Covering almost 8 percent of the earth's terrain, lichens are living beings which are familiar to everyone, known to no one. They are one of those organisms that seem to offer nothing to hold our gaze. But the more time we spend with lichens, the more they reveal their beauty, their mysteries and their strange power of attraction. Part-algae and part-fungus, lichens call into question our customary ways of classifying forms of life, and allow us to conceive of an ecology that is no longer ...