Poisonous silence: the dumb cane

Sap from the dumb cane plant that gets into a human mouth will make the tongue swell, causing speechlessness in adults and sometimes killing children. This effect was used by slave-owners to torture unruly slaves working in Caribbean sugar plantations.
Extract from the leaves also attacks the body’s sex cells. In 1941, Heinrich Himmler, then head of the SS in Nazi Germany, considered using the dumb cane to sterilise war prisoners. The plan failed due the difficulty of shipping enough plants over from their natural home in Central America.
Despite its violent history and the dangerous chemicals found in its leaves and stems, the dumb cane is a very popular houseplant.