In the vast majority of cases the mycelium is harmless
to live plants, the common exception being "honey fungus".[/quote]

Hi Kay & Tom,
Weekend again and time to tackle this strange white root like stuff.
Well it doesn't sound like honey fungus and Kay makes a good point. Our woods would be devastated if it attacked living plants/trees.
I'm going with the only attacking stressed or dying plants.

Thanks for your help with this. Any further thoughts would be appreciated but I'm feeling a lot more optimistic about it.
Thanks again,
Penny