Spilonema

Spilonema is a genus of lichen-forming fungi in the family Coccocarpiaceae. These lichens form small, dark tufts of thread-like filaments that grow on rocks and are found in various regions from tropical to arctic climates. They partner with nitrogen-fixing cyanobacteria, which gives them their distinctive blue-green colouration and allows them to survive in nutrient-poor environments. The genus was established in 1856 by the French botanist Jean-Baptiste Édouard Bornet, who distinguished these species from similar-looking lichens based on their unique internal structure....read more on Wikipedia.