Short answers, pulled from the story.
Albertus Magnus recorded the mushroom in his work De vegetabilibus before 1256. He noted that people called it the fly mushroom because they powdered it and sprinkled it into milk to kill flies.
Carl Linnaeus described the fungus from Småland in southern Sweden where he had lived as a child. He named it Agaricus muscarius in volume two of Species Plantarum published in 1753.
The oval spores measure nine to thirteen micrometers by six point five to nine micrometers. They do not turn blue with the application of iodine.
An active dose in adults is approximately thirty to sixty milligrams of ibotenic acid. This amount is typically about what one cap contains.
This prompted an FDA ban of their use in food products in December 2024. The Food and Drug Administration lists Amanita mushrooms as a poison and they are not approved as ingredients in food.