Buellia erubescens

Buellia erubescens, the common button lichen, is a species of lichen in the genus Buellia. It is found commonly on the bark and occasionally on the wood of Quercus, Pinus, Juniperus, or other species of trees with bark that has generally low pH. It is common between 600 and 3000 m elevation, and is common in submontane to subalpine forests.

Distribution
Buellia erubescens is widely distributed throughout the North America and Europe.