Raffi at 13:15, 4 April 2007

2007-04-04T13:15:20Z

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{{Taxobox
| color = lightgreen
| name = Stinging nettle
| image = Brennnessel 1.JPG
| image_width = 240px
| image_caption = ''Urtica dioica'' subsp. ''dioica''
| regnum = [[Plant]]ae
| divisio = [[Flowering plant|Magnoliophyta]]
| classis = [[Magnoliopsida]]
| ordo = [[Rosales]]
| familia = [[Urticaceae]]
| genus = ''[[Urtica]]''
| species = '''''U. dioica'''''
| binomial = ''Urtica dioica''
| binomial_authority = [[Carolus Linnaeus|L.]]
}}

The '''stinging nettle''' (''Urtica dioica'') 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 [[taxonomy]] of stinging nettles in the genus ''Urtica'' has been confused, and older sources are likely to use a variety of systematic names for these plants. Formerly, more species were recognised than are now accepted. However, there are at least five clear [[subspecies]], some formerly classified as separate species:
*''U. dioica'' subsp. ''dioica'' (European stinging nettle). Europe, Asia, northern Africa.
*''U. dioica'' subsp. ''afghanica''. Southwestern and central Asia.
*''U. dioica'' subsp. ''gansuensis''. Eastern Asia (China).
*''U. dioica'' subsp. ''gracilis'' (Ait.) Selander (American stinging nettle). North America.
*''U. dioica'' subsp. ''holosericea'' (Nutt.) Thorne (hairy nettle). North America.

Other species names formerly accepted as distinct by some authors but now regarded as [[synonymy|synonyms]] of ''U. dioica'' include ''U. breweri, U. californica, U. cardiophylla, U. lyalli, U. major, U. procera, U. serra, U. strigosissima, U. trachycarpa'', and ''U. viridis''. Other vernacular names include tall nettle, slender nettle, California nettle, jaggy nettle, burning weed, and bull nettle (a name shared by ''[[Cnidoscolus texanus]]'' and ''[[Solanum carolinense]]'').

[[Image:Euro stinging nettle.jpg|thumb|left|A young European stinging nettle]]
Stinging nettles are an [[herbaceous]] [[perennial]], growing to 1-2 [[metre|m]] tall in the summer and dying down to the ground in winter. It has very distinctively yellow, widely spreading roots. The soft green [[leaf|leaves]] are 3-15 [[centimetre|cm]] long, with a strongly serrated margin, a cordate base and an acuminate tip. Both the leaves and the stems are covered with brittle, hollow, silky hairs that were formerly thought to contain [[formic acid]] as a defence against grazing animals. Recent research has revealed the cause of the sting to be from three chemicals - a [[histamine]] that irritates the skin, [[acetylcholine]] which causes a burning sensation and [[serotonin]], that encourages the other two chemicals (Elliott 1997). Bare skin brushing up against a stinging nettle plant tends to break the delicate defensive hairs and release the trio of chemicals, usually resulting in a temporary and painful skin [[rash]] similar to [[poison ivy]], though the nettle's rash and duration are much weaker. It is possible to evade the sting by touching the middle of the [[leaf]] or by stroking in the same direction as the hairs.

Stinging nettles are abundant in northern Europe and much of Asia, usually found in the countryside. It is less gregarious in southern Europe and north Africa, where it is restricted by its need for moist soil. 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 [[South Carolina]]{{Fact|date=March 2007}}, and also can be found in northernmost [[Mexico]]. In North America the stinging nettle is far less common than in northern Europe. The European subspecies has been introduced into North America as well as [[South America]].

In the [[United Kingdom|UK]] stinging nettles have a strong association with human habitation and buildings. The presence of nettles may indicate that a building has been long abandoned. Human and animal waste may be responsible for elevated levels of phosphate in the soil, providing an ideal environment for stinging nettles. This seems particularly evident in [[Scotland]] where the sites of [[croft (land)|croft]]s razed to the ground during the [[Highland Clearances]] can still be identified.

==Uses==
[[Image:Urtica dioica.JPG|thumb|left|Detail of flowering stinging nettle]]
Stinging nettle has many uses. It is used by many different cultures for a wide variety of purposes in [[herbal medicine]]. Cooking, crushing or chopping disables the stinging hairs. Stinging nettle leaves are tasty and high in nutrients. The young leaves are edible and make a very good [[leaf vegetable|pot-herb]]. The leaves are also dried and may be then be used to make a [[tisane]], as can also be done with the nettle's flowers.

