Save Word. Definition of nettle Entry 1 of 2. Definition of nettle Entry 2 of 2. Illustration of nettle Noun nettle 1 In the meaning defined above. Synonyms Choose the Right Synonym Did you know? Synonyms for nettle Synonyms: Verb aggravate , annoy , bother , bug , burn up , chafe , eat , exasperate , frost , gall , get , grate , gripe , hack off , irk , irritate , itch , nark [ British ], peeve , persecute , pique , put out , rasp , rile , ruffle , spite , vex Visit the Thesaurus for More.
Choose the Right Synonym for nettle Verb irritate , exasperate , nettle , provoke , rile , peeve mean to excite a feeling of anger or annoyance. Did you know? Verb If you've ever brushed against nettles, you know those weeds have sharp bristles that can leave you smarting and itching. Examples of nettle in a Sentence Verb The mayor's recent actions have nettled some members of the community.
It nettles him that his younger coworker got a promotion before he did. Recent Examples on the Web: Noun The remaining balance is 64 percent organic cotton and 18 percent cotton- nettle blend. Sanders nettled some Jews by making a campaign appearance on Rosh Hashana, a day most Jews take off from work, at Liberty University, an evangelical college in Virginia founded by the Rev.
Jerry Falwell. First Known Use of nettle Noun before the 12th century, in the meaning defined at sense 1 Verb 15th century, in the meaning defined at sense 1. Learn More About nettle. Time Traveler for nettle The first known use of nettle was before the 12th century See more words from the same century. Each hair is really a miniature hypodermic needle ready to spring into action.
At the tip is a lopsided bulb-like structure that is easily broken at a pre-stressed region. With the slightest touch, the tip falls off leaving the sharp point which can easily penetrate skin. At the base of the hair is a reservoir of irritant, believed to be chemically similar to that injected in ant stings, which is under pressure and escapes through the tip into the victim.
The result is a minor dermatitis which will go away in most individuals after thirty minutes or so. This dermatitis, known as urticaria, gives the genus its Latin name, Urtica. However, in monoecious plants with both male and female flowers, the proportion of male flowers increased when plants were grown under more favourable conditions. In fact, nearly half of the plants that initially appeared monoecious exclusively produced male flowers when grown in more fertile soils.
She suggested, as a result of her crossing experiments, that males represent the heterogametic sex and females the homogametic sex. However, sex determination does not follow a clear-cut scheme and it seems that genes on different loci are involved in sex determination. Shannon and Holsinger also reported a complicated picture of sex determination in U. Most significant was evidence for a maternal influence on sex determination and for the possibility of gynodioecy as an intermediate stage in the evolutionary pathway to dioecy.
The North American subspecies gracilis is mostly monoecious, with staminate and pistillate flowers on each shoot Bassett et al. However some panicles are entirely male, some entirely female and some are mixed, with hermaphrodite flowers occasionally being produced.
Male flowers appear mostly in June and July and female flowers later in the growing season. Although the plants are self-compatible, this difference in flower time of males and females must to some extent lead to more crossing than selfing. Nettle plants produce abundant seed. Those growing in full sunlight produce 10,, seeds per shoot Bassett et al. The average seed weight is 0. Besides producing seeds, plants spread vegetatively by means of rhizomes or stolons.
A rhizome planted in late summer can spread into a 2. Pollard and Briggs b explored the structure and function of the stinging hairs of U. When brushing contact is made with a hair the swollen tip is broken off obliquely along a more or less predetermined fracture line, leaving a sharp point "resembling the beveled tip of a hypodermic needle". This point penetrates the skin and the subsequent pressure squeezes the base of the stinging cell which thus actively injects the toxin contained within it.
Pollard and Briggs b point out that despite a great deal of biochemical and pharmacological research over the past years, the precise nature of the toxin is not fully understood, although it is known to contain serotonin and acetylcholine Connor, Flowering in Britain takes place from late May to early August and viable seed is shed or may remain on the dead stems until December or January. The seeds of North American plants of U. With regard to plant development, new rhizomes are produced in late summer or autumn either from old rhizome material or from the base of aerial shoots Greig-Smith, They continue to grow at or just beneath the soil surface until the death of the aerial shoots when they turn upwards to form new shoots.
Young rhizomes are reddish in colour and have stinging hairs and scale leaves. Older rhizomes and roots have a yellow corky layer and so appear yellow in colour. The roots branch profusely and form many fine laterals. Greig-Smith says that new aerial shoots of U. Flowering begins in late May or June.
In Canada, according to Bassett et al. Taylor cites work by Grime and Hunt in saying that although U. Wheeler , cited in Taylor , compared the growth of woodland and pasture clones of U. Plants shaded by deciduous woodland grew better in their light regime of The same author says that the plant cannot withstand flooding of its rhizomes and roots for long periods. Greig-Smith observed that the shoot tips are not affected by spring frosts but may die back after early autumn frosts.
