Grim Reaper: Rhubarb! Get your fresh rhubarb—the reddest fruit in town!
Alton Brown: Um, excuse me, um, isn’t rhubarb in the same botanical family as buckwheat and sorrel, and therefore, in fact, a vegetable?
GR: Yeah, sure. Whatever. Makes a killer pie, though ... I mean, delicious. Try some.
AB: Er, maybe, maybe, in a minute.
You know, rhubarb, which in Latin, roughly translates to "root of the barbarians", was originally used as a medicinal product—a hepatic stimulant, in fact—until about the 18th century, when it finally became a culinary ingredient. Why the long wait? Oh, I don’t know ...
AB: ... could it be because rhubarb is poison?!?
GR: Only if you eat it.
Well, in this case, the reaper-y device there comes in the form of oxalic acid, which besides being a flavorant, is also a darn good bleach and rust remover.
GR: Ahhh, oxalic acid. It’s one of my favorites. Right up there with hemlock and old "Three’s Company" reruns. Try some.
AB: Oh, what the heck. [eats a sample of rhubarb, then gags, and spins out of view of the camera.]
GR: Another clueless pedestrian lured in by the ruby-hued stalk of doom. Heh, heh, heh, heh ...
AB: [now recovered] You know, actually, all the poison is in the leaves. That just really tastes lousy, raw.
GR: Eh, well, can’t blame a Reap for trying.
AB: ‘Suppose not.
GR: See you next week. Just kidding. Or am I? Heh, heh, heh, heh ... [floats off camera]