Where can I find documentation for curators describing how to properly subdivide a genus? I’m not a curator but knowing this will help me write better flags.
I am working on a plant genus that lacks complete phylogenetic data. However, the genus was subdivided into two sections in 1849 based on morphology. Every identification key I’ve looked at starts by subdividing the genus based on section (without mentioning the section names). Does iNat allow infrageneric subdivision based on morphology alone?
Each taxon rank puts a bit of load on iNat’s servers, so there’s a general preference to avoid additional levels unless it really helps with identification. So if it’s a small genus with not a ton of species then it may not be worth it. But there are many genera where it would definitely help. I’ve helped or attempted to help with getting infrageneric taxonomy implemented for a number of plant genera. POWO is iNat’s source for plant taxonomy but doesn’t cover infrageneric taxonomy which means we need to use other sources. The challenge is that iNat needs the taxonomy to be global, and many sources will only cover the taxonomy for a particular region, and the taxonomies for different regions may well conflict with each other.
If there is academic consensus about which species are in which sections then you can create the subgenera/sections and change the parent taxon of each species to the appropriate parent. If it’s a large genus and you have a lot of species and different sources, it might help to create a spreadsheet to organize and collaborate on the process. We did that with Salix and it worked fairly well.
Personally I’d prefer using whatever taxonomy there is that covers an entire genus even if it’s old and morphology-based, but a lot of curators will disagree. If the last revision of the entire genus was in 1849 and it’s a well known genus, it’s possible that phylogenetics has messed up the old morphology-based taxonomy, and most curators will want to follow the phylogenetics. That’s been the main hindrance for some genera (e.g. Cladonia, Potentilla) where the phylogenetic work has been fairly recent and hasn’t reached a formalized resolution yet.
I’m also not a curator, but the curator guidelines on this topic can be found here: https://www.inaturalist.org/pages/curator+guide#nodes. This probably doesn’t clearly answer your specific question, but in my experience infrageneric nodes are acceptable as long as they are (1) published and (2) comprehensive (that is, all species in the world within that genus can be assigned to one of the nodes). The latter criterion can be a problem with complex genera that span continents - often regional treatments propose splits, but don’t consider the entire range of the genus. For example, see this flag for Artemisia, for which some subgenera had been created but there was no comprehensive list of what species belonged under them, so 5 years later there is a mess with several subgenera but many species still unassigned to any of them.
If you think infrageneric taxa would be helpful (and stable + comprehensive), especially for IDs, just flag and ask!
One idiosyncrasy of the site to watch out for – it’s very easy for curators to silently change the meaning of infrageneric taxa by changing the makeup of their constituent species. This is because it is possible to rearrange the makeup of an infrageneric taxon without going through the formal taxon change process.
For example, I used to use the subsections of a large plant genus – as presented in FNA – pretty extensively, especially for some groups of species where the individual species are very hard to distinguish from photos, but their subsection assignment is unambiguous. I felt like this was better than going all the way up to genus, and the subsections represented traditional groups of species that had been quite stable for many decades. Then, a few years back, more recent research was published that rearranged the makeup of several of the subsections. Unfortunately, a well-meaning curator very quickly updated the subsections to reflect their new makeup without committing any formal taxon changes. This silently rendered hundreds of my IDs incorrect, because they now represented the “new sense” subsections, even though I had applied them in the “old sense” (at the time, “only sense”). Only by chance about a month later did I discover this. Luckily I was pretty much the only dope on this site who had been using the subsections as IDs, at least in large number, so the damage was mostly limited to just me.
So – only use infrageneric taxa if you are quite sure that they will be stable.
I think I found the flag in question – I’m sorry that they came off a little dismissive of your well-researched proposal. I don’t think fretting about whether to employ subgenera vs. sections is a good reason to reject implementation. But I do have more practical concerns about the long-term stability of the proposed infrageneric taxa in this instance – please see the flag.
I think we need better guidance on when flags should be used; it seems clear to me in this case that the curator should have flagged the genus first and gotten assent from at least one other relevant identifier/curator before going through with this, but I don’t think there’s anything in the Curator Guide that advises doing that.
Yeah, I mean, this was a “repeat-offender” who I have seen get chewed-out enough at this point for similarly reckless curation in an even larger genus. But this was all done in good faith. These were just careless lapses, I guess.
I feel like it should go without saying that a curator should always at least “@-notify” the people affected by any change of this magnitude. I’m not sure there is much overlap between “curators who care so little about the IDs of others that they make giant, disruptive changes without notification” and “curators who actually read the Curator Guide”. But maybe it would be helpful.
I can speak to my focus in beetles about this subject. My specialty is donaciine beetles, a popular group and fairly well represented in iNat obs. I created some subgeneric classification in iNat for this group because doing so would help to refine many obs that would otherwise get stuck at genus. HOWEVER, the subgenera were existing in the published literature aready, AND made sense to me as a taxonomist. If I were to attempt to publish any new subgeneric categories in the subfamily in a refereed journal, the manuscript would be rejected, unless I provided a stunning volume of hard data such as DNA, host plant relations, etc., in the context of a comprehensive taxonomic monograph of the subfamily. That rigorous a treatment cannot and should not be the subject of iNaturalist curation. At least in the Zoology part, the ICZN rules governing the nomenclature of animals wouldn’t recognize those created in iNat. So, general Users and Curators in iNaturalist should focus on finding the existing literature, if there is really a need, and see if there’s already a classification that makes sense but hasn’t yet been applied in iNaturalist. But that could be a daunting task, I suspect.