Common nettle  (Urtica dioica)

Extremely common and widespread (3).

The common or stinging nettle is a well-known and highly successful 'weed' species (4). The roots are very tough and are yellow in colour, and the creeping stems, which often take root at their bases, produce shoots during spring (2). The oval-shaped leaves are easily recognised; they have deeply serrated edges and bear stinging hairs. These hollow hairs have a similar structure to hypodermic needles, and have a swollen base that contains the venom (4); an encounter with these leaves is not quickly forgotten (4). The specific part of the scientific name dioica means 'two houses', which refers to the fact that the male and female flowers are found on separate plants (4). The small whitish flowers are clustered in spikes known as inflorescences, which reach up to 10 cm in length (2).

Common and widely spread throughout Britain (2). Elsewhere it occurs in temperate parts of Europe and Asia (2), and has been introduced to many areas outside of this native range (3).

The common nettle prefers damp soils that are rich in nutrients. It occurs in a broad variety of habitats, such as woods, unmanaged grasslands, scrub, hedgerows, road verges, waste ground, gardens, farmland, fens and river banks (3).

The common nettle is a perennial species (3), which flowers from June to August (5) and spreads by seeds and by vegetative reproduction via creeping underground rhizomes (6). It is one of the most important plants in Britain for invertebrates, and is essential for many of our species of butterflies and moths, including the caterpillars of the beautiful small tortoiseshell (Aglais urticae) and peacock (Inacis io) butterflies (4). It is not grazed by animals due to the presence of the protective stinging hairs, and so the nettle provides a relatively safe habitat for insects and their larvae (4).

Humans have put the nettle to various uses; it does not sting when it has been cooked, and can be eaten like spinach or made into nutritious soups. A good green manure can be made by steeping the leaves in water, and in Germany the fibres were used to make army uniforms during the First World War when cotton was in short supply (6). It also has a number of medical uses, such as treatments for arthritis and gout (4).

This species is not threatened.

Conservation action is not required for this species.

For more on nettles see:
http://www.nettles.org.uk

For more information on British plants and their conservation see Plantlife- the wild plant conservation charity:
http://www.plantlife.org.uk/

Visit the website of the Botanical Society of the British Isles at:
http://www.bsbi.org.uk

• Inflorescences: the reproductive shoot of the plant, which bears flowers.
• Larvae: stage in an animal's lifecycle after it hatches from the egg. Larvae are typically very different in appearance to adults; they are able to feed and move around but usually are unable to reproduce.
• Perennial: plants that live for at least three seasons; after an initial period they produce flowers once a year.
• Rhizomes: rhizomes are thickened, branching, creeping storage stems. Although most rhizomes grow laterally just along or slightly below the soil's surface, some grow several inches deep. Roots grow from the underside of the rhizome, and during the growing season new growth sprouts from buds along the top. A familiar rhizome is the ginger used in cooking.
• Vegetative reproduction: type of asexual reproduction (reproduction without recombination of genetic material) that results in the propagation of plants using only the vegetative tissues such as leaves or stems. The resulting plant is genetically identical to the original plant. A well-known example of this is the reproduction of strawberry plants from 'runners'.

1. National Biodiversity Network Species Dictionary (February, 2003)
   http://www.nhm.ac.uk/nbn/
2. Clapham, A.R., Tutin, T.G. and Moore, D.M. (1987) Flora of the British Isles. 3rd Edition. Cambridge University Press, Cambridge.
3. Preston, C.D., Pearman, D.A. and Dines, T.D. (2002) The New Atlas of the British and Irish Flora. Oxford University Press, Oxford.
4. National be Nice to Nettles Week (February, 2003)
   http://www.nettles.org.uk
5. Press, B. and Gibbons, B. (1993) Photographic field guide to wild flowers of Britain and Europe. New Holland Publishers (UK) Ltd, London.
6. Mabey, R. (1996) Flora Britannica. Sinclair-Stevenson, London.