Nettle

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"Nettles" redirects here. For people with this name, see Nettles (surname).
For other uses, see Nettle (disambiguation).
Nettle
Stinging nettle (Urtica dioica)
Scientific classification
Kingdom: Plantae
Division: Magnoliophyta
Class: Magnoliopsida
Order: Urticales
Family: Urticaceae
Genus: Urtica
L., 1753
Species

See text.
detail of flowering stinging nettle

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, north 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.

Contents

[edit] Species of nettle

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

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.

[edit] Similar plants

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

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:

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

[edit] Uses and medical properties of nettles

Close-up detail of the stinging hairs.

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.

[edit] Safety

Accuracy dispute
 This article appears to contradict the article Nettles in folklore. Please see discussion on the linked talk page. Please do not remove this message until the contradictions are resolved.

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]

[edit] See also

[edit] Footnotes

  1. ^ Connor, H.E. (1977). The Poisonous Plants in New Zealand. New Zealand Department of Scientific and Industrial Research Bulletin 99. ISSN 0077-916X

[edit] 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
  • 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

[edit] External links

Retrieved from "http://en.wikipedia.org/wiki/Nettle"