This innocuous-looking greenery is one of the most feared plants in the world. Its sting is so agonizing that a slight brush to the hand from one of the leaves can make a person throw up from the pain.
Not that the leaves are the only dangerous part. Only the roots of the Gympie are free of the fine hairs that lodge in the skin and deliver the sting. Every subsequent moment of pressure on the hairs causes them to put out more poison into the skin. The pain feels like fire, and it lasts. As long as the hairs are embedded in the skin, the pain keeps coming. Stings from the Gympie cause the lymphatic system to go into overdrive. A person’s throat, armpits, and groin swell up and ladle on the pain as the lymph nodes expand.
Just being around the Gympie hurts. It sheds its hairs continuously. Scientists believe that the stinging hairs keep the ground clear so it can take advantage of those sunny gaps in the canopy. Botanists working in the field go into sneezing fits and get nose bleeds from standing near the plant. Botanists who handle hundred-year-old specimens of Gympie still get stung.
Through the years, a few people have had extensive encounters with the plant. One man, who fell into a bush during World War II, was strapped to a hospital gurney, screaming, for three weeks. Another got hit in the chest in the late 1990s. For two years, his chest hurt every time he took a cold shower.
https://io9.gizmodo.com/if-you-touch-this-plant-it-will-make-you-vomit-in-pure-1693770289
https://curiosity.com/topics/the-suicide-plant-has-the-most-painful-stingers-in-the-world-curiosity/