Fifteen years ago I had an odd dream. In it, a medicinal plant that I was interested in, an Usnea lichen that is ubiquitous on trees throughout the world, told me that while it was good for healing human lungs it was primarily a medicine for the lungs of the planet, the trees. When I awoke, I was amazed. It had never occurred to me in quite that way that plants have some life and purpose outside their use to human beings.