Lichen attach to rocks via a central holdfast (umbilicus).

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References

"The umbilicus is of vital importance for the Umbilicaria species, since it fastens the thallus to the rock." (Gauslaa 1984:20)

Journal article
Infrared and visible reflectance in different lichen species and its ecological significanceGauslaa, Y.

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Living System/s

Organism
Navel LichenUmbilicariaSpecies

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