Should curators have a critical point of view when changing iNat taxonomy?

Taxonomic backbones are surely something very useful for our taxonomic treatment of taxa. Anyway, there are more and more flags by users asking for a treatment that is different from the one that aligns with the taxonomic backbone. Moreover, sometimes it happens that taxon changes could have a somehow “destructive” effect on observations implicating a deletion of hundreds to thousands identifications. Some of these taxon changes are created and committed by just one curator and, in some cases, no other users have been asked to provide a point of view on such taxon changes. A number of these taxon changes appears questionable, if not sometimes wrong, from a taxonomic point of view despite being totally in agreement with the taxonomic backbone.
So, I wonder if it would be desirable that curators should have a critical point of view on the subject that they are going to treat from a taxonomic point of view.
As regards, I think that three “virtuous” practices could be a) checking if the taxonomy of the backbone is adopted in the various treatments of a given taxon in recent manuals and papers; b) in the case researchers and experts treat that taxon in a different way from the backbone, check in literature who could be “right”; c) ask other users (top observers, top identifiers and known experts) for a point of view.

What do you think?


I’m not a curator but in the case of plants, POWO is often followed without considering the practical consequences of making the change. IMO, curators should be required to involve the community before making a disruptive change.

In retrospect, there have been numerous recent changes to plant taxonomy that should not have been made. A more conservative approach is sometimes warranted. Just because POWO makes a change does not mean it’s the best option for iNaturalist. I’ve interacted with POWO many times, and as far as I can tell, one person makes all the decisions. POWO is a necessary baseline, but it is not doctrine.


[Plant curator]
Hi, i agree with you. Basicaly because i did one change i “regret” when i became curator ; it was completely valid according to POWO and i understood the paper based on, but i didnt take a step back with others curators opinions and crossing with another sources. It was actualy a wrong change.
Now the process is much clearer to me thanks to other curators and curator experiences stacking.

But honestly the curator guide could be more explicit about the process steps you are mentioning.

Also POWO is listed as the only authority for vascular plants with possibly deviations. Deviations sources, context etc. should be clearly explain; For exemple we all know for ferns iNat is basicaly following PPG I and not POWO


I did not mention one particular backbone for some reasons. First of all, this is not an accusation towards any backbone. I know that those that are behind these databases have to deal with a very huge size of data and it is understandable that there can be issues. Moreover, at least some of these backbones are not fixed but update their taxonomy and are keen to receive suggestions.

I did the same, made a major taxonomic change referencing POWO which in retrospect was completely impractical and annoyed a large number of people.

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The Billings’ sedge saga is a prime example of why its important to have a critical lens over simply following a single taxonomic authority. A perfectly valid species widely recognized by regional experts is swapped for a subspecies based on POWO taxonomy, then subsequently re-split 7 months later based on updated POWO taxonomy which necessitated the creation of a new taxon and relegating the original C. billingsii (which was perfectly good) to inactive status.


Agreed, with small inconsequential taxa it’s fine to go ahead and make changes, but if there’s any reason to think that other users might be quite confused or frustrated by the change then it’s a good idea to consult and/or explain it to them before the change happens. The best way to do this is probably making a flag on the taxon, explain your justification, and then tag the top identifiers and observers of the taxon.

This leads to discussion in which everyone comes to understand the issue better and better decisions can be made. In the case of POWO I’ve experienced it where a disagreement in the iNat discussion leads to someone reaching out to POWO to resolve some confusion, and then POWO made changes which iNat can then follow. If it’s a complex taxonomy issue though this process can take ages if there’s a lot of disagreement or if no one is especially motivated to make progress with the change.


Carex billingsii and C. trisperma var. billingsii both existed simultaneously, so an atlased swap would have been necessary regardless.


I recently started ID’ing fungi, and I learned that there isn’t an equivalent of POWO for fungi. I also found one journal post saying that for fungi, the taxonomy is a free for all. I’ve encountered situations where there’s disagreement on an ID for a fungi observation that is more about the taxonomy than about the organism in the observation. It seems that recent genetic work, much of it not necessarily even published or peer-reviewed, is presenting a different picture of species and genera than what is found in most books and that iNat identifiers have used in the past.

