Peltigera membranacea - Dog lichen

Found in Vitosha mountain near Soifa, at about 1200 m.a.s.l., on a moss covered rock in a beech forest. P. membranacea is among the fewer than 10% of lichens that contains cyanobacteria rather than algae; it contains Nostoc, the most common cyanobacterial genus occurring in lichens.