication of incompatibility. Furthermore, monokaryons from a
collection of Psilocybe cyanescens (non-pleurocystidiate form) from Austria
in October of 1992 also failed to form dikaryotic mycelia when paired with
strains of Pacific Northwest Psilocybe cyanescens (pleurocystidiate form),
Psilocybe azurescens and Psilocybe bohemica, respectively.
A closely related species is Psilocybe eucalypta Guzman & Watling. Psilocybe
eucalypta has smaller and narrower cheilocystidia, only 15-25 x 4.4-6.6 um in
comparison to Psilocybe azurescens cheilocystidia which measure 23-28 x 6.5-8.0 um.
Furthermore, Psilocybe azurescens produces a more massive fruitbody, with a pileal
diameter of 30 to 100 mm whereas P. eucalypta is smaller, falling within a
range of 15-38 mm. P. eucalypta has thus far only been reported from the
region centering around eastern Australia. Lastly, Psilocybe serbica Moser &
Horak (1968), a temperate species, can be easily separated from Psilocybe azurescens
by it's lack of pleurocystidia and it's non-umbonate form. Another related
species, Psilocybe collybioides Singer & Smith, known at present from
Argentina, shares many features common to Psilocybe azurescens save for it's
exceptionally small spores, measuring only 5.5-10 x 3.5-6.5 um. These com-
binations of features separate Psilocybe azurescens from the aforementioned taxa.
Psilocybe azurescens is being named for the soft blue tones present on the
mushroom, before handling or damage, especially along the cap margin and in
the basal mycelium. Additionally the name also honors the son of one of the
authors (Paul Stamets).
In comparison to other species of Psilocybe, the fruitbodies of Psilocybe
azurescens contain unusually high concentrations of psilocybin, psilocin and
baeocystin - accumulating to more than 2% of the dry biomass of the mushrooms
(Beug & Bigwood, 1982; Gartz, 1989, 1992-1994; Wurst et al., 1984). Thin
Layer Chromatography (TLC) reveals a nearly identical profile of extracts
from P. semilanceata and Psilocybe azurescens (psilocybin, baeocystin and six minor
alkaloids), differing only in psilocin content (Gartz, 1985). Baeocystin is
present in high concentrations in Psilocybe azurescens and P. semilanceata. Gartz
(1993) has determined that baeocystin is also a hallucinogenic compound.
Research by Gartz (1989) showed alkaloid synthesis in Psilocybe cubensis
(Earle) Singer is suppressed when the mycelium is grown using agar media
supplemented with more than 10% mal sugar. Psilocybe azurescens reacts similarly.
Research has also shown that alkaloid content is generally low in the mycelia
compared to the fruitbodies. With Psilocybe cubensis, the main alkaloid
synthesis occurs during the differentiation of the mycelia to the fruitbodies
(Gartz & Muller, 1989). Further, younger fruitbodies frequently have higher
alkaloid levels than more mature ones (Gartz, 1992/1993). As Table III shows,
specimens grown outdoors in Germany did not vary significantly from those
grown in the United States, after dehydratation, even when the supporting
substrates were dissimilar.
Indole alkaloid content of collection (LZ) of wild fruitbodies of Psilocybe
azurescens from Tillamook, Oregon, USA, October, 1989.
Sample 1: 50mg dry weight, 1.71% Psilocybin, 0.34% Psilocin, 0.41% Baeocyst.
Sample 2: 101mg dry weight, 1.68% Psilocybin, 0.28% Psilocin, 0.38% Baeocyst.
Sample 3: 167mg dry weight, 1.56% Psilocybin, 0.30% Psilocin, 0.32% Baeocyst.
Sample 4: 213mg dry weight, 1.51% Psilocybin, 0.31% Psilocin, 0.28% Baeocyst.
Sample 5: 270mg dry weight, 1.40% Psilocybin, 0.28% Psilocin, 0.19% Baeocyst.
Sample 6: 317mg dry weight, 1.29% Psilocybin, 0.26% Psilocin, 0.27% Baeocyst.
Sample 7: 450mg dry weight, 1.20% Psilocybin, 0.25% Psilocin, 0.31% Baeocyst.
Indole alkaloid content from naturalized, outdoor cultivated specimens of
Psilocybe azurescens, from Astoria, Oregon, USA, October, 1990.
Sample 1: 062mg dry weight, 1.78% Psilocybin, 0.38% Psilocin, 0.35% Baeocyst.
Sample 2: 123mg dry weight, 1.75% Psilocybin, 0.39% Psilocin, 0.36% Baeocyst.
Sample 3: 170mg dry weight, 1.58% Psilocybin, 0.34% Psilocin, 0.37% Baeocyst.
Sample 4: 224mg dry weight, 1.43% Psilocybin, 0.28% Psilocin, 0.31% Baeocyst.
Sample 5: 331mg dry weight, 1.18% Psilocybin, 0.19% Psilocin, 0.25% Baeocyst.
