The stinging nettle (Urtica ioica) is a herbaceous flowering plant, native to Europe, Asia, northern Africa, and North America, and is the best known member of the nettle genus Urtica. The plants have stinging hairs (trichomes), whose tips come off when touched, transforming the hair into a needle that will inject a cocktail of irritants: acetylcholine, histamine, 5-HT and possibly formic acid. This mix of poisons cause a sting or paresthesia from which the species derives its common name, as well as the colloquial name "7 minute stitch", burn nettle, burn weed, and burn hazel.