Lecanora Muralis

Day 15: This specimen would have left me puzzled, but its identity (Lecanora muralis) was provided by Katherine Glew during a "lichen walk" in one of Seattle's cemeteries yesterday. According to some sources (particularly those in the UK), it is most often found in urban environments where deposits of grit and ash on various substrates provide it with an easy means to take hold. It is unusual among Lecanoras in that it is lobate, i.e., the outer edges of the rosette are scalloped by small, loosely attached lobes much like those of the Parmelias. However, the apothecia (disk-like fruiting bodies) give it away as a Lecanora. This specimen was roughly 1.25" across and at least for me, it was one of the most interesting finds of the day.