Thanks Space, it was an educated guess and I'd say not too far off the mark. Maybe just right for an introduction.
The few quantitative alkaloid studies on gyms (of which Gartz's studies on G.purpuratus are probably the best) have revealed lower alkaloid levels than the more potent psilocybe species, though the more strongly bluing gyms might yet hold some surprises.
A note of caution :- The gymnopilus genus is very closely related to the deadly Galerina genus so great care should be exercised in identification.
MJ, a very substantial paper could be written just clearing up the mess mycologists have made of this single taxon. Not only do we have G. purpuratus but also G. purpuratus var croceescens and G. purpuratus var purpuratus.
Grgurinovic regarded Cleland & Cheel (1918) Flammula purpureonitens and F. purpuratus as synonyms for G. mullaunius which in turn Rees made synonymous with G. purpuratus.
G. purpuratus is also regarded as a synonym for G. dilepis by some authorities. If the latter two species are indeed separate taxa then I predict G. dilepis to be active on its bluing characteristics.
Knowing how adventitious gym species can be and with limited data, I'm still unconvinced regarding a South American introduction at this point.
A few more snaps :- The third flush
, spiderweb-like cortina on mature pin, bluing at stem bases (smoky blue-black), and sporeprint (a very orange color under incandesent light).