The definition of the genus Cheilanthes

[khorikhori]

Name and rank of taxon: Cheilanthes (Pteridoideae, Pteridaceae)

Approximate number of species affected: over 300

Description of change: Unify several genus of Cheilanthoid ferns into Cheilanthes: At least, Aleuritopteris, Argyrochosma, Aspidotis, Astrolepis, Bommeria, Calciphilopteris, Cheilanthes, Doryopteris, Gaga, Hemionitis, Leptolepidium, Notholaena, Oeosporangium, Ormopteris, Paraceterach, Paragymnopteris, Pellaea, Pentagramma, Sinopteris, Trachypteris

Reason for change: There are many genus of Cheilanthoid ferns are used but I'd like to have some references which could succeed to show the monophyly of the each genus. I feel there are many paraphyletic relationships. I know some lineages are clearly monophyletic such as Calciphilopteris, Gaga and Myriopteris...but the range of Cheilanthes and Pellaea are especially unclear.

Reference(s) for publication of the relevant names: Wolf L. Eiserhardt, Jens G. Rohwer, Stephen J. Russell, Jovita C. Yesilyurt & Harald Schneider (2011) Evidence for radiations of cheilanthoid ferns in the Greater Cape Floristic Region. Taxon 60:1269–1283. https://doi.org/10.1002/tax.605004

Amanda L. Grusz, Michael D. Windham, Kathryn T. Picard, Kathleen M. Pryer, Eric Schuettpelz, and Christopher H. Haufler (2021) A drought-driven model for the evolution of obligate apomixis in ferns: evidence from pellaeids (Pteridaceae). AJB 108(2): 1–20. https://doi:10.1002/ajb2.1611

Is this change already in World Ferns? No

List the numbers of any issues with which this one interacts: none

[joelnitta]

So is this proposal to basically create a very broad Cheilanthes that would subsume all genera that currently render Cheilanthes paraphyletic? That seems somewhat extreme to me, but I am not a specialist on this group, so I hope others can also comment. (NOTE: this issue, and this repo, is for testing purposes only).

I will also demonstrate some other features of comments in issues: you can mention someone by typing @ and their username, like @khorikhori: @khorikhori. You can also link to an issue by typing # and the number of the issue like #1: #1

[khorikhori]

@joelnitta #2 The system of Github PPG is working well and I received your comments by an email now. In addition, I'd like to hope a function of uploading data files (.fasta, .nexus, .bay etc.) in this Github system to show some evidences to support some user's comments. But to do this, now a user have to upload the data files in some server and paste the link here ?

[joelnitta]

The system of Github PPG is working well and I received your comments by an email now.

Great! Yes, you should get email notifications about any issue you create or comment on.

In addition, I'd like to hope a function of uploading data files (.fasta, .nexus, .bay etc.) in this Github system to show some evidences to support some user's comments. But to do this, now a user have to upload the data files in some server and paste the link here ?

While that would be possible, it is not really the purpose of the GitHub repo. Most likely the only file that will be included in the repo is the CSV file including all of the taxonomic data, in other words, the taxonomic database. If you want to share other files that relate to a particular issue (taxonomic proposition), I would indeed suggest posting them somewhere else (such as Dropbox) and providing a link in your comment.

Although, it may be a good idea to establish a central place to put such files so that they don't disappear in the future. For example, we could make a google drive account for PPG.

[algrusz]

So, for the sake of practice, if we would like to provide a response (or an argument in opposition) to a suggested change, would we do so here as text? Or, is there a place to "up vote" or "down vote" an issue?

Also, thanks for putting this together, Joel!

[joelnitta]

@algrusz at the top of each comment, there is an icon you can click on to add a reaction (I did so for this comment).

There are a limited number of reactions available, but they include thumbs up / thumbs down. So that is one way you could "up vote" or "down vote" an issue (note that it will not affect the placement of the issue in the issue list - that is by reverse chronological order and open/closed status).

Also, adding a reaction like this does not count as voting. We plan to carry out voting separately from the GitHub discussions. Most likely the link for the voting will be sent to the mailing list for each round of voting, then the results will be posted to the GitHub discussion (issue). This means anybody can view the discussions, anybody with a GitHub account can comment on the discussions, but only people on the mailing list can vote on the taxonomic proposals.

If you feel one way or the other about a particular taxonomic proposal, I think it would be better to add a text comment rather than only a reaction emoji. That way members of the community will have a chance to understand why you disagree or agree, not just see disagreement or agreement.

[choess]

@khorikhori you may want to look at some of the more recent publications by Ponce & Scataglini (2016 and on) which have made significant progress in cheilanthoid classification (https://doi.org/10.1007/s13127-018-0366-6 and https://doi.org/10.1111/jse.12723). You are correct that Cheilanthes and Pellaea in the broad sense remain polyphyletic "wastebasket taxa"; while the general trend has been to narrow their circumscription towards monophyly, this process is still far from complete.

Recombining all of Cheilanthoideae into a single genus to achieve monophyly would necessitate combinations under the most senior genus, Hemionitis (rather than in Cheilanthes); this program was largely carried out by GLOVAP in 2018.

To editorialize a bit, that classification does not seem to have enjoyed much popular success. Loosely speaking, the dumpster fire of homoplasy in the cheilanthoids generally gives us the choice of defining large monophyletic genera that lack morphological coherence, or small monophyletic genera, some of which are very coherent and some of which are nearly indistinguishable. Most pteridologists of my acquaintance seem to be content to treat it as a work in progress and hope that characters will gradually be found to erect new genera until monophyly is achieved. I think a program of lumping to achieve monophyly here would not be likely to achieve support, even a more modest one consolidating genera into the clades laid out here: https://www.jstor.org/stable/25639813. But I would not claim to speak definitely for the community, nor wish to deter you from making a proposal that you feel to be justified.

[khorikhori]

@choess I apologize for my late response. Your comments are valuable to me, and I appreciate your insights on the taxonomic status of the genus Cheilanthes. I look forward to future studies that will provide new knowledge for pteridologists.