Flag for Taxon: prostrate grapefern (Sceptridium lunarioides)
| Flagger | Content Author | Content | Reason | Flag Created | Resolved by | Resolution |
|---|---|---|---|---|---|---|
| sbrobeson | prostrate grapefern (Sceptridium lunarioides) |
it is a synonym of Holubiella lunarioides (Michx.) Skoda |
Mar. 7, 2023 00:21:41 +0000 | kai_schablewski |
resolved, see my comment |
Comments
There is a deviation in place How does this affect your thinking on this flag? https://www.inaturalist.org/taxa/355635/taxonomy_details
And if you would like this changed, please contact bi@kew.org to request a review.
The basis of iNaturalist's deviation (the PPG I classification) is the same as the starting point for the Zhang et al. 2020 paper I cited. Based on their recovered phylogeny, they recommend going one step further and using Skoda's generic name of Holubiella.
Do you mean to contact the listed address in order to change the iNaturalist taxonomy, or the POWO listing?
@kai_schablewski @choess maybe this is not worthwhile to split? But the cited paper postdates the PPG classification by several years, thus is more up-to-date.
These two sources usually follow the PPG1 classification and the classification changes that have occured after that:
https://www.worldplants.de/world-ferns/ferns-and-lycophytes-list#plantUid-1627
https://www.pteridoportal.org/portal/taxa/index.php?tid=963
Both still accept Sceptridium lunarioides and worldplants lists Holubiella lunarioides as a synonym.
This might change:
Assessing Morphological Species and Interspecific Relationships in North American Grapeferns (Sceptridium; Ophioglossaceae) Using ISSR Markers: https://www.ingentaconnect.com/contentone/aspt/sb/2022/00000047/00000003/art00009?crawler=true
Based on the genetic evidence we might change it if you all agree, I am fine with that. Or we wait until other sources also accept it.
Support for this change is recent, so it makes sense that checklist sources have not yet picked it up. I would say that it's better to be proactive and change it -- the fairly deep divergence between Holubiella and Sceptridium depicted in Cao & Hauk 2022 supports Zhang et al.'s reassertion of Skoda's classification. (I would be willing to recuse myself if necessary, but I was not involved in any of the cited research.)
Taxonomic swap committed: https://www.inaturalist.org/taxon_swaps/124002
@sbrobeson Contacting POWO would potentially lead to them updating their taxonomy, which we follow.
@kitty12 Thats not very likely. No, we do not follow POWO for lycophytes and ferns because POWO does not follow the PPG I system from the Pteridophyte Phylogeny Group and most of the more recent changes based on that system. POWO follows its own very lumpy approach. It is possible that they accept at least some new taxonomic changes, but this is far from certain.
In general, POWO mainly sources its information from checklists -- which can be relatively out of date with regards to names, especially for traditionally over-lumped groups like non-seed vascular plants -- and does not make exceptions based on ad hoc requests. I would be shocked if an email from me or a similar third-party individual managed to get a change implemented, and if it did, it would take a whole flurry of emails to change everything that needed changing.
Eh. The molecular results establish this species as basal to the rest of Sceptridium, but that genus is monophyletic whether or not Holubiella is split, so they don't provide a definitive basis for recognizing the latter. I would have waited on this (Alan Weakley, who is usually pretty splitty, hasn't taken this up), but PPG II is in progress right now; we can revisit this if it fails to recognize Holubiella.
POWO will generally entertain correspondence on taxonomic updates relevant to individual species or genera, but their fern and lycophyte taxonomy is somewhat out of step with most use for somewhat political reasons I don't want to rehash and unlikely to be reconsidered in the immediate future.
Nice to hear that PPG II is in progress. I also believe that this is more of a political decision by POWO and that PPG II will not change anything about it.
However, what bothers me is that we still allegedly officially follow POWO as the only authority for ALL vascular plants including lycophytes and ferns according to the Curator Guide:
"External Taxonomic Authority List:
...
Plants (Plantae)
The taxon framework that covers the accepted plant phyla is based on the Catalogue of Life 2018 Annual Checklist but Catalogue of Life's status as an authority does not extend past those phyla. We do follow authorities for the phyla listed below:
Vascular plants (Tracheophyta): Kew’s Plants of the World Online (POWO) with deviations described here. "
The fact that we do not actually follow POWO for these plant groups but the Pteridophyte Phylogeny Group is often not known to everyone and will continue to lead to misunderstandings in the future.
If taxonchanges are sometimes carried out according to POWO and then have to be reversed, it's just annoying for everyone involved.
In my opinion, it should finally be written explicitly in the Curator guide that we follow the Pteridophyte Phylogeny Group for lycophytes and ferns.
Furthermore, it would make sense that taxon framework relationships for these taxa are not longer sourced to POWO.
Perhaps we should wait and see whether POWO joins the scientific majority and switches to this system with the release of PPG II, but I don't think this is very realistic.
I would agree that I would prefer to avoid using POWO's largely GLOVAP-based classification for ferns and lycophytes; apart from the taxonomic merits, they have not kept up with alpha-taxonomy, so many new species in the broadly-circumscribed GLOVAP genera have no published name in that genus.
@loarie has indicated that he feels the current system of deviations from POWO is unmaintainable, but I'm not sure whether he means that in social or technical terms.
I don't know how long PPG II will take to complete now that the process is underway, but hopefully it will produce either a free-standing website or take over fern & lycophyte authority on WFO, so that there will be a website with persistent identifiers that can be used as a taxon authority for those two groups.
If PPG would make available their taxonomy in a machine readable updatable format like POWO and be responsive to inquiries like POWO we could carve off a separate taxon framework for ferns etc sourced there. But for now all vascular plants are sourced to POWO and deviations more extensive than ones involving a few species are difficult to maintain.
setting aside matters like the mire created by GLOVAP etc., it is true that Holubiella wouldn't really merit recognition as a segregate given its placement simply as sister to monophyletic Sceptridium, but it seemed notable that multiple groups working with grapeferns today (per e.g. articles linked in this flag thread) have gone to the trouble of using that name. it seemed useful to keep with contemporary usage given that iNaturalist does not follow POWO for ferns/lycophytes regardless. if nomenclatural stability is preferred when rearrangement is not strictly necessary to attain monophyly of genera, I understand.
Molecular evidence has supported the previous elevation of this species to a new genus. See https://onlinelibrary.wiley.com/doi/10.1111/cla.12408