Umbilicaria muhlenbergii is widely distributed in the eastern United States, and in central and eastern Canada. It grows on steep rock walls and on boulders. A study conducted on rock-dwelling lichens in a coastal barren of Nova Scotia revealed that Umbilicaria muhlenbergii was predominantly found on the back faces of boulders, and its abundance gradually increased as one moved away from the shoreline. This observation led to the inference that the presence of the ocean had a negative impact on its growth, although the lichen is likely to possess salt tolerance.
