Peltula lobata

Peltula lobata is a species of foliose and saxicolous (rock-dwelling) lichen in the family Peltulaceae. Formally described in 2013, this lichen typically colonises vertical, sun-exposed rock crevices along riverbanks and periodically submerged surfaces in temporary riverbeds. The species grows primarily on schist, quartzite, and granite substrates, and forms large, conspicuous brown patches at relatively low elevations. Originally documented in northeastern Portugal, it has also been recorded at two sites in Spain. P. lobata grows in Mediterranean environments characterised by sub-humid to semi-arid conditions, where it often serves as the sole coloniser of thin cracks or river-washed crevices before giving way to other species as these habitats develop....read more on Wikipedia.