Legend has it that women in Italy put deadly nightshade juice in their eyes to brighten them [source: Georgetown Pharmacology]. In fact, one of the common names for deadly nightshade is belladonna, which is Italian for "beautiful lady." Today, doctors rarely perform any type of eye surgery without using atropine, one of the poisons in deadly nightshade, to dilate the patient's pupils.
The name says it all.
Deadly nightshade, or Atropa belladonna, contains poisonous atropine and scopolamine in its stems, leaves, berries and roots.
Deadly nightshade is a perennial plant that grows between 2 and 4 feet (0.6 to 1.2 meters) tall. You'll recognize it by its dull, dark green leaves and bell-shaped purple, scented flowers, which bloom from mid-summer through early fall.
Deadly nightshade berries are green when they form and turn to a shiny black as they ripen. They're sweet and juicy, which makes them tempting to children. The plant requires rich, moist soil to thrive, and it grows wild in some areas of the world, but in the United States is limited to cultivation. Not all animals are affected by deadly nightshade. While it's deadly to humans and some animals, horses, rabbits and sheep can eat the leaves without harm, and birds feed on the berries.
The poisons contained in deadly nightshade affect the nervous system. Taken in sufficient doses, the deadly poison paralyzes nerve endings in the involuntary muscles of the body, such as the blood vessels, heart and gastrointestinal muscles.
Symptoms of deadly nightshade poisoning include dilated pupils, sensitivity to light, blurred vision, headaches, confusion and convulsions. As few as two ingested berries can kill a child, and 10 to 20 berries would kill an adult. Even handling the plant can cause irritation.