I suspect if humans ate an entire marijuana plant (as might a herbivore) they would probably walk off a cliff or sit in a pasture until the wolves got them.
Like many Drug Warrior suppositions, this one is wrong: "Along with other psychoactive cannabinoids, THC is a hydrophobic oil, meaning it is insoluble in water but soluble in lipids (oil/fat) and alcohol. Using either one of these to extract THC from cannabis is required to have the cooked product be psychoactive.[1] During preparation the cannabis or its extract must be heated sufficiently or dehydrated to cause decarboxylation of its most abundant cannabinoid, tetrahydrocannabinolic acid (THCA), into psychoactive THC." (emphasis added) - http://en.wikipedia.org/wiki/Cannabis_foods#Ingredients_and_effects
(Not that the effects you describe qualify as "toxic" anyway ...)
Like many Drug Warrior suppositions, this one is wrong:...blah blah blah blah blah...
You think someone can eat an entire marijuana plant and be functional? What are you smoking? Never mind.