Sample 6: 472mg dry weight, 1.20% Psilocybin, 0.20% Psilocin, 0.21% Baeocyst.
Indole alkaloid content from dried, outdoor-cultivated, naturalized specimens
of Psilocybe azurescens, from Germany (A) and USA (B).
Sample 1: A - 156mg dry weight, 1.62% Psilocybin, 0.42% Psilocin, 0.38% Baeocystin
B - 165mg dry weight, 1.72% Psilocybin, 0.38% Psilocin, 0.39% Baeocystin
Sample 2: A - 213mg dry weight, 1.56% Psilocybin, 0,32% Psilocin, 0.28% Baeocystin
B - 233mg dry weight, 1.62% Psilocybin, 0.25% Psilocin, 0.24% Baeocystin
Sample 3: A - 312mg dry weight, 1.43% Psilocybin, 0.26% Psilocin, 0.31% Baeocystin
B - 341mg dry weight, 1.32% Psilocybin, 0.25% Psilocin, 0.35% Baeocystin
Sample 4: A - 412mg dry weight, 1.17% Psilocybin, 0.31% Psilocin, 0.28% Baeocystin
B - 403mg dry weight, 1.21% Psilocybin, 0.38% Psilocin, 0.19% Baeocystin
Sample 5: A - 450mg dry weight, 1.19% Psilocybin, 0.36% Psilocin, 0.24% Baeocystin
B - 465mg dry weight, 1.24% Psilocybin, 0.24% Psilocin, 0.30% Baeocystin
Variation of the amounts of alkaloids in the mycelium of Psilocybe azurescens
depending on the concentration of malt extract in solidified agar (1,5%)
after 3 weeks of colonization.
1% Malt Extract: 0.31% Psilocybin dry weight, 0.12% Psilocin, 0.12% Baeocyst.
2% Malt Extract: 0.25% Psilocybin dry weight, 0.09% Psilocin, 0.08% Baeocyst.
3% Malt Extract: 0.28% Psilocybin dry weight, 0.08% Psilocin, 0.05% Baeocyst.
4% Malt Extract: 0.27% Psilocybin dry weight, 0.04% Psilocin, 0.03% Baeocyst.
5% Malt Extract: 0.25% Psilocybin dry weight, 0.02% Psilocybin, 0% Baeocystin
6% Malt Extract: 0.18% Psilocybin dry weight, 0% Psilocin, 0% Baeocystin
8% Malt Extract: 0.05% Psilocybin dry weight, 0% Psilocin, 0% Baeocystin
10% Malt Extract: At and above 10% malt extract, the mycelium is non-blueing.
The authors would like to thank Scott Redhead and Roy Watling for reviewing
the manuscript. The senior author is grateful to Michael Beug and The
Evergreen State College for their continued support and to Azureus Stamets
for his assistance in the field. The authors also express gratitude to G. K.
Mueller from the University of Leipzig Herbarium (LZ) and Marta Semerdzieva
of Prague. Paxton Hoag and Mark Herke are credited for first collecting this
mushroom. John Allen and Eric Iseman helped in field collections.
(1) A mushroom reportedly responsible for the death of a child in Kelso,
Washington in 1962 was identified by Alexander Smith as Psilocybe baeocystis
Singer & Smith (see McCawley et al., 1962; Singer & Smith, 1958a) From
Kelso site, cultures were isolated and mushrooms were grown from mycelial
spawn. The cultured specimens have an aspect atypical of Psilocybe baeocystis
Singer & Smith and strikingly typical of the Pacific Northwest form of
Psilocybe cyanescens. These two species can be easily delineated from one
another macroscopically. Furthermore, these authors know of no successes in
cultivating P. baeocystis, despite many attempts. In contrast, Psilocybe cyanescens
can easily be cultivated on wood-chip substrates. When one of the authors
(Paul Stamets) noted these discrepancies to Alexander Smith (1982), he
responded that the identification was tentative, made from poorly preserved
spore material retrieved from stomach washings and was not without
(2) Psilocybe cyanescens Wakefield was originally described from a collection
at the Kew Gardens, Surrey, England. (See Dennis & Wakefield, 1946; Singer
Smith, 1958a; Guzman, 1983). The variety of Psilocybe cyanescens from the Pacific
Northwest has abundant and conspicuous pleurocystidia, often with distinctive
swollen apices, evenly dispersed over the surface plane of the lamellae. The
type collection of Psilocybe cyanescens by Wakefield has so few surface cystidia
that they could easily be overlooked (Wakefield, 1946; Singer & Smith, 1958b;
Krieglsteiner, 1984). The discrepancies seen between these varieties may be
significant at the species level. Further study of these taxa is warranted.
(3) Chang & Mills (1992) propose that P. eucalypta is actually P.
subaeruginosa. Guzman et al. (1993) strongly disagree with this synonymy.
Krieglsteiner (1984, 1986) believes that P. eucalypta is conspecific with