Coo yes - Amanita muscaria without a doubt. It was this mushroom the
Norsemen took before going berserk.

Evidence?

Learned tomes on the subject. Dr. John Ramsbottom (Onetime Curator of
Dept. of Mycology, British Museum of Natural History) refers to it,
though cautiously, in Mushrooms and Toadstools in Collins' New
Naturalist series.

Was Ramsbottom there then?

Mary