According to Bayer CropScience , stands of U. Taylor quotes Thompson and Grime in saying the seed bank of U. Wheeler , cited by Taylor, found a seed bank which varied between to viable seeds m -2 in floodplain pasture. Roberts and Bodrell sowed seeds of U. The soil was periodically cultivated, and seedlings continued to emerge for 5 years, with peak seasonal emergence in April, and the greatest number emerging in the first year.
These patches are often the product of a single individual that has spread by rhizomes which can be 50 cm or more in length Greig-Smith, Greig-Smith reported the British occurrence of U.
The same author, along with many others, commented on its apparent preference for soils with a high nitrate content. However, Bates suggested that the controlling factor was the soft, unconsolidated nature of favoured substrates rather than high nitrate. Ivins found that U. Taylor describes a number of experimental studies on the interactions of nitrogen and phosphate and their effects on the growth of nettle plants. Unless phosphate is added, in some soils seedlings grow extremely slowly and exhibit the characteristic symptoms of severe phosphate deficiency.
Hence, the distribution of nettles seems to be limited by phosphate availability Taylor, Piggot found that in well-lit sites U. In Denmark, Olsen observed that plant species growing along with U. Greig-Smith listed associated species in several habitats in Britain, including fen carr, different woodlands and scrub, boulder beaches and river banks.
Taylor , again in Britain, lists associated species in swamps and tall-herb fens, woodlands, scrub and hedges, mire vegetation, mesotrophic and calcicolous grasslands, in maritime vegetation and among crops in arable agriculture. Plant species commonly associated with U. One of the few species capable of persisting in almost monospecific stands of U. Rorison found that for U. Taylor interpreted the results of Piggot and Jankowska-Blaszcuk and Daws on the effects of light quality and quantity on germination as meaning that seeds are only likely to germinate in micro-sites near the soil surface and in the absence of overtopping vegetation.
Jankowska-Blaszcuk and Daws demonstrated that small seeds like those of U. According to Bayer CropScience , U. Their rhizomes have difficulty penetrating compacted soil, so open-textured soils of pH 5.
Slugs and snails find the leaves of nettles very palatable even though their resulting faeces may be packed with stinging hairs Grime et al. In Britain and elsewhere the larvae of small tortoiseshell Aglais urticae and red admiral Vanessa atalanta butterflies are commonly or exclusively found on stinging nettles Davis, , Taylor presents an even longer list of phytophagous insects found on U.
In south Wales, larvae of Eupteryx cyclops and E. Bassett presents a long list of insects, microorganisms and viruses associated with U. In New Zealand, the endemic New Zealand red admiral butterfly Bassaris gonerilla is restricted to species of Urtica, but has been in decline since Monarch Butterfly New Zealand Trust, , probably in part due to a reduction in populations of the endemic New Zealand tree nettle U.
Both B. According to Taylor , fallow deer Dama dama , roe deer Capreolus capreolus and red deer Cervus elaphus consume U. Cuscuta europaea , the European dodder, is an annual rootless stem holoparasite that obtains resources for its own growth and reproduction from the host plant through haustorial connections that penetrate into the host vascular tissue. Plants originating from parasitized populations flower later and allocate less biomass to asexual reproduction stolon production compared to plants from unparasitized populations, indicating possible selection by the parasite for late flowering and against asexual reproduction in U.
Taylor suggests that the perianth assists in wind dispersal of U. Seeds can also be dispersed by water as they can survive floating in water for a week Bond et al, According to Taylor , seed dispersal in U. Farm animals are known to eat nettles after they have been cut and dried so seeds can also be ingested by browsing cattle, as well as by deer and birds, pass through the digestive system and be excreted Greig-Smith, Seeds are also ingested by earthworms, to be later excreted in wormcasts McRill, Seed of U.
Further deliberate introduction to countries where U. Seed is available to buy on the Internet. Where it occurs in pastures and grasslands its monospecific clumps can take up considerable space and thus reduce hay yields and the amount of grass available to livestock. It is normally avoided by livestock, thus restricting their free movement.
Although considered native to Canada, it is listed as a noxious weed in several provinces Carey, , including Nova Scotia and Quebec Darbyshire, and Alberta and Manitoba Bassett et al. In the USA, U. According to Bayer CropScience , it is a weed of cereal and other field crops, is difficult to eradicate and is an important alternative host of the economically damaging carrot fly Psila rosae.
The weediness of U. Where U. Generations of children and adults have suffered the stinging hairs of U. A number of toxins are present in the stinging hairs, including serotonin and acetylcholine Connor, A report in Anon. Symptoms included trembling, pain, slobbering, dyspnoea and vomiting. Without treatment some dogs died days after exposure. The action of the stinging hairs is neutralized by heat or by drying, so leaves can be used for edible purposes quite safely PFAF, The copious wind-blown pollen of U.
