This document lists the top 10 most poisonous plants, including the Nerium Oleander and Water Hemlock which can cause death within minutes of ingestion, as well as the Rosary Pea where a single pea or seed can prove fatal. Other poisonous plants mentioned are Deadly Nightshade, Castor Oil Plant, English Yew, White Snakeroot, Aconite, Jimsonweed, and Machineel, several of which were used for their toxic properties throughout history and can severely harm or kill humans and animals upon contact with or consumption of their parts.