flame lichen
sur-falise lichen
Lichens occur in some of the most extreme environments on
Earth—arctic tundra, hot deserts, rocky coasts, and toxic slag heaps.
However, they are also abundant as epiphytes on leaves and branches
in rain forests and temperate woodland, on bare rock, including walls and gravestones, and on exposed soil surfaces (e.g., Collema) in otherwise mesic habitats.
crustose lichens
Lichens are widespread and may be long-lived; however, many are
also vulnerable to environmental disturbance, and may be useful to scientists in assessing the effects of air pollution, ozone depletion,
and metal contamination. Lichens have also been used in making
dyes and perfumes, as well as in traditional medicines.