Iris Cohen schreef
the identity of the mycorrhizal symbiont of an orchid species is
evidence for its taxonomic position within Orchidaceae.

Funny that Robert Dressler, the doyen of orchid taxonomy, has never even
mentioned it. What scientific studies or evidence do you have to back this
up? Can you give a specific example?
Iris,

+ + +
Actually I wrote:
You can even assign orchids to taxonomic groups depending on the mycorrhiza
they favor.

I imagine I could dig out the relevant publication, but not easy: this
author has too many publications about orchids to his name for me to narrow
it down quickly. I have little interest in orchids.

It sounded as if the story had been told many times, so likely anybody
following such matters will recognize it (the story involved a jacket).
PvR