penis envy is a strain of mushrooms. i supposedly had them once, and they were very potent. i tripped pretty good from like 2 grams.
well here's a n00b question: a strain is not a different species, correct? as in, there are several strains of the p. cubenis species (cubes), penis envy being one of them? what are some other cube strains then (even if their not more potent)? damn, that makes for a lot of mushrooms...
It doesn't matter the strain you pick, it's your substrate and environment that decides how potent a Cubensis is. They do vary a small bit, but not much.
Other strains of cubes include B+, john Allen, golden teachers, etc. And what 36fin5 said is pretty much true for the most part except with PE