I am running a two hours "Lichens for Beginners Walk" at Linton Church on Saturday 5 April 2025 starting at 9.15am. - please book by emailing zoom-improvement@britishlichensociety.org.uk Details here
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I associate the fluorescent yellow green of this crustose lichen with slates of the Lake District and North Wales. It is said to be a lichen which which grows on rocks in mountainous areas of low air pollution However it does grow on acid rocks in this part of Yorkshire too, and its colour makes it stand out.
There is a patch on this buttress near the church porch.
Rhizocarpon has been put outside a space station in outer space, suffering no atmosphere and intense radiation - and on return to earth was able to continue growing. This is an example of an extremophile
The green parts of the thallus (like little islands - called areoles- contain the mixture of algae and fungi. The black lines between them, and thick at the edge are just fungus - called prothallus.
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| This is a picture of the thallus (lichen body) enlarged . I showed this to the Lichen Chat and Improvement Group and they said that the black splodges are a fungal infection. |
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| Judith at Helwith Bridge/Foredale pointing to the Rhizocarpon geographicum on the Ordovician / Silurian rocks near the Quarry |
