Pileus (Cap): The cap ranges in shape from conical to bell-shaped to convex, reaching diameters of 0.7%u20133 in (18%u201376 mm), although a range of 1%u20132.5 cm (0.4%u20131.0 in) is most usual. It has a long, sharp papilla that is up to 4 mm (0.16 in). The cap surface is smooth, somewhat sticky when wet, and often has ridges extending halfway to the center of the cap. Its color is reddish brown to orangish brown to yellowish, and it is hygrophanous, fading when dry to a straw or fulvous color.The flesh in the cap is whitish, but more yellow in the stem.
Lamellae (Gills): The brownish gills have an adnate to adnexed attachment to the stem; mature gills become purplish black because of the spores.
Stipe (Stem): The hollow stem measures 50 to 90 mm (2.0 to 3.5 in) long by 1%u20133 mm thick. It is roughly equal in width throughout its length or slightly thicker at the base, and sometimes twisted. A thin rudimentary cortina-like partial veil covers the gills of immature fruit bodies, but it is fragile and disappears soon after the cap expands.
Microscopic features: The spore print is dark purplish brown. Spores are rhomboid or nearly so in face view, and more or less ellipsoid when viewed from the side. They are thick-walled, with dimensions of 6.5%u20134%u20135.6 um, and feature a broad germ pore. The basidia (spore-bearing cells) are usually four-spored, hyaline (translucent), roughly cylindrical or with a central constriction, and measure 12%u201322 by 5.5%u20139 um. Pleurocystidia (cystidia on the gill face) are relatively abundant; they are ventricose (swollen), club-shaped or irregularly shaped, measuring 16%u201336 by 8%u201312 um. The cheilocystidia (cystidia on the gill edge) are also abundant. They are 19%u201335 by 4.4%u20136.6 um, lageniform (flask-shaped), narrowing into a long neck with a width of 1%u20133 um, and either acute or somewhat capitate (ending in a roughly globular tip). Clamp connections are present in the hyphae.
Season: June through December.
Habitat and Distribution: The species is found in Mexico, where it grows singly or in small groups in clayey soils in subtropical coffee plantations, and from Colombia and Brazil in South America
Growth Habit: Solitary to cespitose.
Bruising: As is characteristic of psilocybin mushrooms, all parts of the fruit body bruise blue when handled or injured.
Other Notes: The species was first described scientifically by French mycologist Roger Heim in 1958. It was one of several species described and illustrated in the popular American weekly magazine Life ("Seeking the Magic Mushroom"), in which R. Gordon Wasson recounted the psychedelic visions that he experienced during the divinatory rituals of the Mixtec people, thereby introducing psilocybin mushrooms to Western popular culture; it was however, mislabeled as Psilocybe zaptecorum. Similarly, Psilocybe specialist Gaston Guzman suggests that P. zapotecorum, as described by Rolf Singer in 1958, is misidentified as it agrees well with the type of P. hoogshagenii. The species Psilocybe caerulipes var. gastonii, described by Singer in 1958, is a synonym of P. hoogshagenii. The species is named in honor of American anthropologist Searle Hoogshagen, who helped Heim and Wasson in their search for entheogenic mushrooms in Mexico. The mushroom is known locally by several common names. In Spanish, it is called los ninos or los Chamaquitos ("the little boys"), in Mazatec as pajaritos de monte ("little birds of the woods"), in Nahuatl as cihuatsinsintle or teotlaquilnanacatl ("divine mushroom that describes or paints"), and in Mixe as Atka:t ("judge") or na.shwi.n mush ("mushrooms of the earth").
The variety P. hoogshagenii var. convexa was described by Guzman in 1983 to account for mushrooms without an acute papilla that were otherwise roughly the same as the type variety. Psilocybe semperviva, described by Heim and Roger Cailleux in 1958, was later determined by Guzman to be synonymous with P. hoogshagenii var. convexa. The varietal epithet convexa refers to the convex shape of the cap. The mushroom contains the psychedelic compounds psilocybin and psilocin, and all parts will stain blue or bluish black when handled or injured. P. hoogshagenii is used for divinatory purposes by some indigenous groups in Mexico. Links: Psilocybe hoogshagenii -MushroomObserver