If Neville Longbottom ever turned evil, and decided to use his botanical powers to advance his wicked agenda, this is the plant he would use. Dumbcane will take away your power of speech, and then it will kill you.
Like oleander and poinsettias, this Dieffenbachia picta has become a fixture of yards and houses. It probably shouldn't be. It has some very unpleasant effects, if chewed by children or pets. These effects are summed up by its unofficial nickname, dumbcane. It's also called the Mother-in-Law plant, though whether it was meant to be applied to a mother-in-law, or earned the name because it shared a mother-in-law's ability to render those around her speechless, is anyone's guess.
Dumbcane leaves contain unpleasant things called idioblasts, which, when damaged, shoot even more unpleasant things called raphides. Raphides are crystals of calcium oxalate, shaped like barbed spikes. Either the chewing motion or the agitation of the idioblast cells drive the raphides into the soft tissue in your mouth and parts beyond, lacerating all the way. And that's just phase one. Dumbcane contains an enzyme like the stuff in scorpion venom. That enzyme runs through special grooves in the raphides, and hits the tissue. This numbs the tissue, and gives the plant its name. Anyone who takes a bite knows they're in pain, but can't get their numbed mouths and tongues to tell anyone about their distress.
What's interesting is, as far as I can tell, there is no nicer name for dumbcane, and yet it's a common houseplant. Who looks around a plant nursery, at the violets and roses and birds-of-paradise and snowdrops and thinks, "I think I'll take the dumbcane. Got a good feeling about it."
[Via Plant of the Week.]