The plant Atropa belladonna has the most poisonous flowers in the world. Native to Western Asia, Europe and North Africa, Atropa belladonna, also called Devil's Berries or Deadly Nightshade, belongs to the family Solanaceae.

Atropa belladonna has delicate dull purple flowers and its leafs contain high concentrations of alkaloid toxins which can disrupt the nervous system. Since its so poisonous that one single leaf can kill a healthy adult, the ancient Romans used it as a poison. It is a well known story that both the wife of Claudius and the wife of Emperor Augustus used Atropa belladonna to kill contemporaries.