Bast fibres from U. In Europe, it was cultivated commercially during the 19th and 20th centuries, right up until the Second World War. Many traditional clones were developed, with fibre contents ranging from 1. Harvesting starts in the second year of growth and the crop may produce well for several years. Nettle plants are commonly used by organic gardeners to produce a liquid plant feed Royal Botanic Gardens Kew, Until recently nettles were cultivated in Scotland, Denmark and Norway for use in the food, textile and medicinal industries.
According to Bown , plants are harvested commercially for the extraction of chlorophyll for use as a colouring agent and in foods and medicines. Dried nettle leaves and extracts are available from many herbal outlets. Seeds of U. People in many parts of the world still use freshly collected young leaves and stems of U.
The tender young leaves and shoots are used fresh, for example in soup, which is reputed to clean the blood, or as a vegetable. The mature leaves are used in the production of cheese notably Cornish Yarg and in pesto, cordials and herbal tea.
In modern Turkey, although nettle tea is a popular commercial herbal tea, its ingestion is not without risks. Sahin et al. Uslu et al. Traditionally U. It is also claimed to have antiasthmatic, antidandruff, astringent, depurative, diuretic, galactogogic, haemostatic and hypoglycaemic properties PFAF, A traditional remedy for rheumatism involves stinging the affected area with fresh nettle leaves, an effect apparently due to the anti-inflammatory properties of the stinging hair toxins Royal Botanic Gardens Kew, Nencu et al.
Further information on the medicinal and other uses to which U. Nettles sustain a rich and diverse invertebrate fauna, with around insect species benefitting from the plant Davis, They are a food source for many butterfly and moth larvae, and ladybirds consume the aphids that thrive on the plants.
The numerous seeds produced are an important food source for birds Royal Botanic Gardens Kew, Uncertainty reigns over the nomenclature of Urtica species, and many taxa within the genus are easily confused with others. Some of the species and subspecies also form hybrids, further adding to the confusion. McAllister suggested that U. Due to the variable regulations around de registration of pesticides, your national list of registered pesticides or relevant authority should be consulted to determine which products are legally allowed for use in your country when considering chemical control.
Pesticides should always be used in a lawful manner, consistent with the product's label. To prevent nettle infestations of grasslands, Natural England recommend avoiding the creation of bare ground and avoiding nutrient enrichment. According to Bayer CropScience , eradicating an established stinging nettle colony is difficult because the extensive root system expands annually and cannot be suppressed by mowing, although cutting when the new shoots reach a height of cm tall was recommended as a means of eradication by the UK Ministry of Agriculture and Fisheries in Non-chemical control measures for U.
Bayer CropScience claims that some control of nettles may be obtained through repeated tillage and cultivation over several years.
Carey reported that U. Greig-Smith reported that the species will not withstand repeated cutting. Machines for pulling out grassland weeds have been developed and are seen as environmentally friendly alternatives to herbicide use. One such, developed in the late s, is the Eco-Puller, a tractor-trailed and PTO-driven machine that pulls weeds from the ground in a way that mimics hand pulling. This is achieved by feeding tall plants between a pair of gripping rollers which then provide a good firm vertical pull which is necessary to get the root out of the ground.
The weed gripping height is adjustable, but weeds should be at least 30 cm tall to be pulled effectively. Stinging nettle should be pulled early in the season as soon as the stems are robust Natural England, No biological control agents have been identified for this species and, since it is considered native to several continents, a search for such agents would probably not be practical.
However, Popay et al. In their evaluation of cutting as a control measure for U. However, cutting every 5 weeks together with reseeding with the strongly competitive species Dactylis glomerata and Trifolium repens gave the best control. Although U. However, although livestock usually avoid mature plants, they will often eat them as seedlings or when cut and wilted Natural England, Pollard and Briggs b reviewed literature on the subject and found that some breeds of cattle, rabbits and American bison Bison bison consumed nettles at least on some occasions.
Taylor notes fallow deer Dama dama , roe deer Capreolus capreolus and red deer Cervus elaphus as feeding on nettles. When Pollard and Briggs b tested U. Both grazing species sometimes showed signs of immediate pain response. In further experiments in an area populated by wild rabbits, the more or less stingless nettle plants were much more heavily grazed than those with more dense stinging hairs.
The taxonomy of Urtica dioica clearly needs further scrutiny and, since the diploid and tetraploid North American subspecies do not normally interbreed Basset et al. Anon, Stinging nettle Urtica sp. Veterinary and Human Toxicology, 24 4 The family Urticaceae in Canada. Canadian Journal of Botany, 52 3 The biology of Canadian weeds. Urtica dioica L.
Canadian Journal of Plant Science, 57 2 Bates GH, The distribution and control of the great stinging nettle. Journal of the Ministry of Agriculture, Bayer CropScience, Urtica dioica. The biology and non-chemical control of common nettle Urtica dioica L. Bown D, London, UK: Dorling Kindersley. Cadbury CJ, Botanical implications of bracken control. Botanical Journal of the Linnean Society, 73 Carey JH, Countryside Survey: UK results from
0コメント