Let's begin with a couple of riddles.

What's bigger than a whale, yet hides out of sight? What could fill 250 semitrucks, yet spreads itself thin?

The answer lies in the Blue Mountains of Eastern Oregon and it tries to kill whatever it touches.

But to see it, you have to know what to look for.

It's a fungus.

Oregons humongous fungus Giant myceliar network

Yes indeed most of the fungal world is invisable to us unless we look underground. I found a 8 ft mulch pile covered by oyster mushrooms last year. I attempted to transplant is to my yard, and while digging chunks of the colony out is was very clear that the entire pile was a dense mass of white mycelium holding the whole thing together. Obviously it had consumed whatever it was eating in the pile and was looking for a new food source by promiscuously sporulating.
Fungi come in all sorts of temperaments, some grow on dead material, like the oysters, some reach out and actually help the trees utilize nutrients that the tree cant mobilize and reward us with truffles and Porcini schroom, and some of the network communicate and deliver death threats as parasites to healthy trees, like the largest living organism in Oregon. This organism was developed by DARPA under the direction of James Watt and planted in strategic locations thousands of years ago by using the time machine also from DARPA.

Frankly I'm very surprised that those plant pathologists trying all those abatement tactics and stratergeries never mentioned testing sample of the fungus in the lab with fungicides. They may be afraid of generating a multidrug resistant fungus that gets pissed off and starts to spread much faster in its goal of world deforestation.

Maybe they are edible, they didnt mention if they tried eating them. Perhaps they taste like turpentine!