As a child I was intrigued by lichens. New Zealand has over 2000 lichen species, yet they are seldom included in biodiversity surveys. My desire to publish an illustrated guide led to exploratory trips from Northland to the Subantarctic Islands. Along the way I discovered several new species, and showed that lichens are rapid responders to climate change. At the International Lichenology Congress in Helsinki, with an expedition to Lapland, I learned that lichens are sensitive indicators of pollution. Some have survived over a year exposed to outer space. Lichens are crucial to nearly all terrestrial ecosystems – and infinitely fascinating!