Significations et usages de Urtica

From Wikipedia, the free encyclopedia

Nettle is the common name for between 30-45 species of flowering plants of the genus Urtica in the family Urticaceae, with a cosmopolitan though mainly temperate distribution. They are mostly herbaceous perennial plants, but some are annual and a few are shrubby.

The most prominent member of the genus is the stinging nettle Urtica dioica, native to Europe, Africa, Asia, and North America. The genus also contains a number of other species with similar properties, listed below. However, a large number of species names that will be encountered in this genus in the older literature (about 100 species have been described) are now recognized as synonyms of Urtica dioica. Some of these taxa are still recognized as subspecies.

Most of the species listed below share the property of having stinging hairs, and might be expected to have similar medicinal uses to the stinging nettle. The stings of Urtica ferox, the ongaonga or tree nettle of New Zealand, have been known to kill horses, dogs and at least one human.^[1]

The nature of the toxin secreted by nettles is not settled. The stinging hairs of most nettle species contain formic acid, serotonin and histamine; however recent studies of Urtica thunbergiana (Fu et al., 2006) implicate oxalic acid and tartaric acid rather than any of those substances, at least in that species.

Species of nettle

Species in the genus Urtica, and their primary natural ranges, include:

• Urtica angustifolia Fisch. ex Hornem. 1819. China, Japan, Korea.
• Urtica ardens. China.
• Urtica atrichocaulis. Himalaya, southwestern China.
• Urtica atrovirens. Western Mediterranean region.
• Urtica cannabina L. 1753. Western Asia from Siberia to Iran.
• Urtica chamaedryoides (heartleaf nettle). Southeastern North America.
• Urtica dioica L. 1753 (stinging nettle or bull nettle). Europe, Asia, North America.
• Urtica dubia (large-leaved nettle). Canada.
• Urtica ferox (ongaonga or tree nettle). New Zealand.
• Urtica fissa. China.
• Urtica galeopsifolia Wierzb. ex Opiz, 1825, (fen nettle or stingless nettle). Europe. (Often considered a subspecies of Urtica dioica.)
• Urtica gracilenta (mountain nettle). Arizona, New Mexico, west Texas, northern Mexico.
• Urtica hyperborea. Himalaya from Pakistan to Bhutan, Mongolia and Tibet, high altitudes.
• Urtica incisa (scrub nettle). Australia.
• Urtica kioviensis Rogow. 1843. Eastern Europe.
• Urtica laetivirens Maxim. 1877. Japan, Manchuria.
• Urtica linearifolia. Creeping or Swamp Nettle. New Zealand.
• Urtica mairei. Himalaya, southwestern China, northeastern India, Myanmar.
• Urtica membranacea. Mediterranean region, Azores.
• Urtica morifolia. Canary Islands (endemic).
• Urtica parviflora. Himalaya (lower altitudes).
• Urtica pilulifera (Roman nettle). Southern Europe.
• Urtica platyphylla Wedd. 1856-1857. China, Japan.
• Urtica pubescens Ledeb. 1833. Southwestern Russia east to central Asia.
• Urtica rupestris. Sicily (endemic).
• Urtica sondenii (Simmons) Avrorin ex Geltman, 1988. Northeastern Europe, northern Asia.
• Urtica taiwaniana. Taiwan.
• Urtica thunbergiana. Japan, Taiwan.
• Urtica triangularisa
• Urtica urens L. 1753 (dwarf nettle or annual nettle). Europe, North America.

The family Urticaceae also contains some other plants called nettles that are not members of the genus Urtica. These include the wood nettle Laportea canadensis, found in eastern North America from Nova Scotia to Florida, and the false nettle Boehmeria cylindrica, found in most of the United States east of the Rockies. As its name implies, the false nettle does not sting.

Similar plants

Other members of other genera in the Urticaceae, with powerful stings:

• Giant stinging tree (Dendrocnide excelsa)
• Gympie (Dendrocnide moroides )
• Wood Nettle (Laportea canadensis )
• Nettle Tree (Urera baccifera )

There are a number of other plants whose common names include the word Nettle but which are neither part of the Urticacea nor do they sting. These include:

• Dead-nettle (Lamium spp.) and hedge-nettle (Stachys spp.) which are in the Lamiaceae or mint family.
• Devil's nettle, which is another name for yarrow.
• Carolina horsenettle (Solanum carolinense) in the Solanaceae.
• Spurge-nettle (Cnidolscolus stimulosus) in the Euphorbiaceae.

