If anyone has ever encountered this lichen-like structure in your own country or region, please feel free to leave comments. Thanks.
These photos show recently identified Phyllosymbia, a fascinating fungus–cyanobacterium symbiosis, collected by Dr. Ko-Hsuan Chen and her team from a subtropical montane forest in Taiwan.
Our group is interested in further exploring the genomic diversity of this symbiotic relationship across different geographic regions. We would be very grateful to hear from anyone who has encountered similar structures in their region.
Very interesting article and amazing life form. However, regardless of the evolutionary background of the fungus, and the structure of the thallus, it is still a symbiosis of a fungus and a Cyanobacteria, thus meeting the definition of a lichen. Why not just call it a lichen, instead of ‘’lichen-like’’ ?
WikiPedia’s lede has “a hybrid colony of algae or cyanobacteria living symbiotically among filaments of multiple fungus species”. This system fails to meet that definition, in that it instead has fungal hyphae living within a cyanobacteria dominated biofilm.
When our knowledge advances and we find things intermediate between a group (A) and everything else previously known we have to reconsider what our concept of A is. Do we accept a new broader group, or do we tighten the definition (diagnosis) of the group, or some other choice.
For comparison the concept of what a plant is has changed greatly over the last 300 years. When Linnaeus wrote plants included fungi and to the degree that they were known bacteria. With the advent of the microscope bacteria remained as plants, and unicellular eukaryotes were forced into a procrustean animal-plant dichotomy, with photosynthetic ones and ones with hyphal morphology considered plants. First fungi, and then bacteria, were removed, as it was realised how different they were from plants. Then we lost the various eukaryote lineages with secondary plastids - we would lost Paulinella then as well if we has known of its existence. There are now three competing concepts of what are plants (Archaeplastida, Viridiplantae and Embryophyta - I don’t think that there’s significant support for Streptophyta).
We now know that the various groups of photosynthetic organisms are convergent, and that the various groups of lichenised fungi are also convergent. We responded to the former by narrowing the concept of plant to a particular clade. So far we have responded to the latter by treating lichenised fungi as a guild. We are now in a position where we have to collectively decide whether we loosen, tighten, otherwise modify, or leave unchanged the criteria for membership of that guild.