Scrambled-egg lichen (Fulgensia fulgens)
|Size||Fruiting body diameter: 0.5 - 1.5 mm (7)|
Thallus diameter: up to 3 cm (7)
Classified as Near Threatened in Great Britain (3).
As the common name suggests, scrambled-egg lichen has a thin, crust-like egg-yellow thallus (body), which consists of smaller rosettes and paler blotches (2). The generic part of the scientific name 'Fulgensia' is derived from the Latin word for shining, and refers to the bright yellow colour of the thallus (2).
Occurs in the south and east of England, in Breckland (East Anglia), Somerset, the Channel Islands and the Isle of Wight, but it is rare (4). It also occurs in southwest Wales (5), but has been lost from Sussex (4). It is widespread in warm parts of the Northern Hemisphere especially the Mediterranean, as well as Australia and New Zealand (4).
Occurs on the ground on moss and soil on well-lit free-draining (4)calcareous soils or dunes (2), in warm, open and often south-facing sites near sea level (4).
Lichens are remarkable organisms; they are stable combinations of an alga and/ or a cyanobacteria with a fungus, living together in a symbiotic association (2). The fungus causes the alga to release sugars, which allow the fungus to grow, reproduce and generally survive. The fungus provides protection for the alga, and enables it to live in environments in which it could not survive without the fungal partner (2). A general rule is that the fungal component of a lichen is unable to live independently, but the alga may live without the fungus as a distinct species (6). Many lichens are known to be very sensitive to environmental pollution, and they have been used as 'indicators' of pollution (5).
Eutrophication caused by the run-off of fertilisers from fields is thought to have caused the dramatic decline of scrambled-egg lichen at Stackpole National Nature Reserve in southwest Wales. A decline in rabbit grazing and the resultant growth of rank vegetation is also thought to have caused some losses (5). Furthermore, excessive trampling by animals and humans or other soil disturbance will destroy thalli and prevent this slow-growing species from re-establishing and developing again (8).
This species has been monitored at Stackpole National Nature Reserve, where it also receives a level of protection as a result of the site designation (5).
For more on British lichens see: Dobson, F. (2000) Lichens. An illustrated guide to the British species. The Richmond Publishing Co. Ltd., Slough.
For more on threatened lichens see: Church, J.M., Coppins, B.J., Gilbert, O.L., James, P.W. & Stewart, N.F. (1996) Red Data Book of Britain and Ireland: lichens. Volume 1: Britain. The Joint Nature Conservation Committee, Peterborough.
Information authenticated by Dr D. J. Hill of the University of Bristol.
- Alga: a collection of taxonomically unrelated groups that share some common features but are grouped together for historical reasons and for convenience. They are of simple construction, and are mainly photoautotrophic, obtaining all their energy from light and carbon dioxide, and possess the photosynthetic pigment, chlorophyll A. They range in complexity from microscopic single cells to very complex plant-like forms, such as kelps. Algal groups include blue-green algae (cyanobacteria), red algae (rhodophyta), green algae (chlorophyta), brown algae and diatoms (chromista) as well as euglenophyta.
- Calcareous: containing free calcium carbonate, chalky.
- Cyanobacteria: a group of bacteria that are able to photosynthesise and contain the pigment chlorophyll. They used to be known as ‘blue-green algae’. They are thought to have been the first organisms to produce oxygen; fossil cyanobacteria have been found in 3000 million year old rocks. As they are responsible for the oxygen in the atmosphere they have played an essential role in influencing the course of evolution on this planet.
- Eutrophication: nutrient enrichment of aquatic or terrestrial ecosystems.
- Fungus: fungi are one of the taxonomic kingdoms, separate from plants and animals. They obtain nutrients by absorbing organic compounds from the surrounding environment.
- Symbiotic: relationship in which two organisms form a close association, the term is now usually used only for associations that benefit both organisms (a mutualism).
- Thallus: type of simple plant body that does not have stems, leaves and roots.
National Biodiversity Network Species Dictionary (September 2002)
- Gilbert, OL (2000) Lichens. HarperCollins, London (No 86 New Naturalist Series).
JNCC Plant Status Information (September 2002):
- Dobson, F. (2000) Lichens. An illustrated guide to the British species. The Richmond Publishing Co. Ltd., Slough.
- Purvis, O. W., Coppins, B. J., James, P. W. & Moore, D. M. (1992) The lichen flora of Great Britain and Ireland. Natural History Museum Publications. The British Lichen society, London.
Duckworth, J. & James, P. W. Lichens as indicators of terrestrial eutrophication in the UK (September 2002):
- Church, J.M., Coppins, B.J., Gilbert, O.L., James, P.W. & Stewart, N.F. (1996) Red Data Book of Britain and Ireland: lichens. Volume 1: Britain. The Joint Nature Conservation Committee, Peterborough.
- Hill, D. J. (2002) Pers. comm.