Nick Maclaren wrote:
Er, no. It doesn't say that at all. It says essentially what I
said. Not all plants have mycorrhiza, and many/most don't need
them in suitable soils.

I thought it was an occurence in any plant, it is a fungi after all,
with different patterns in distribution throughout the year so that
sometimes you can see it and sometimes you can't, which doesn't mean
it's not there. I thought it wasn't a matter of 'needing' it as such,
but increasing the amount of it so that the plant would benefit from it
to form more roots.