Hi! I have a question about lychen taxonomy and nomenclature, and the more I read the more confusing it seams to be. Are each species of lychens one species of algae and one of fungi or can there be many of both in one lychen? How does it work, do you identify all the different species of mycibionts and phytobionts or do you do it as a whole new thing?
This is a great question, and honestly the more I learn about lichens the more confusing they are. Here is a figure from Toby Spribille’s 2018 paper “Relative symbiont input and the lichen symbiotic outcome”:
Column A was the original view on lichens and why we originally decided to name lichens after the mycobiont - we thought that each lichen was made of a distinct fungus but photobionts were promiscuous. Column B describes what we’ve found with molecular studies looking at the mycobiont - the fungus can be promiscuous too! And column C is the hypothesis that Spribille puts forward in the paper, which I tend to agree with too - that lichens are a big ol’ mess, and there’s more going on than we’ve yet to really investigate.
However, in spite of all of this, lichenologists still tend to identify lichens based solely on the primary mycobiont and/or morphological characters (in plain English: how it looks). I think we’re at a crossroads right now where we’re realizing things are a lot more complicated than we originally thought, so where do we go from there? How do we define the lichen species? Or is that even reasonable, given that they’re a collection of bionts that can change based on where it’s growing or other conditions?