Nettle stems contain a [[bast fibre]] which has been traditionally used for the same purposes as [[linen]], and is produced by a similar [[retting]] process.

==Home remedies==
Several [[Home remedy|folk remedies]] exist for the sting, with disputed effectiveness:

* Juice from the crushed leaf of dock (''[[Rumex]]'' spp.), which commonly grows in association with nettles, rubbed into the area helps.
* Both species of [[Jewelweed]] (''[[Impatiens capensis]]'' and ''[[Impatiens pallida]]'') can and have been used as preventatives and palliatives for Stinging Nettle rash. To do so, one can take the whole plant, crush it into a ball, and rub it onto the exposed area, or one can crush some jewelweed stems in a container, and then use a cotton ball to soak up the juice. The anti-inflammatory/fungicidal chemical in this plant is [[2-methoxy-1,4-naphthoquinone]].<ref>[http://www.jbc.org/cgi/reprint/174/1/335.pdf Isolation and Antifungal Action of Naturally Occurring 2-methoxy-1,4-Naphthoquinone]</ref>
* Rubbing the underside of a [[fern]] leaf (which contains its spore pods or [[sorus|sori]]) on the afflicted area.
* [[Urination|Urinating]] on the affected area, as the [[ammonia]]c content of urine helps counteract the sting (Thiselton-Dyer 1889).
* Immediately rubbing mud on the affected area and allow it to dry before brushing it clean.
* Even quickly washing the affected area can help.
* A simple piece of ice can help relieve itchiness

==Influence on language and culture==
[[Image:Illustration Urtica dioica0.jpg|thumb|right|''Urtica dioica'' from Thomé, ''Flora von Deutschland, Österreich und der Schweiz'' 1885]]
In [[England]] the stinging nettle is the only common stinging plant, and has found a place in several [[figure of speech|figures of speech]] in the [[English (language)|English]] language. To "nettle" someone is to annoy them. [[William Shakespeare|Shakespeare]]'s [[Hotspur]] urges that "out of this nettle, danger, we grasp this flower, safety" (''[[Henry IV, part 1]]'', Act II Scene 3). The common figure of speech "to grasp the nettle" probably originated as a condensation of this quotation. It means to face up to or take on a problem that has been ignored or deferred. The [[metaphor]] refers to the fact that if a nettle leaf is grasped firmly rather than brushed against, it does not sting so readily, because the hairs are crushed down flat and do not penetrate the skin so easily. However the sting of nettles has been recommended to relieve the pain of rheumatism as the effects of the sting can last up to twelve hours. The stinging feeling becomes a warm feeling on the area treated so helping the pain of the rheumatism to subside.

==References==
<references/>

==External links==
*[http://www.pfaf.org/database/plants.php?Urtica+dioica Plants for a Future database entry for ''Urtica dioica''; comprehensive account with a long list of uses]
*[http://www.ars-grin.gov/cgi-bin/npgs/html/taxon.pl?40944 Germplasm Resources Information Network: ''Urtica dioica'']
*[http://www.efloras.org/florataxon.aspx?flora_id=2&taxon_id=220014002 Flora of China: ''Urtica dioica'']
*[http://mic-ro.com/plants/ Contact-poisonous plants of the world]
*Elliott, C. (1997). Rash Encounters. ''Horticulture'' 94: 30.
*Schofield, Janice J. (1998). ''Nettles'' ISBN 0-585-10500-6
*Thiselton-Dyer, T. F., (1889). ''[http://www.dominiopublico
.gov.br/download/texto/gu010118.pdf The Folk-Lore of Plants]''.
*Glawe, G. A. (2006). ''Sex ratio variation and sex determination in Urtica diocia.'' ISBN 90-6464-026-2

[[Category:Rosales]]
[[Category:Fiber plants]]
[[Category:Leaf vegetables]]
[[Category:Flora of Europe]]
[[Category:Flora of Estonia]]
[[Category:Flora of the United Kingdom]]

Stinging nettle - Revision history

Raffi at 13:15, 4 April 2007