Coastal Popcorn Lichen

Coastal popcorn lichen (Mobergia calculiformis) is a crustose lichen in the family Megasporaceae, found on exposed siliceous and calcareous rock surfaces in Mediterranean and Atlantic coastal habitats, including cliffs, sea walls, and rocky shores subject to salt spray. Its common name derives from the small, pale, granular or coralloid soredia that give colonies a popcorn-like appearance. The genus Mobergia is restricted to a small number of species adapted to harsh, sun-exposed maritime conditions. Like many lichen-forming fungi, Mobergia calculiformis exists in a mutualistic relationship with photosynthetic algae or cyanobacteria, forming a composite thallus able to tolerate desiccation, salt, and UV exposure. Coastal popcorn lichen is assessed as Endangered by the IUCN, reflecting its restricted habitat specificity and vulnerability to coastal development, air pollution, and invasive species that alter cliff-face communities. The species occurs sporadically along Atlantic European coastlines, including France, Spain, and Portugal, as well as Mediterranean outcrops. Its conservation depends on the preservation of undisturbed maritime cliff habitats.