It makes me think we really need some structure around taxonomy that is owned by iNat but that allows for a long period of commentary and discussion before final changes are made. Otherwise, I think there are going to be a lot of upset people as identifiers with different taxonomic models in their minds try to reconcile IDs.

I would urge a cautious approach to taxonomy changes and would fear the disruptive effect of chasing the latest research, but I’m worried that some enthusiatic iNat professional mycologists are already forcing the issue by identifying according to their understanding of the latest research - but without any formal body reviewing it, approving it, or adopting it. It could be very discouraging if this continues.

I should add that much of the genetic-based taxonomy is going to make it harder for identifiers, because species could be split up depending on genetic characteristics that won’t be obvious in photographs.

In the plant world, there’s a similar controversy about American nettles. Someone split American nettles from European ones. They used to be Urtica dioica, but now the American nettle apparently should be called Urtica gracilis gracilis (a subspecies, no less). However, no past observations were ever changed, so there’s no consistency in the dataset over history.


This first paragraph is absolutely true, and across many taxa. It’s been turning 300 years of morphology on it’s head. And sometimes there’s push-back.

There are conundrums: when do hybrids become species? There is precedent for describing recombinant hybrids as species, and some of us are wondering when it stops. I’m at a crossroad myself- do I describe a recombinant hybrid as a species? Do or don’t I’m going to PO somebody.

On the latter paragraph: welcome to my world. I have to go through iNat observations manually, one at a time, to see which are correct; in one subset filtered, 100% of observations were wrong. The problem largely lies in morphology that is detailed, beyond what most people catch in photographs.

The problem with departing from IUCN or an established taxonomic list is it becomes impossible to maintain.

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Generally, the community is supposed to pick “senses” (sensu) to apply to taxa. I would say it’s actually encouraged to go with sensu lato approaches to split taxa that haven’t yet been given proper attention in the primary literature. I’ve run into this issue a few times in the past few months with a number of fungi identifiers attempting to move taxa into sensu stricto without proper replacement taxa for the displaced observations, which is certainly frustrating. I think observation fields may be better for the uses intended by these identifiers.

Urtica dioica is one of a few problem complexes that have yet to be split out due to changes being accepted before range maps are fully developed. Other examples are Campanula rotundifolia, Stachys palustris, Ranunculus aquatilis, Opuntia humifusa, and Viola sororia (Not saying the split taxa in these groups shouldn’t exist on iNat, just that they present enormous difficulty in determining which sense to apply without a taxon split officiating the move to sensu stricto).

The eastern North American subspecies of Urtica gracilis is ssp. gracilis, but there are two other subspecies in North America.

Agreed. As most of you know. POWO itself is much off the rails with taxonomic revisionism and splitting, and iNat curators have gone even beyond that with adding ‘new’ species splits based on non peer reviewed papers and such. I recognize that for a lot of people it’s important and exciting to follow the latest trends in taxonomy, but i dont think some curators realize how badly it breaks the site for everyone else - not only casual users (who the site was built for by the way - not taxonomic specialists) but also applied ecologists and basically anyone else who isn’t a taxonomist. it’s a real crisis and getting worse almost every day. I really do fear it will destroy iNat soon. That may seem overdramatic… but hey i hope i’m wrong too.

There isn’t a taxonomic backbone, it is shattered. taxonomy is horribly broken beyond iNat right now as well. Really the only solution is to roll back a few years and then freeze taxonomic changes until there’s some stability at which time a bunch of changes can be made at once with consistent documentation. That’s hard, but i don’t see anything else working here. And the iNat curators need more organization, too many of them go rogue and the fact that taxonomists also are the majority of the moderators on the site has created some major issues.


(not a curator, just a fungi enthusiast)

There might not be a specific equivalent to POWO, but there are resources like Index/Species fungorum and Mycobank that at least attempt to keep track of what the currently accepted names of species are and what the synonymy is.

