A beginner's guide to the lichens of the world.

A series of illustrated character studies based on the kinds of lichen growing quietly all around us — on walls, rooftops, gravestones, tree trunks. Easy to miss, but once you start noticing them, they’re everywhere.

Each of the 18 characters is based on a real species. Match them up, go lichen-hunting, or just start noticing them next time you’re out and about.