Lichens: ecosystems unto themselves. They’re diverse, apparently ubiquitous, and foundational to life on terrestrial earth. But this episode isn’t really about lichen. It’s about an endangered species that relies on a lichen diet – a diet that is disappearing as fast as the old growth forest in British Columbia.
What do you do when you find the last individual of a species previously thought to be extinct? The two rarest plants on earth both live in the Presidio of San Francisco, they’re both in the same genus, and there’s only one left of each. Is there a future for these species, and if so, what does it look like? And what can species on the brink tell us about ourselves and the future of our ecosystems?