Urtica dioica, often known as common nettle, burn nettle, stinging nettle, nettle leaf, or just a nettle or stinger, is a herbaceous perennial flowering plant in the family Urticaceae. Originally native to Europe, much of temperate Asia and western North Africa, it is now found worldwide. The species is divided into six subspecies, five of which have many hollow stinging hairs called trichomes on the leaves and stems, which act like hypodermic needles, injecting histamine and other chemicals that produce a stinging sensation upon contact ("contact urticaria", a form of contact dermatitis). The plant has a long history of use as a source for traditional medicine, food, tea, and textile raw material in ancient (such as Saxon) and modern societies.
Description Urtica dioica is a dioecious, herbaceous, and perennial plant. It grows to 0.9 to 2 metres (3 to 7 feet) tall in the summer and dying down to the ground in winter. It has widely spreading rhizomes and stolons, which are bright yellow, as are the roots. The soft, green leaves are 3 to 20 centimetres (1 to 6 in) long and are borne oppositely on an erect, wiry, green stem. The leaves have a strongly serrated margin, a cordate base, and an acuminate tip with a terminal leaf tooth longer than adjacent laterals. It bears small, greenish or brownish, numerous flowers in dense axillary inflorescences. The leaves and stems are very hairy with non-stinging hairs, and in most subspecies, also bear many stinging hairs (trichomes or spicules), whose tips come off when touched, transforming the hair into a needle that can inject several chemicals causing a painful sting or paresthesia, giving the species its common names: stinging nettle, burn-nettle, burn-weed, or burn-hazel.
Taxonomy
Credit for the scientific naming of Urtica dioica is given to Carl Linnaeus, who published it in Species Plantarum in 1753. The taxonomy of Urtica species is confused, and sources are likely to use a variety of systematic names for these plants. Until 2014 there was broad consensus that the nettles native to the Americas, now classified as Urtica gracilis, were subspecies of U. dioica. However, in that year the paper "Weeding the Nettles II" was published in the journal Phytotaxa demonstrating the genetic distinctness of New World nettles. As of 2023 Plants of the World Online (POWO) recognises U. gracilis as a distinct species while the USDA Natural Resources Conservation Service PLANTS database continues to list it as U. dioica subsp. gracilis, as does the Flora of North America. As of 2023 POWO recognises 11 subspecies or varieties of U. dioica:
Urtica dioica subsp. afghanica Chrtek, from southwestern and central Asia, sometimes has stinging hairs or is sometimes hairless. Urtica dioica subsp. dioica (European stinging nettle), from Europe, Asia, and northern Africa, has stinging hairs. Urtica dioica subsp. gansuensis C.J.Chen, from eastern Asia (China), has stinging hairs. Urtica dioica var. glabrata (Clem.) Asch. & Graebn. Urtica dioica var. hispida (Lam. ex DC.) Tausch ex Ott Urtica dioica var. holosericea Fr., in many sources as Urtica angustifolia. Urtica dioica subsp. kurdistanica Chrtek Urtica dioica subsp. pubescens (Ledeb.) Domin, in many sources as U. dioica subsp. galeopsifolia (fen nettle or stingless nettle), from Europe, does not have stinging hairs. Urtica dioica var. sarmatica Zapał. Urtica dioica subsp. sondenii (Simmons) Hyl. Urtica dioica subsp. subinermis (R.Uechtr.) Weigend
Etymology Urtica is derived from a Latin word meaning 'sting'. Dioica (δίοικος) is derived from Greek, meaning 'of two houses' (having separate staminate and pistillate plants; dioecious).
Distribution and habitat
U. dioica is considered to be native to Europe, much of temperate Asia and western North Africa. It is abundant in northern Europe and much of Asia, usually found in the countryside. It is less widespread in southern Europe and north Africa, where it is restricted by its need for moist soil, but is still common. It has been introduced to many other parts of the world. In North America, it is widely distributed in Canada and the United States, where it is found in every province and state except for Hawaii, and also can be found in northernmost Mexico. It grows in abundance in the Pacific Northwest, especially in places where annual rainfall is high. The European subspecies has been introduced into Australia, North America and South America. In Europe, nettles have a strong association with human habitation and buildings. The presence of nettles may indicate the site of a long-abandoned building, and can also indicate soil fertility. Human and animal waste may be responsible for elevated levels of phosphate and nitrogen in the soil, providing an ideal environment for nettles.
Ecology
Nettles are the larval food plant for several species of butterflies in the Nymphalidae family, such as the peacock butterfly, comma (Polygonia c-album), and the small tortoiseshell. It is also eaten by the larvae of some moths including angle shades, buff ermine, dot moth, the flame, the gothic, grey chi, grey pug, lesser broad-bordered yellow underwing, mouse moth, setaceous Hebrew character, and small angle shades. The roots are sometimes eaten by the larva of the ghost moth (Hepialus humuli). It is a known host to the pathogenic fungus Phoma herbarum. Stinging nettle is particularly found as an understory plant in wetter environments, but it is also found in meadows. Although nutritious, it is not widely eaten by either wildlife or livestock, presumably because of the sting. It spreads by abundant seeds and also by rhizomes, and is often able to survive and re-establish quickly after fire.
Cultivation
Field
Sowing and planting Three cultivation techniques can be used for the stinging nettle: 1) direct sowing, 2) growing seedlings in nurseries with subsequent transplantation and 3) vegetative propagation via stolons or head cuttings.
… excerpt ends here. Continue reading the full article.
