Francis' lichen  (Zamenhofia rosei)

Classified as Near Threatened in Great Britain (3).

Francis' lichen is a yellowish-green scattered crust, and the fruits are orange-brown but have never been recorded in Britain (4). The algal partner is Trentepohlia sp. (2). The Zamenhofia genus of lichens is named after the inventor of the Esperanto language, Ludwig Zamenhof (2).

Very rare in Britain, Francis' lichen occurs in the south of England, but is most frequent in the New Forest (2). Elsewhere the species occurs in France, Spain and Madeira (5).

Occurs on old trees, particularly oak (Quercus species) in ancient forests (5).

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; they have been used as 'indicators' of pollution (7) and are extremely slow-growing (8).

Whilst no immediate threats are apparent, it seems likely that this lichen is sensitive to the loss of old trees and unsuitable woodland management (9).

At present there is no conservation action being undertaken for this British Red Data Book Species.

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.
http://www.bio.bris.ac.uk/

• 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.
• 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.
• 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: relationship in which two organisms form a close association, the term is now usually used only for associations that benefit both organisms (a mutualism).

1. National Biodiversity Network Species Dictionary (September 2002) http://www.nhm.ac.uk/nbn/
2. Dobson, F. (2000) Lichens. An illustrated guide to the British specie. The Richmond Publishing Co. Ltd., Slough.
3. JNCC Plant Status Information (September 2002): http://www.jncc.gov.uk/species/pstatus/p4_1_3.htm
4. Serusiaux E (1991) Porina rosei, a new species in Western Europe. Cryptogamis Bryologie et Lichenologie12 (1): 31-40.
5. 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.
6. 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.
7. Duckworth, J. & James, P. W. Lichens as indicators of terrestrial eutrophication in the UK (September 2002): http://www.plantaeuropa.org/html/conference_2001/docs/Duckworth%20-%20LICHENS%20AS.doc
8. Hill, D. J (2002). Pers. comm.
9. Blaenau Gwent County Borough Council. (August 2002): http://www.blaenau-gwent.gov.uk/The%20Council/Departments/Environment_Development/env_implementation/Countryside/Biodiversity/Species%20pdfs/plants&funghi2002.pdf