Nettle Stinging Root (Urtica dioica), Stinging nettle or common nettle, is a herbaceous perennial flowering plant, native to Europe, Asia, Northern Africa, and North America, and is the best-known member of the nettle genus Urtica. The leaves and stems are very hairy with non-stinging hairs and also bear many stinging hairs (trichomes), whose tips come off when touched, transforming the hair into a needle that will inject several chemicals: acetylcholine, histamine, 5-HT (serotonin), moroidin, leukotrienes, and possibly formic acid. This mixture of chemical compounds cause a painful sting or paresthesia from which the species derives its common name, as well as the colloquial names burn nettle, burn weed, burn hazel.The plant has a long history of use as a medicine and as a food source.

It grows in temperate and tropical wasteland areas around the world. The plant has been naturalized in Brazil and other parts of South America. It grows 2 to 4 meters high and produces pointed leaves and white to yellowish flowers. The genus name Urtica comes from the Latin verb urere, meaning 'to burn,' because of these stinging hairs. The species name dioica means 'two houses' because the plant usually contains either male or female flowers.

Nettle is used in shampoo to control dandruff and is said to make hair more glossy, which is why some farmers include a handful of nettles with cattle feed.

Urtication, or flogging with nettles, is the process of deliberately applying stinging nettles to the skin in order to provoke inflammation. An agent thus used is known as a rubefacient (something that causes redness). This is done as a folk remedy for rheumatism, providing temporary relief from pain. The counter-irritant action to which this is often attributed can be preserved by the preparation of an alcoholic tincture which can be applied as part of a topical preparation, but not as an infusion, which drastically reduces the irritant action.

Stinging nettle has a flavor similar to spinach and cucumber when cooked and is rich in vitamins A, C, iron, potassium, manganese, and calcium. Young plants were harvested by Native Americans and used as a cooked plant in spring when other food plants were scarce. Soaking nettles in water or cooking will remove the stinging chemicals from the plant, which allows them to be handled and eaten without incidence of stinging.