Bog asphodel  (Narthecium ossifragum)

Not threatened (3).

Bog asphodel produces bright yellow star-like flowers on leafless stems. On the damp heaths and peatbogs in which it is found, this is often the brightest show of colour around (4). The anthers are bright reddish-orange, and when the plants have finished flowering, the stems take on a deep saffron colour (5). The scientific name ossifragum means ‘bone breaker’ and refers to the old belief that after grazing on this plant the bones of sheep became brittle. This belief was mistaken, however, as bog asphodel was not the culprit; it was due to the calcium-deficient vegetation found in the habitats in which the plant grows (4). This plant has been used as a cheap substitute for saffron and as a dye. During the seventeenth century it was used as a hair dye by women in Lancashire (5).

Found throughout much of the British Isles, but is absent from many parts of eastern England and the Midlands (2). The species has undergone a decline in England, and local losses have continued in Sussex and Surrey (3). Bog asphodel can be found in north and western Europe, extending east to south-eastern Sweden and south to northern Portugal (2).

As the common name suggests, bog asphodel is found in wet, boggy habitats including wet heaths, moors and raised, valley and blanket bogs (3) (2). It is also found in wet acid habitats on mountains, up to altitudes of 1000m (2), and is unable to tolerate shade (2).

This perennial herb produces creeping rhizomes, from which it is able to spread by vegetative reproduction(2) (3). It can also reproduce by seeds, and the flowers are pollinated by a range of insects (2). Despite the fact that it is slightly toxic, bog asphodel is often heavily grazed in upland areas (3).

The range of this species has declined in Britain, largely as a result of the widespread drainage of wet habitats (4).

Conservation action has not been targeted at this 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

• Anther: part of the stamen (the male reproductive organ of a flower) that produces pollen. (See http://www.rbgkew.org.uk/ksheets/pdfs/flower.pdf for a fact sheet on flower structure)
• 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 (or propagation): 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 (January 2004): 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.