Lichens are stable, self-supporting associations between a fungus and an alga or cyanobacterium.
Keywords: algae; cyanobacteria; fungi; pollution; symbiosis
Lichens
David L Hawksworth, MycoNova, London, UK
Published online: January 2002
DOI: 10.1038/npg.els.0000368
|
Figure 1. A mixed assemblage of lichens on the ground in a lowland heath, including Cladonia coccifera (with scarlet apothecia), C. portentosa (erect grey branched thalli), and Pycnothelia papillaria (grey crustose thallus with erect papillae). Magnification × 2. Copyright © with permission of DL Hawksworth.
|
|
Figure 2. Vertical section through the thallus of a foliose lichen, Parmelia sulcata, showing (top to bottom) the upper cortex of compact fungal tissue, the algal layer (with Trebouxia cells stained dark blue) medulla of loosely interwoven hyphae, and the lower cortex of compacted dark brown fungal tissue. Magnification × 400. Copyright © with permission of DL Hawksworth.
|
|
Figure 3. The lichen-forming fungus Sticta filix. The fungus associates with cyanobacteria (Nostoc) to form shrubby blue-grey thalli, and with green algae (Trebouxia) to produce fawn leafy thalli. Magnification × 10. Copyright © with permission of DL Hawksworth.
|
| References | |
| Edwards HGM and Seaward MRD (1993) Raman microscopy of lichen–substratum interfaces. Journal of the Hattori Botanical Laboratory 74: 303–316. | |
| Esseen P-A, Ericson L, Lindström H and Zackrisson (1981) Occurrence and ecology of Usnea longissima in central Sweden. Lichenologist 13: 177–190. | |
| Gargas A, DePriest P, Grube M and Tehler A (1995) Multiple origins of lichen symbioses by SSU rDNA phylogeny. Science 268: 1492–1495. | |
| Hawksworth DL and Rose F (1970) Qualitative scale for estimating sulphur dioxide air pollution in England and Wales using epiphytic lichens. Nature 227: 145–148. | |
| Hawksworth DL and McManus PM (1989) Lichen recolonization in London under conditions of rapidly falling sulphur dioxide levels, and the concept of zone skipping. Botanical Journal of the Linnean Society 100: 99–109. | |
| book Hawksworth DL, Kirk PM, Sutton BC and Pegler DN (1995) Ainsworth & Bisby's Dictionary of the Fungi, 8th edn. Wallingford: CAB International. | |
| book Honegger R (1992) "Lichens: mycobiont–photobiont relationships". In: Reisser W (ed.) Algae and Symbioses: Plants, Animals, Fungi, Viruses Interactions Explored, pp. 255–275. Bristol: Biopress. | |
| Innes J (1985) Lichenometry. Progress in Physical Geography 9: 187–295. | |
| Lawrey JD (1993) Lichens as monitors of pollutant elements at permanent sites in Maryland and Virginia. Bryologist 96: 339–341. | |
| book Nash TH III and Wirth V (eds) (1988) Lichens, Bryophytes and Air Quality. Berlin: J Cramer. | |
| Further Reading | |
| book Ahmadjian V (1993) The Lichen Symbiosis, revised edn. New York: Wiley. | |
| book Bates JW and Farmer AM (eds) (1992) Bryophytes and Lichens in a Changing Environment. Oxford: Clarendon Press. | |
| book Galun M (ed.) (1988) Handbook of Lichenology (3 vols). Boca Raton, FL: CRC Press. | |
| Hawksworth DL (1988) The variety of fungal-algal symbioses, their evolutionary significance, and the nature of lichens. Botanical Journal of the Linnean Society 96: 3–20. | |
| Hawksworth DL (1994) The recent evolution of lichenology: a science for our times. Cryptogamic Botany 4: 117–129. | |
| book Kershaw KA (1985) Physiological Ecology of Lichens. Cambridge: Cambridge University Press. | |
| book Lawrey JD (1984) Biology of Lichenized Fungi. New York: Praeger. | |
| book Nash TH III (ed.) (1996) Lichen Biology. Cambridge: Cambridge University Press. | |
| book Richardson DHS (1992) Pollution Monitoring with Lichens. Slough: Richmond Publishing. | |
| book Seaward MRD (ed.) (1977) Lichen Ecology. London: Academic Press. | |
