ⓘ Pleopsidium chlorophanum

                                     

ⓘ Pleopsidium chlorophanum

Pleopsidium chlorophanum is a distinctively colored, bright lemon-yellow to chartreuse crustose lichen, which favors dry arctic or alpine sandstone cliffs and boulders. Its a rare alpine lichen in Europe. It is in the Pleopsidium genus of the Acarosporaceae family.

This lichen is one of the few species able to survive at high altitudes in Antarctica, at altitudes up to 2000 meters. He is able to cope with high UV, low temperature and dryness. In the Antarctic habitat, it can be found on the surface, but it mostly in the crevices, where only a small amount of ambient light reaching it. This is probably adaptive behavior to protect it from UV radiation and desiccation. Remains metabolically active at temperatures down to -20 C, and can absorb small amounts of liquid water in ice and snow.

This is of particular interest to astrobiology, because it is one of the most Mars like environments on Earth. In 34 days of the experiment, when placed in a Mars simulation chamber, it continues to photosynthesize, and it is adapted to the conditions of Mars and even adapted physiologically by increasing its photosynthetic activity, and produce new growth.

It is similar to Acarospora schleicheri, growing on soil lichen, and rarely on rock, and yellow Pleopsidium. that grows in high altitudes of Alpine on vertical or overhanging hard acidic rocks, e.g. granite in Western North America.

Its thallus grows in a circular outwardly radiating pattern crustose placoidioid, with a 1mm wide blade edge. It differs from yellow Pleopsidium in having a smooth, small squamulose thallus and larger apothecia are located spore-forming structures