Macroscopic feat.:

• Cap/Pileus: 2-8 cm broad, convex to campanulate, soon expanding to broadly convex, often with a low, broad umbo. Dark bluish green, sometimes fading with maturity. Surface viscid when wet and covered with a bluish green, separable gelatinous pellicle. Margin even, adorned with whitish flecks, remnants from the partial veil. Flesh thin, whitish, thicker towards center.
• Gills/Lamellae: Adnately attached, broad, fawn to clay brown in color, sometimes tinged purplish, with white edges.
• Stem/Stipe: 30-80 mm long by 3-12 mm thick, nearly concolorous with cap, equal, flared towards the apex, and swelled at the base. Surface covered with whitish patches. Partial veil membranous, leaving a fragile, membranous annulus on the superior regions of the stem, which is whitish above and bluish green below, sometimes disappearing in age.

Microscopic feat.:

• Basidio/Spores: Dark vinaceous purple brown to purple black in deposit, 7.5-9 by 4.5-5 µm, ellipsoid, thick-walled with a central germ pore.
• Cheilocystidia: lageniform-capitate and bluntly capitate, 40-55 by 10-12.5 µm.
• Pleurocistidia: Mucronate, clavate, 40-60 by 10-15 µm.

Habitat: Widespread throughout the British Isles, northern Europe, and in western North America, on wood debris, in gardens, parks, and occasionally along grassy areas at the edge of woodlands. In the Pacific Northwest this mushroom grows beneath conifers and in the South-west under aspens. In southern California, it can be found under oak.

Comment: Activity suspected but not known. A spectacularly beautiful mushroom, Psilocybe aeruginosa is listed in most books as a Stropharia. Noordeloos (1995) proposed a new combination, placing this mushroom, more appropriately, into the genus Psilocybe, following the suggestions of Alexander Smith (1979). This mushroom has historically been reported as poisonous, perhaps because of its psilocybin content. (Some books still report it is poisonous, without providing elaboration or references.) Analyses of specimens from Washington found no psilocybin or psilocin (Beug and Bigwood 1982b). I know people who have eaten this species with no effects. In Europe, it is thought to be edible. Since the consumability of this species is questioned, caution is advised until the biochemistry of this species is studied further. See also Psilocybe caerulea (= Stropharia caerulea).

source - Paul Stamets "Psilocybin Mushrooms of the World"

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