Okay, so it doesn’t look like the most exciting thing we could ever hope to find in the forest, but without it, those fallen oak trees would have a pretty difficult time recycling back into the earth.

This is Xylobolus frustulatus, or ceramic parchment — a crust fungus that degrades lignin, hemicellulose, and cellulose in oak trees. While it performs most of its work on the microscopic level, its presence can be detected by these tile-like “frustules” that cover logs, sticks, and stumps.

It’s fairly common and available for appreciation year-round, so if you find yourself walking through the woods, take a look around and say hello to your friendly crust fungus, Xylobolus frustulatus.

Photograph taken December 2015 at Hartwood Acres, Western Pennsylvania