In a word, my belief is that Soma is the Divine Mushroom of Immortality, and that in the early days of our culture, before we made use of reading and writing, when the RgVeda was being composed, the prestige of this miraculous mushroom ran by word of mouth far and wide throughout Eurasia, well beyond the regions where it grew and was worshipped. (Chapter 1: The Problem, page 9)
There is I think an inference that we may draw: a plant with properties that could be plausibly named the Herb of Im...