These mushrooms first gained recognition in the early 1900s when they appeared in local garden beds and several instances of accidental intoxication's occurred when individuals reported to the ER for suspected mushroom poisoning. One woman said that if this is the way one died from mushroom poisoning, then she was all for it.
So in the early 1900s, this species which at first was identified as Panaeolus venonosus (Implying poisonous Panaeolus) it was labeled as the 'Weed' fungi. In commercial mushroom farms in Pennsylvania, and the NE coastal region, they had to hire extra mushroom harvesters to 'weed out' that mushroom from the beds of Agaricus campestris and Agaricus bisporus. The two primary species of edible grocery store mushrooms.
Here then is my paper from Heads Magazine (the Canadian version of Head Magazine).
Page 25 is the page full of shroom photos.
mjshroomer