America has a bit of an issue with fungi since there’s so many species that were just named after European lookalikes, so of course DNA is showing that its not the same species, and papers haven’t yet caught up. Or we have situations like the American Amanita muscaria group, where the various American varieties (guessowii, perscina, etc) are being clearly shown through morphology and DNA to not be the same species -… but a comprehensive study needs to be done on the genetics and other characteristics of our American species. For that particular one, if you go on forums, most people have come to consensus that A. chrysoblema and A. muscaria guessowii are synonyms to a fungus that just has a lot of variability to cap color, with chrysoblema taking precedence because it is the older name. But we don’t have a good peer reviewed paper yet, so guesowii hasn’t been combined - which I think, DOES show that fungi curators are taking a conservative approach to this in general.

Mostly sequencers use observation fields to keep track of specimans which have similar morphology - often, we don’t have access to the genetics of the type specimans for what we’re looking for (they either haven’t been sequenced yet or they’re so old that the DNA is degraded) so we’re waiting for a paper to come through that correlates a 100+ year old description with our modern understanding, or someone to study these groups of correlated specimans and describe it as something new.

Most of the fungi crowd seems to be pretty chill and also very aware of the taxonomic mess that a lot of fungi are in.


Again, I can only speak regarding plant taxonomy on iNaturalist. I agree that the curator guide needs work in a number of key areas but unfortunately I don’t see that happening any time soon, nor am I confident it would have the desirable effect.

There needs to be one person in the primary role of reviewing every proposed change, similar to the way software modifications are now handled. That person probably needs to be a full-time staff person with no other tasks, that is, that person would be an enabler, not a blocker. This is the best way to restore some semblance of order to the current situation.


First of all: You should always conduct a discussion among people who are knowledgeable about the topic! Secondly: It is important to remember that taxonomic changes published in the professional literature become scientific fact only when they are widely accepted by the community of experts in any given topic; that is why, for example, in the field of biological nomenclature, we sometimes have several approaches to a given topic, each represented separately by outstanding scientists, then it is impossible to establish one framework because it does not exist, and there are two, sometimes three different opinions on the same taxonomic topic. These are truly very complicated issues…


No-one would have breadth of taxonomic expertise to do that well. They would only be able to do what curators should be doing anyway - generating a conversation around any impactful change with the users who understand the taxon. They would then inevitably also be an impediment to the many basic changes that don’t need so much consultation.


yes but who makes that call? Right now the system isn’t working well… very dramatic changes are being made that a lot of people don’t agree with.

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If this is true, then it cannot be considered a scientific approach. Peer review exists for a reason.

Even the smallest change can have negative consequences. For example, a trivial name change (say, from -folium to -folia) inadverantly reverts every disagreeing ID involving the old name. In some cases, hundreds of observations may be affected. Finding and fixing them is anything but straightforward.

I don’t know what’s happening outside of plant taxonomy, and of course my involvement in the flagging process is limited, but in my experience, curators do not routinely involve the community. Numerous changes have been made under the radar. If a top-level reviewer (of proposed changes) did nothing more than enforce a community-based decision-making process, we would probably see an immediate improvement.

More importantly, a top-level reviewer would help promote a much-needed cultural shift. Instead of viewing POWO as an absolute authority, the reviewer would promote a more deliberate process that validates taxonomic change in light of its effect on iNat users.


These 3 are all excellent practices and I think we should consider adding them to our curatorial guidelines, at least as best practices. In particular, as our user pool has grown immensely, we quite frequently have access to group experts, even if they’re not prodigiously active observers or identifiers. (e.g., in the case of the Carex sectional rearrangement this year, one of the coauthors of the paper in question showed up to say that the groups presented as “clades” without formal rank were provisional and shouldn’t really be incorporated into our taxonomy.)

I would also add that there should probably be some sense of proportionality: if a taxon swap is going to affect thousands of observations, there should be more deliberation, announcement through multiple channels, and so forth before committing the swap, when compared to something that will affect 5 observations. Even a well-accepted and well-supported change on that scale is going to be disruptive if it comes as a surprise.