@Sviatogor, maybe it is connected with some legend or story? Or maybe these mushrooms were more common on these lands than on others?
@Perun, when I was a kid I was collecting particular mushrooms that my family liked – so my mother told me which are to be taken, and which should be left. I do not like them myself, actually I hate mushrooms, but when was a kid I liked collecting them.
There was only a problem with poisonous one, similar to eatable mushroom. I don’t know how it is called in English, but we called it “szatan”.
By the way, the Vikings were eating fly agaric to go berserk, so even this one is not that much poisonous. Probably a matter of dosis.