First of all, one will have to bear in mind that a species can or cannot be a real entity and this continues to be matters of debate and subject to different perceptions (or even something artificial made up in our mind!!). there are different species concepts criteria and among mycologists, most widely used ones are Morph S C and Phylogenetic S P. With respect to establishment of novel species, possibly represented by distant lineages: If u go for Morph S C, then yes, have even one striking morph that makes your taxon different is really worthy. With the Phylogenetic S P, I would try to decipher whether that taxon is really a natural unit of evolution. I have outlined some guidelines back there in 2016 to enable/guide mycologists to a certain extent (please check Jeewon R, Hyde KD 2016 – Establishing species boundaries and new taxa among fungi: recommendations to resolve taxonomic ambiguities. Mycosphere 7 (11), 1669–1677).

If you have 2-3 different key characteristics that define a genus or even 1 for a particular species, then I don’t see any reason as to why taxonomically it would not stand good. Bear in mind as well that many of our MSC have stood the test of time, with rather good support from DNA based studies. You are worried about proposing a valid species/genus if you have moderate or weak support. To me, this should not be a major concern. Taking into account as to what exists in Nature and what are available as entities in databases to compare, this should not be an issue. Even having no support at a particular node should not pose a problem if we have sufficient evidence from morph to establish taxa-whether at lower or higher taxonomic rank. As one can argue that morphological delineation can be subjective (especially based on personal opinions), same can be applied to a phylogenetic scheme. we have to understand that support is also largely based upon phylogenetic taxon sampling in your dataset, ambiguous taxa (for example those with LBA) which could lead to bias towards taxonomic interpretation.one may have full support as a distinct clade but that does not necessarily mean that we need to treat that group of taxa differently. a prior knowledge of taxonomy is crucial here to make any arrangement (unless we are dealing with OTUs).

if there is no support, but still clearly distinct, there are other aspects to look into before we make a strong case to deal with that group differently. for example, is this specific clade consistent in all phylogenies (single vs concatenated), do exclusion of taxa (especially those doubtful ones, unverified ones, those whose sequences are quite bad- at a glance once can easily decide which taxa can be excluded from a particular dataset) in our dataset affect the topology and support of our ingroup (ie studied taxa), what if I change the parameters in my analyses (for example, weighted parsimony and treat gaps as newstate- and I get support. I tried it before and it resolves even some polytomies-but this should be done with caution and need to justify why assuming that your dna is evolving in a particular direction etc...) then I will proceed towards proper understanding towards species concept of that studied group of fungi..hence morphology is important...can i support my so called new clade with any synapomorphs/apomorps to substantiate the existence of a new lineage despite no support ? I WOULD not say no based on my experience, given that in many cases, there are rapid diversification of species, especially in undiscovered habitats, unknown emerging pathogens with distinct DNA barcodes, incomplete taxon sampling, different evolutionary trajectories of specific genes used in concatenated analyses, hence in this case your studied group will not possibly have close relatives on your tree and this could lead to no support with existing members (so basically you can have an artifact/ no support in our tree)...

so many other aspects that we can comment on- as long as you can justify/validate your taxonomic concepts with appropriate scientific arguments, a species should be real!

Thank you Professor for such a elaborate and informative reply. We have followed the mentioned paper as a standard reference during our studies. Appreciate your guidance.

Thank you Rajeshkumar and Rajesh for discussing about this important subject