Butterbur  (Petasites hybridus)

Not threatened (3).

Butterbur is so called as the huge rhubarb-like leaves with their downy undersides were used to wrap around butter in the days before refrigerators (4). The leaves are still used today as impromptu sunshades or umbrellas; indeed the name of the genusPetasites derives from the Greek word petasos, a type of hat with a wide brim (5). The flowers of butterbur appear before the leaves, often as early in the year as February (4). The pink emerging flower stalks, pushing their way through the earth, are similar in appearance to button mushrooms, and in some parts of the country, butterbur plants were known as ‘early mushrooms’ (5). When fully extended, the stocky flower spikes are purplish towards the base, with pale reddish-violet flowers (2). Functional male and female flowers occur on separate plants; male flower spikes are shorter than those belonging to female plants (2).

This species has a wide distribution in Britain, although female plants are found only in north and central England (3). Colonies containing just male plants are thought to be clones from deliberately planted specimens, perhaps introduced to provide a supply of nectar for bee-keeping (3). Butterbur is found in mainland Europe as far north as Scandinavia. It also occurs in north and west Asia and has been introduced to North America (2).

Typically found growing in shady places beside waterways, in wet meadows and copses, marshes, flood plains and damp roadsides (2) (3).

Butterbur is a perennial herb, that spreads mainly by vegetative reproduction from fragments of an underground creeping structure called a rhizome(3). Individual plants function either as males or females, a condition known as ‘dioecy’. Bees visit the flower heads, although only sterile flowers produce nectar (2).

Butterbur has been highly valued as a medicinal plant since ancient times. Amongst other uses, the roots were dried and used to treat fevers, particularly the plague (5). More recently, research has shown that extracts of butterbur contain active ingredients that are extremely effective in preventing and reducing the pain associated with migraines and relieving the symptoms of asthma (6).

This species is not threatened at present.

Conservation action is not required for this common species.

For more on British native plants and for details of how to get involved in plant conservation visit the website of Plantlife, the wild plant charity:
www.plantlife.org.uk

• Dioecy: the condition where male and female flowers are borne on separate plants.
• Genus: a category used in taxonomy, which is below ‘family’ and above ‘species’. A genus tends to contain species that have characteristics in common. The genus forms the first part of a ‘binomial’ Latin species name; the second part is the specific name.
• Perennial: plants that live for at least three seasons; after an initial period they produce flowers once a year.
• Rhizome: 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 (September 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) New Atlas of the British and Irish Flora. Oxford University Press, Oxford.
4. Mabey, R. (1996) Flora Britannica. Sinclair-Stevenson, London.
5. Grigson, G. (1996) The Englishman’s Flora. Helicon Publishing, Ltd., Oxford.
6. English, J. (November 2002) Butterbur extract (Petasites hybridus) effective in reducing migraine attacks: http://www.worldwidehealthcenter.net/articles-99.html