How to Be a Lichen: Adaptive Strategies for the Vulnerabilities of Being Human from Nature’s Tiny Titans of Tenacity

When I was a child, little delighted me more than the magical green garlands draping from the pine trees, which I made into wreaths and mustaches to roam the mountains of Bulgaria as a miniature Orlando. I had no idea that Usnea longissima is just one of more than 20,000 known species of lichen — almost twice as many as birds.

In the lifetime since, I have collected and photographed lichen all over the world, from the spruces lining the wild shores of Alaska to the stone walls lining the rural r...