Valu-nõgespuu äärmiselt ohtlik kõrvetus on teadaolevalt tapnud nii koeri, hobuseid kui ka inimesi. Kõiki taime osi peale juurte — selle südamekujulisi lehti, varsi ja vilju — katavad tillukesed, torkivad, süstlanõelakujulised karvad. Kõrvetadasaamiseks piisab taime kergest riivamisest. Selle käigus läbistab karv naha ja pritsib organismi valulist toksiini, mida nimetatakse moroidiiniks.
The nettle family is full of stinging plants, but none is quite as aggressive as the gympie gympie (Dendrocnide moroides). One of six stinging trees native to Australia (because of course) and also found in Indonesia, the gympie gympie is one of the most dangerous plants in the world. The stinging leaves trigger an intense allergic reaction in its victims, sometimes even causing anaphylactic shock. The sting can cause excruciating, debilitating pain for months; people have variously described it as feeling like they are being burned by acid, electrocuted, or squashed by giant hands.
