Because that's what they are called. That's the way it's meant to be.mushrooms are funny.The word itself might have come from Old French ("moisseron"). Even in modern french there are quite a few...
Mushrooms from the genus psilocybe account for most magic mushrooms (i.e Psilocybe Cubensis, Psilocybe Mexicana etc). Any mushroom containing psilocybin, psilocin or baeocystin are referred to as...