Psilocybe cyanescens has a hygrophanous pileus that is chestnut-brown when moist, fading to pale buff or slightly yellowish. Fresh material always bruises a bluish or blue-green color where damaged, and the staining is still visible after drying. It’s stem is white when undisturbed and bruises easily when damaged. Cap generally measures from 2-5 cm across, distinctly wavy in maturity. Lamellae adnate, light brown to dark purple brown in maturity, with lighter gill edges. An annulus is absent and the spore print is dark purple brown. Microscopically, this species is characterized by common clavate-mucronate pleurocystidia and smooth, elliptical spores which measure 9 – 12 × 6 – 8. The odor and taste is farinaceous.
According To Stamets, the chemical currently known as baeocystin (baeocystine) was incorrectly named. A misnomer occurred as a result of a mis-identified collection of what was actually Psilocybe cyanescens (and not Psilocybe baeocystis). Stamets proposed the chemical name Cyanescin as the new, corrected name.
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Also, see Guzman’s description of this species (page 334) here: http://mykoweb.com/...
Cybertruffle Link: http://www.cybertruffle.org.uk/...