(Toronto - July 21, 2016) Since the discovery of their true nature 140 years ago, lichens have been the poster children for symbiosis. In the textbook definition of a lichen, the filaments of a single fungus provide protection for photosynthetic algae or cyanobacteria, which in turn provide food for the fungus.
But 140 years after the term "symbiosis" was coined to describe lichen, it turns out there's a third party involved in the relationship - a yeast that may help provide the structure found in large "leafy" and "branching" lichens.