Two species of crustose (crustlike) lichens growing on a tombstone in a Norfolk (UK) churchyard. The bright orange rosettes with lobed edges are Calop

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Two species of crustose (crustlike) lichens growing on a tombstone in a Norfolk (UK) churchyard. The bright orange rosettes with lobed edges are Caloplaca sp, the grey clusters with upturned inner edges are Physcia adscendens. Symbiotic organisms, lichens consist of an algal & a fungal partner. The fungus benefits from the photosynthetic activity of the alga. The advantage to the alga remains unclear, but may lie in protection from drought & intense light. Slow growing organisms (1-2mm per year), they live to immense ages, colonising tree trunks, soil, rock, & mortar. Lichens are sensitive to sulphur dioxide & hence used to monitor air pollution.

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Size: 4228px × 4228px
Photo credit: © DR JEREMY BURGESS/SCIENCE PHOTO LIBRARY / Alamy / Afripics
License: Licensed
Model Released: No

Keywords: adscendens, air, algae, botany, caloplaca, dye, fungus, lichen, lichens, mutualism, nature, physcia, plant, pollution, sp, symbiosis, symbiotic