Specifically for those who came to this page looking for information on getting high:
You may usually assume that your psilocybin mushroom will be less intense than a hit of acid, but you will get fooled one day.
If you happen to eat a mushroom just prior to the time it throws its spores, you may be in for a shock. You can tell when a mushroom has thrown its spores by the dark circle on the ground underneath.
However, you cannot tell when they are 30 seconds away from doing so.
I'm speaking of the kind of mushrooms that grow in cow pies in the South; I believe the scientific name is Psilocybe semilanceata
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