It's Aliiiiiiiive! Oo, the colors!

It was lightning, we think, striking a large dead oak whose roots were entangled with the fungal mass, that made the Earth's largest living organism sentient. Think of a vegetal brain that weighs as much as Columbus, Ohio, and is more intelligent. Too late, we discovered its minions had infiltrated farm fields from California to Maine. Ergot poisoning simultaneously affected at least a third of the US population. The rest, if not history, is certainly colorful.