What more I will say about the Universal Edibility Test is that if it is being used to determine edibility, it must only be as an ultimate last resort if someone is starving and there are no other options. It is simply too unreliable to trust concerning whether a plant is edible or poisonous. Only in a last resort situation should anyone gamble with eating unknown plants.
Also, keep in mind what starvation actually is. Being "really hungry" is NOT the same thing as starving. After about 30 days without any food, you would be starving. And then, keep in mind that if you are in fact starving, as your mind begins to shut you out of the executive decision-making process, you will probably be inclined toward acting subconcsiously, so a real effort must be given to keeping the dangers of eating unknown plants, and thus the Universal Edibility Test, in mind.
Also, where there are plants, there are probably small critters. I would rather risk eating a bug than a poisonous plant.