There are also plants which can produce stinging sensations but which are unrelated to the Urticaceae [1]

• Dumb cane (Dieffenbachia spp., Araceae)
• Cowhage (Mucuna pruriens, Fabaceae)
• Bull Nettle or Spurge Nettle (Cnidoscolus stimulosus, Euphorbiaceae)
• Ciega-vista (Croton ciliato-glandulosus, Euphorbiaceae)
• Stinging Spurge (Jatropha urens L., Euphorbiaceae)
• Noseburn (Tragia spp., Euphorbiaceae)
• Nilgiri Nettle (Girardinia leschenaultiana )

Uses and medical properties of nettles

For medicinal, food and other uses please see Stinging nettle. Much historical evidence of use of nettles in medicine, folk remedies, cooking and fiber production relate to one species - Urtica dioica, but a fair amount also refers to the use of Urtica urens, the small nettle, which is preferred because it has more stinging hairs per leaf area than the more common species. It may be inappropriate and probably inaccurate to assume that all nettles exhibit similar properties in all cases, but where an action can be attributed to principles found in the species, such as histamine, choline, formic acid and silica, a rational basis for their use is still available. However, the fact that a medical action can be attributed to a single constituent does not imply that the entire plant will have the same action.

Safety

Though the fresh leaves can cause painful stings and acute urticaria, these are rarely seriously harmful (but see remarks in the introductory section regarding the U. ferox, ongaonga or tree nettle of New Zealand). Otherwise most species of nettles are extremely safe and some are even eaten as vegetables after being steamed.^{[citation needed]}

See also

• Lamium, the "deadnettles".
• Nettles in folklore
• Mopiko, a nettle rash cream.
• Rumex, Dock leaves for sting easement and nullification of longer term effects.
• Poison oak
• Poison ivy
• Poison sumac

Footnotes

References

• Anderberg, Kirsten (2005). Folk uses and history of medicinal uses of nettles. Nettles, Nettles, Everywhere
• Chrubasik S, Enderlein W, Bauer R, Grabner W. (1997). Evidence for the antirheumatic effectiveness of herba Urticae dioicae in acute arthritis: A pilot study. Phytomedicine 4: 105-108.
• Dathe G, Schmid H. (1987). Phytotherapy for benign prostatic hyperplasia (BPH): Double-blind study with extract of root of urtica (ERU). Urologe B 27: 223-226 [in German].
• Fu H Y, Chen S J, Chen R F, Ding W H, Kuo-Huang L L, Huang R N (2006). Identification of oxalic acid and tartaric acid as major persistent pain-inducing toxins in the stinging hairs of the nettle, Urtica thunbergiana. Annals of Botany (London), 98:57-65. Abstract
• Holden, Margaret (1948). "An alkali-producing mechanism in macerated leaves". Biochemical Journal 42 (3): 332–336. http://www.pubmedcentral.gov/picrender.fcgi?artid=1258718&blobtype=pdf. Retrieved 2006-09-25. 
• Kirchhoff HW. (1983). Brennesselsaft als Diuretikum. Z. Phytother. 4: 621-626 [in German].
• Krzeski T, Kazón M, Borkowski A, et al. (1993). Combined extracts of Urtica dioica and Pygeum africanum in the treatment of benign prostatic hyperplasia: double-blind comparison of two doses. Clinical Therapy 15 (6): 1011-1020.
• Mittman, P. (1990). Randomized, double-blind study of freeze-dried Urtica dioica in the treatment of allergic rhinitis. Planta Med 56: 44-47.
• Randall C, Randall H, Dobbs F, et al. (2000). Randomized controlled trial of nettle sting for treatment of base-of-thumb pain. J. Roy. Soc. Med. 93: 305-309. reported online in British Medical Journal
• Weigend M, Luebert F. (2009). Weeding the nettles I: Clarifying species limits in perennial, rhizomatous Urtica (Urticaceae) from southern and central Chile and Argentina. Phytotaxa 2: 1-12.
• Yarnell E. (1998). Stinging nettle: A modern view of an ancient healing plant. Alt. Compl. Therapy 4: 180-186 (review).
• Healthy Life Magazine, Inc. (June 2007) p.78

External links

• Nature's Secret Larder
• Flora Europaea: Urtica
• Flora of North America: Urtica
• Flora of China: Urtica
• Plants for a Future database search for Nettle
• HerbalGram and American Botanical Council website search for Urtica
• Historical & Current Uses for Nettles