Bogbean (Menyanthes trifoliata)

Also known as: bog hop, buckbean
GenusMenyanthes (1)
SizeLeaf length: 3.5 – 7 cm (2)
Flower diameter: 15 mm (2)
Height of flower stalk: 12 – 30 cm (2)

Common and widespread. Not threatened (3).

Bogbean is an aquatic or bog plant, hence the common name (2). The ‘bean’ part of the name refers to the smooth-edged shiny leaves, which are roughly similar in appearance to those of young broad beans (4). Each leaf is divided into three leaflets, hence the specific part of the Latin name, trifoliata, meaning ‘three leaves’. The leaves and flowers are typically raised above the surface of the water, arising from creeping root-like storage organs known as ‘rhizomes’ (2). The smooth flower stalk can grow to 30 cm. It bears numerous white delicate, feathery, and star-like flowers which have a pinkish flush on the outside of the petals (2). The alternative common name ‘bog hop’ arose from the use of the leaves as a flavouring in beer-making (5).

This native plant is fairly common throughout Britain, reaching altitude of 915 meters (2). It has decreased in range in parts of the south east of England, mainly as a result of the large-scale drainage of wetlands that has occurred (3). Bogbean is found throughout most of Europe but becomes rare in the Mediterranean area. It also occurs in north and central Asia, Morocco, Greenland and North America (2).

Grows at the shallow margins of lakes, slow-flowing rivers, ponds, bogs and dune slacks. It cannot live in shade (3).

Bogbean is a perennial plant, that flowers from May to July (6). The flowers are pollinated by various insects (2).

Both the leaves and the root have a bitter taste, and were once used to treat jaundice and rheumatism. The leaves were used to flavour beer instead of hops in northern England and parts of Europe (5).

This species is not threatened at present, however drainage of wetlands has caused a marked decrease in this species in south-east England (3).

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:

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:

  1. National Biodiversity Network Species Dictionary (September 2003):
  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. (December 2003):