We are all now aware of the toxic nature of the Arali flower (Nerium Oleander). Apart from Arali, here are some other flowers found in our region that are lethal in nature. Allamanda cathartica: A beautiful flowering shrub with yellow flowers, but all parts of the plant are poisonous if ingested and can cause serious illness or death. Cascabela thevetia: Also known as the Yellow Oleander, this plant is highly toxic and all parts can be fatal if ingested. Dieffenbachia seguina: Commonly known as