[PREFACE: I have erred on the side of @ tagging a lot of people here - feel free to ignore if this topic isn't of interest to you.]

The generic classification of Poaceae Tribe Stipeae in POWO appears to be fairly mature at this point, although there could still be a few pending changes in the larger genera.

Meanwhile, iNat taxonomy for the needlegrasses remains a mess.

-- 41 species are currently duplicated in multiple iNat genera.
-- 136 of the 370 iNat species taxa (37%) currently deviate from POWO.

This spreadsheet shows the current (as of 2021-02-26) crosswalk between iNat species and POWO species. There are two sheets, one sorted by POWO name, and one sorted by iNat name. I did not drill down to subspecies and varieties, since the main purpose here is to decide whether we are going to curate toward the classification of genera reflected in POWO. Any eventual taxon changes will need to deal with any subspecies also.

I would like to start curating toward the genera now accepted in POWO (see spreadsheet), mainly so that we have a guidepost for consolidating the duplicated species in iNat, and just to get everything on a consistent footing for now. While recognizing that this will likely not be a final "stable" classification, I don't think that the current mess should have to wait for that magical day.

If we do this, however, I know that us North American users would have to get used to unfamiliar names for most of our needlegrasses (Peterson et al. 2019). This may be true on other continents too, so let's have some discussion first. If anyone knows of a different world-wide classification of Stipeae that would be better for iNat to follow, please provide a link or other access information so that we can evaluate.

I have already added draft taxon changes for the current "easy" scenarios, where curating toward POWO would not affect any observations (at least at the species level) and the POWO name is already available in iNat. These are in a change group named "Stipeae2021" along with three pre-existing but uncommitted changes, and are also reflected on the spreadsheet.

Please @ tag additional interested users that I might have missed below.

Authors and commenters on open Stipeae flags:
@abedggood @aspidoscelis @bouteloua @charlie @cmcheatle @coreyjlange @jdjohnson @kitty12 @kokhuitan @loarie @marigoldjoy @melodi_96 @mftasp @oscargsol @yargeritaville

More authors of past Stipeae taxon changes:
@choess @faerthen @hanly @jaykeller @kastani @najera_tutor @pjd1 @rfoster @sanguinaria33 @silversea_starsong @stephen_thorpe @stevejones @tonyrebelo @wdvanhem @xpda @zroskoph

More key identifiers and observers of Stipeae by continent:

Oceania: @david_lyttle @jon_sullivan @knicolson @knicolson @lloyd_esler @mark_smale @mattintas @meurkc

South America: @aira_chilensis @alfredo_f_fuentes @anibalakd @david1531 @mateohernandezschmidt @preli

Africa: @abounabat @daverichardson

Europe & Asia: @aleksandrebel @alexanderdubynin @allaverkhozina @alzov @apseregin @ariel-shamir @davydovbotany @fragmansapir @igor_olshanskyi @pavel_golyakov @vadim_prokhorov @yanghooncho @yury_kopylov-guskov

North America: @cwbarrows @efmer @glmory @grnleaf @jrebman @lysandra @prairie_rambler @rickwilliams @rojosmojo @sambiology @sedgequeen @sheriff_woody_pct

POWO still doesn't accept Hesperostipa for some reason, so I followed up on some old flags and entered deviations. There are a few pending taxon changes for Hesperostipa/Stipa duplicates.

I also agree on treating each infrataxon as individual cases, POWO frequently just lumps them with the species willy nilly.

Apparently infraspecies are not willy nilly: they are the ones that have changed status in some way (changed rank, or changed parent or have been synonymized). Otherwise they are not included, although there are plans to include infraspecifics in the future.

@abounabat ok.... but the idea was that we were going to wait to be sure there is community agreement first to follow the genera used by POWO. Hopefully that will be the case...

So I'm trying to wrap my head around the issue with infraspecific taxa that several of you have brought up.

