ORIGINAL DESCRIPTION: Fragmenta Botanica, 6:19-22 (1968).

FAMILY: Cortinariaceae

DISTRIBUTION: The mushroom species was first found by J. Ferencz in Osca, Hungary, on June 15, 1965. That same year, as well as on several occasions later on, Hungarian mycologists found large numbers of mushrooms growing in different locations mainly in plantations of Populus around Budapest (Babos, 1968; Bohus et al., 1977; Gartz et al., 1986; Gartz, 1995).

In 1975, the Inocybe species was collected in Eastern Berlin for the first time. But a careful analysis of material from herbarium has shown that the mushrooms were already found in this area some years ago. So it is unclear if the species comes originally from Hungary or from other parts of Europe. During the 1980s Inocybe aeruginascens could be found in abundance at countless new locations around Berlin and Budapest. Finally, a few fruiting bodies each were also collected in Holland (1980), the Rhone Valley (Switzerland, 1984) and perhaps at the coast of the Ostsee (Germany). Its occurrence is to be expected also in other countries.

ECOLOGY: Growing on moist sand near the roots of different deciduous trees (Populus, Tilia, Quercus, Betula), mainly in May/June but till October in some years, in parks and gardens.

BOTANICAL DESCRIPTION: The members of the genus Inocybe are mycorrhizal species.Only a few mycologists are specialized in the study of this difficult genus (about 160 species in Europe).

Pileus 2-3-(4,5)cm in diam., at first obtusely conical, then in the middle umbonate, margin sometimes inflexed, ochreous yellow, ferrugineous ochre, yellowish-brown, or ferrugineous brown, usually vivid in colour, umbo a little darker and sometimes olive greenish, dry, silky, in the middle usually smooth, towards the margin finely radially fibrillose or rimoso-fibrillose. The olive greenish tinge of the pileus disappears during exsiccation, ramaining only rarely visible. Gills up to 3mm deep, at first pallid, then argillaceous brown, olive brown or tobacco brown.

Stipe 2,5-7 cm high, 2-6 mm wide, whitish-cream coloured, later light ochre or dirty ochre, when young and untouched only occasionally with a pale greenish tinge, but later or when touched becoming partially bluish green, equal or downwards a little attenuated, bulbous or not.

Flesh thin, whitish, with a greenish to bluish-green tinge in the stipe, but this colour mostly disappearing during the exsiccation.

Smell indistinctive. Spore print brown.

Cuticle formed of brownish-yello hyphae, 3-10-(12) µ m wide, with clamp connections. Gill trama rather regular. Cheilocystidia 18-31 x 8-14 µ m, thin walled, vesciculose to clavate. Basidia 20-23 x 6-8 µ m, clavate, 4-spored. Spores 7-10 x 4-5 µ m, ellipsoid to almondshaped, light brownish-yellow.

BOTANICAL OBSERVATIONS: I.aeruginascens differs in a number of morphological features from other blueing species like I.haemacta Berk. & Br. and I.corydalina Quél. I.haemacta has also a viridescent stipe but the pileus of I.corydalina is merely glaucous-olivaceous. However, the difference is not merely morphological but also ecological: the two latter species fructify in hornbeam-oak forests whereas I.aeruginascens was found only in associations with trees on sand in parks and gardens.

ETHNOMYCOLOGICAL DATA: In 1983, the species immediately attracted the attention of biochemists and clinicians, after Drewitz (1983) described psychotropic intoxications caused by these mushrooms in the city and district of Potsdam, Germany, that occurred in June and July 1980. The observed range of effects was sensational for the Inocybe genus, because many of its species (around 40) induce typical muscarine poisoning symptoms.

Muscarine causes parasympathomimetic symptoms, such miosis and increased salivation. The first reports about deaths following ingestion of the potent muscarine-containing Inocybe patouillardi Bres. date back to the early 20th century. In general, I.aeruginascens is the only European species which caused some accidental and pure hallucinogenic experience with benign somatic effects after misidentification of edible mushrooms.

Because of the German article (Drewitz, 1983), Babos (1983) reported an additional case of unintentional ingestion of I.aeruginascens in Budapest, which had happened as early as July 1, 1970. In this case, the same symptoms included subjective feelings of decreasing gravity, coloured hallucinations and spatial illusions occurred.

A German mycologist took 2,4 gr of dried mushrooms in the course of a test experiment and experienced feelings of euphoria, abstract hallucinations and a very vivid sensation of the soul in flight. The visions seemed to impart an inkling of eternity (Gartz, 1995).

In contrast to other accidental and even intentional ingestion of hallucinogenic mushrooms it was remarkable that all cases of involuntary intoxication with the Inocybe species induced a feeling of euphoria, despite a psychological state of mind likely to create extremely unfavorable internal conditions (set) for having a "positive experience" (i.e. knowledge of being poisoned by mushrooms with unknown and potentially fatal consequences). In addition, these cases happened in the course of pursuing normal, everyday activities, including appointments and other interferences (setting) which should have precipitated a much more negative type of experience.

It is very likely that additional intoxications occurred which didn't reach a scientific observer because of the benign somatic symptoms and the ending of the experience after about five hours without any lasting consequences.

BIOCHEMICAL DATA: Based on the intoxication and the blueing of the mushrooms Drewitz (1983) proposed that the mushrooms contain psilocybin or similar substances. This hypothesis was later confirmed in our investigations (Gartz, 1985, 1986, 1987; Semerdzieva et al., 1986). Shortly after the first report about the occurrence of psilocybin in each fruiting body (Gartz, 1985), other investigations were able to confirm this detection independently (Besl et al., 1985; Haeselbarth et al., 1985; Stijve et al., 1985). Baeocystin and in some fruiting bodies also tryptophan and only traces of the unstable psilocin were also present in the mushrooms (Gartz, 1986, 1987; Semerdzieva et al., 1986; Stijve et al., 1985). There was a variation of the content of alkaloids and the levels of psilocybin are comparable to the alkaloidal levels of the "classic" psychotropic mushroom Psilocybe mexicana Heim (Gartz, 1987, 1995). Baeocystin is also a psychotropic substance (Gartz, 1995).

It shoul be noted that results from the analysis of the mushrooms indicated the presence of a previously unknown alkaloid, which was named aeruginascin (Gartz, 1987, 1989). The structure of aeruginascin must be very similar to those of baeocystin and psilocybin and the levels of concentration of aeruginascin found in the mushrooms are comparable to those of psilocybin and baeocystin (Gartz, 1989). The compound is characteristic of I.aeruginascens so that tye analytical results of mushroom extracts (using thin-layer chromatography) constitute a kind of fingerprint identification of I.aeruginascens. It is very likely that aeruginascin is the compound which is able to create these "positive" experiences even after accidental ingestions of the mushrooms. Future research must focus first on the discovery of the molecular structure and later the synthesis. Subsequent studies should investigate the potentially mood-modifying influence of aeruginascin. There wasn't muscarine in any mushroom of I.aeruginascens (Gartz, 1986).

BIOCHEMICAL OBSERVATIONS: Among the other blueing Inocybe species, the analysis of I.corydalina revealed a psilocybin content of only 0,011-0,1%, but a few fruiting bodies of I.haemacta contained similar alkaloidal concentrations like I.aeruginascens (Stijve et al., 1985).