Spear thistle  (Cirsium vulgare)

Widespread and very common (3). Listed as a noxious weed under the Weeds Act of 1959 (4).

The spear thistle is perhaps the most likely candidate for the Scottish national emblem (5). It is a tall thistle, with a long tap-root(2). Young plants form rosettes of bristly leaves that have a downy upper surface; rosettes persist for around 1 year before flowering stems are produced (4). These flowering stems are cottony, deeply furrowed and have spiny 'wings', they support deeply lobed and spiny leaves (2). The large purple flower heads are 3-5 cm long and 2-5 cm across and are arranged in clusters (4).

Extremely widespread, being found throughout Britain. The listing of this species as a noxious weed subject to control does not seem to have affected its range; indeed it seems to be on the increase in man-made habitats (3). It occurs throughout the rest of Europe, reaching as far north as Scandinavia. It is also known in western Asia and North Africa, and has been introduced to North America and Chile (2).

This thistle thrives in a wide variety of habitats, such as rough grassland, overgrazed pasture, dunes, and sea-cliffs. It also occurs in fertile habitats subject to disturbance, including waste ground, arable fields, spoil heaps, and on burned areas of woodland (3). As it has been discovered in pre-Neolithic deposits, it seems that spear-thistle does not require human disturbance to prosper (1).

The spear thistle is a perennial species. Seedlings appear from autumn to April and they do not begin to flower until their second year of growth (4). Flowers are produced from July to September (6), and are pollinated by long-tongued bees, hover-flies and butterflies (2). After the seeds have been produced, the flowering stems die back (4).

This species is not threatened.

Not relevant.

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

• Neolithic: a cultural period of the Stone Age, which began around 10,000 B.C. The Neolithic is characterized by the making of polished stone tools and the development of agriculture.
• 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.

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. DEFRA. Spear thistle (Feb 2003): http://www.defra.gov.uk/environ/weedsact/spearths.pdf
5. Mabey, R. (1996) Flora Britannica. Sinclair-Stevenson, London.
6. Press, B. & Gibbons, B (1993) Photographic field guide to wild flowers of Britain and Europe. New Holland Publishers (UK) Ltd, London.