1-- In my experience, there are a lot of infraspecific taxa in POWO, old and new, most of which are in synonymy under other taxa. Are you saying that there are a lot in current use elsewhere, but that are missing entirely from POWO, even as synonyms? (I do see that's the case for Stipa dregeana varieties.) Maybe my experience is biased because North American infraspecific taxa were incorporated disproportionately to other parts of the world (from the old Gray Herbarium Index)?

2-- in many cases when POWO accepts infraspecific taxa, they have not (yet) created a taxon for the autonym (=nominate infraspecific taxon). In such cases, the synonyms that would be assigned to the autonym are instead just listed under the main species, for lack of another place to put them.

3-- in many cases when species with infraspecific taxa are moved to new genera in POWO, the combinations for the infraspecific taxa have not (yet) been published under the new genus, so POWO can't list the infraspecific taxa as accepted in the new genus.

When POWO lists infraspecific taxa as synonyms under any of the three cases above, it would be hard to say whether or not that is a conscious taxonomic decision on their part, without asking about each individual case.

In cases like #3 above, when we still want to recognize the infraspecific taxa, that would be a good argument for deviating from POWO and not moving a species to its accepted genus.

Am I missing any other issues?

@abounabat I hear you about the term "deviation." I have slowly learned that "deviation" has a very specific meaning in iNaturalist, which is any difference whatsoever between iNat taxonomy and the names listed (or not listed) in POWO (or other taxonomic authority). That includes, as I've been told, autonyms that are implied by other accepted infraspecific taxa, but are not actually listed in POWO, and also names that are just completely missing from POWO.

I can explain the issue with infraspecific names and POWO: the POWO Poaceae dataset was originally a copy of GrassBase. Derek Clayton did not have time to treat infraspecific names globally for GrassBase, and he did not consider them to be important. So they are not rejected, they are just not dealt with properly.

Thank you for updating the grass classification on Inat @jdmore, let me know if I can help. If there are big errors on POWO I might be able to get those updates made. The POWO compilation deliberately chose not to follow to recent publications in the Stipeae which I disagree with, you are right to update these.

Some history is explained in my paper here https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4408733/

As @bouteloua mentions, POWO doesn't recognize Hesperostipa, putting them at odds with both researchers on the tribe and regional floras. Following Peterson et al. is probably the best bet.

Personally, of course, I would ignore POWO entirely. :-)

@tonyrebelo this is not the case, POWO lists autonyms for very many taxa, and is missing a lot of others. I don't think they choose explicitly to exclude them at all. In my experience when linking our taxa to POWO, it's about 50/50.

I do not think POWO prioritises infraspecies to the same degree as species. @jdmore, in my experience: POWO has not captured many infraspecies altogether that are in current usage in the taxon's range. In other cases POWO explicitly treats separate infraspecies as synonyms of the parent species, even though the infraspecies are in current usage throughout the taxon's range. It can be difficult to find the reason why.

Deviations are any taxon that is in iNaturalist and is either not in POWO at all, or we have decided to treat differently to how iNaturalist treats the taxon. This means that yes, all autonyms missing from POWO are by necessity deviations.

Finally, in my experience, names from non-English-language literature are less likely to have been captured by POWO that those in well-known English-language publications.

@mftasp - POWO has changed its policy about infraspecies, but it will be many years before it approaches completeness, and in the meantime it cannot be regarded as comprehensive or definitive regarding infraspecies.

Another issue with POWO as a database, its its use of IPNI. We have had three cases in the last year where species were rejected because of code issues, but these rejections are not explained, documented or communicated. One that was rejected three years ago was because of a proofing error, where a line was omitted in publication that included the word "Type" and therefore rendered the name typeless. It was only detected during posting deviations on iNaturalist, and the authors of the name were totally unaware of any issues with the name. POWO only accepted the name after an erratum was published, but the real issue is the lack of transparency, referencing and feedback on these decisions. In another case a name in use for over 200 years in the Cape Flora has been designated invalid in the last three years, without any documentation, explanation or notes. The reason turns out to probably be valid, but no one using the name would even now be aware of the issue where it not for an Australian MS that misused it (and thus cited a wrong locality for this extinct species, otherwise it would not have been detected).

