Opegrapha is a genus of lichenized fungi, which means they form a symbiotic relationship with algae or cyanobacteria. These fungi are primarily found on the surfaces of rocks, bark, and other substrates in various environments. They are known for their unique fruiting bodies, called apothecia, which can vary in shape and color. This genus is part of the larger family Opegraphaceae and is characterized by its diverse species, each adapted to specific habitats. Opegrapha plays an essential role in ecosystems by contributing to nutrient cycling and serving as indicators of environmental health.