us to the dark side of the plant world. >> i am amy stewart. i am the arthur of "wicked plants," the weeds that killed lincoln's mother and other botanical atrocities. with the screens fly trap, that is kind of where everybody went initially, you mean like that? i kind of thought, well, all it does is eat up bugs. that is not very wicked. so what? by wicked, what i mean is that they are poisonous, dangerous, deadly or immoral or maybe illegal or offensive or awful in some way. i am in the profession of going around and interviewing botanists, horticulturalists and plant scientists. they all seem to have some little plant tucked away in the corner of a greenhouse that maybe they weren't supposed to have. i got interested in this idea that maybe there was a dark side to plants. >> the white snake root. people who consumed milk or meat from a cow that fed on white snake root faced severe pain. milk sickness, as it was culled, resulted in vomiting, tremors, delirium and death. one of the most famous victims of milk sickness was nancy hangs lincoln.