@jdmore : I dont think hopping from publication to publication is "stable" - if POWO is not acceptable then rather revert to Grassbase or Grassworld, and if they are equally problematic, then we may as well stick to POWO.

Personally I dont think that these generic reshufflings are that important: the species are not affected, and the synonomies on iNaturalist work very well at coping with alternative names. However, that assumes only one instance of any species in the dictionary, and not duplicates under the different genera.

In my experience POWO is reasonably fast (less than a week turnaround) with all issues I have raised. This includes local journals - it is not just non-English language publications that POWO is slow to harvest.

I agree with Maria Vorontsova"s "In my opinion the best option for the iNat community is to continue working closely with POWO "

on grasses and everything else. I think if we accept (and enjoy!) that we are in the midst of a time of rapid discovery, and go with it, accepting the changing taxonomy that goes with increasing understanding, that will be our best forward path.

@aspidoscelis the difficulty is that rearrangements have been published using a limited subset of regionally common species that were available for sequencing/study. But in order to make full changes POWO needs to make a decision and implement it for a ALL species within e.g. Stipa sensu lato. But many species from inaccessible places have not been included in the new combinations and published rearrangements, so there is no clear place and name for them in the new system. This is why large groups with a global distribution always lag behind

Inevitably these compilations do rely on specialists to email in and ask for the changes to be made, backed up by papers

This tendency to treat or present scientific questions as matters of institutional fiat really rubs me the wrong way. Frankly, I think it's anti-scientific.

You had a purpose in mind other than general expression of disgruntlement?!

Hesperostipa (specifically, Hesperostipa comata, Hesperostipa neomexicana, and Hesperostipa spartea, all placed by POWO in Stipa) is the only anomaly I see for the New Mexico Stipeae in POWO.

Speedy Rafaël already responded - essentially it's on their near-term to-do list. He cited all the things Maria listed above and said it should be updated sometime this year.

I have this on my to do list and am in regular contact with Rob Soreng from the Smithsonian who manages the Catalogue of New World Grasses. We did over the past year try and sort Panicum as much as possible even though many species still are not in the right place as names have not been published. We hope to do this with Stipa this year as much of the New World has now been sorted and much has been published on this recently though uncertainties remain and numerous species lack a name in a correct genus [...] I will check with Rob and Maria Vorontsova with whom I consult on generic circumscriptions in grasses to see where we are and if changes can now be made with confidence.

? Perhaps prioritize the duplicates?

Hi all, just a heads-up that I will be committing all of the changes for the New World and Southern Hemisphere genera in about 24 hours, unless there are any last-minute concerns. This will bring iNat species into alignment with POWO for the genera Anemanthele, Austrostipa, Barkworthia, Eriocoma, Nassella, Pappostipa, Piptatheropsis, Piptochaetium, Pseudoeriocoma, Ptilagrostiella, Stipellula, and Thorneochloa; maintain a deviation for the genus Hesperostipa; and clean up a few inconsequential deviations in other genera.

There are fewer changes needed for the remaining species of genera centered in Eurasia (Achnatherum, Chionochloa, Macrochloa, Neotrinia, Patis, Piptatherum, Ptilagrostis, Stipa), but am holding these for a second batch of changes, since it seems like these genera may have more revisions pending for POWO. If you all think it's better to go ahead with them now, though, I'll set up the changes. These would be the ones with yellow highlighting on the updated spreadsheet.

@jdmore Is this resolved? Any reason to keep the flag open?

I can help with some of it. Might be best to start a new flag and describe what needs to be done there.

Thanks! Last time I looked, I wasn't sure that Stipa s.s., Achnatherum s.s., and other Eurasian genera were fully resolved yet, so proceed with caution if you decide to tackle those.