Common dandelion  (Taraxacum officinale agg)

Common dandelion in flower

Facts

Kingdom Plantae
Phylum Anthophyta
Class Magnoliopsida
Order Asterales
Family Asteraceae
Genus Taraxacum (1)
Size Flower head diameter: 2.5 - 7.5 cm (2)

Status

Extremely common and widespread (3).

Description

Dandelions are well-known, robust weeds; the common name derives from the French 'dent de lion', meaning 'lion's tooth', which refers to the deeply toothed, deep green leaves (4), which are arranged in rosettes (5). The bright yellow flower heads are borne on hollow stalks (5), and the downy seed heads are familiar to children as dandelion clocks, which are used to 'tell the time' by the number of blows taken to remove the seeds (4). Vernacular names for the dandelion include 'wet-the-bed' and 'pissy-beds', which refer to the belief that just touching part of a dandelion can cause bed-wetting (4).

As most British dandelions produce fruit without being fertilised (they are 'apomictic'), substantial problems arise with the taxonomy of these plants. This group is a 'complex' consisting of around 200 microspecies, and is typically treated as a species aggregate, denoted as 'Taraxacum officinale agg.' (1).

Range

Dandelions are common and widespread throughout Britain (3). The Taraxacum aggregate has a wide, circumpolar distribution (2).

Habitat

Found in a very wide variety of habitats, but tend to thrive best in disturbed sites such as lawns, paths, waste ground, pastures and road verges. Some microspecies are found in natural or semi-natural habitats, including fens, sand dunes and chalk grassland (3).

Biology

Dandelions have deep taproots, and the whole plant contains a milky fluid known as latex (6). It is perennial, and flowers throughout the year (5). The flowers close at night, and can produce around 2,000 wind-dispersed fruits (1). Plants can also regenerate from pieces of the tap root (1).

Although generally regarded as a weed, dandelions have many uses, both culinary and medicinal (6). It is a scientifically proven diuretic and laxative (4), and has also been used as a tonic, to treat rheumatic problems, and as a blood purifier (6). Young leaves and flowers are used in salads, stir-fries and other recipes, and the root can be dried to make a substitute for coffee, a practice that was common during the rationing of the Second World War (4).

Threats

This species is not threatened.

Conservation

Not relevant.

Further Information

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

Authentication

This information is awaiting authentication by a species expert, and will be updated as soon as possible. If you are able to help please contact
arkive@wildscreen.org.uk

Perennial: plants that live for at least three seasons; after an initial period they produce flowers once a year.
Tap root: a large central root.

References

  1. National Biodiversity Network Species Dictionary (Feb 2003):
    http://www.nhm.ac.uk/nbn
  2. Clapham, A.R., Tutin, T.G. & Moore, D.M. (1987) Flora of the British Isles. 3rd Edition. Cambridge University Press, Cambridge.
  3. Preston, C.D., Pearman, D.A. & Dines, T.D. (2002) The New Atlas of the British and Irish Flora. Oxford University Press, Oxford.
  4. Mabey, R. (1996) Flora Britannica. Sinclair-Stevenson, London.
  5. Press, B. & Gibbons, B (1993) Photographic field guide to wild flowers of Britain and Europe. New Holland Publishers (UK) Ltd, London.
  6. New Zealand Institute for Crop and Food Research Ltd. Taraxacum officinale. (Feb 2003):
    http://www.crop.cri.nz/psp/broadshe/PDF/058dandelionA4.pdf