It now appears that the mushroom cults are of great age and 
were once much more widespread. Archeological artefacts, now 
called “mushroom stones,” excavated in great numbers from 
highland Mayan sites in Guatemala, are dated conservatively at 
1000 B.C. Consisting of a stem with a human or animal face and 
crowned with an umbrella-like top, these icons indicate the 
existence of a sophisticated mushroom cult at least 3000 years 
ago (Schultes and Hofmann 1979). 
Perhaps the most important species employed in Mexican 
mushroom rites are Psilocybe aztecorum Heim, P. caerulescens, 
P. mexicana Heim, P. zapotecorum Heim, and Stropharia 
cubensis (Heim and Wasson 1959; Heim 1967). All of these have 
been found to contain a most extraordinarily psychoactive 
compound, psilocybin (XXIII)—an hydroxyindole alkylamine 
with a phosphorylic ester group: 4-phosphoryloxy-N,N-di- 
methyltryptamine, and sometimes the unstable derivative, psilo- 
cin (XXIV): 4-hydroxy-N,N-dimethyltryptamine. Psilocybin is 
the only indole compound known from the Plant Kingdom with 
a phosphoric acid radical and both psilocybin and psilocin are 
novel among indoles in having the hydroxy radical substituted 
in the 4-position (Schultes 1976a; Schultes and Hofmann 1979). 
Tryptophan is probably the biogenetic precursor of psilocybin 
(Hofmann et al. 1958, 1959; Hofmann and Troxier 1959; 
Hofmann and Tscherter 1960). 
O—R 
N N 
H CHY ~CH, 
XXIl PO,H 
XXIV H 
