The discussion below is focused on plants and POWO, but I believe similar issues must exist in other parts of the taxonomic tree. I’ve run into a few situations recently where new taxa have been described within genera that iNat (based on POWO) regards as junior synonyms for other genera.
For example, POWO treats the genus Behria as a synonym for Bessera and the genus Ainea as a synonym for Tigridia. There are arguments about whether these pairs of genera are separate or synonymous, but that’s not my concern here. I’m generally fine with iNat choosing POWO’s taxonomy. However, when new taxa are then described within the disfavored genera, POWO has no real place to put them.
The most recent example is the description this month of Behria leonis, segregated from Behria tenuiflora. There’s no reason to dispute that B. leonis is a distinct species, but my understanding is that POWO would regard this as an “unplaced name” because “it cannot be put into synonymy, … because no correct name is available in an accepted genus”.
You might think that the issue here is that we just need to wait for POWO to review the new publication and decide how to treat the new name. So, let’s take a slightly older example. A new variety of Ainea conzattii was published in June 2023. [Full disclosure: I’m an author on that article, but was not responsible for the decision to place this within Ainea rather than Tigridia.] POWO already regarded the genus Ainea as a junior synonym for Tigridia. POWO appears to have now reviewed the article and is treating the new variety as a synonym for T. conzattii. I’m almost certain that POWO’s decision is based just on the authors following a different taxonomy from POWO and therefore there being no name in Tigridia to apply to the new variety. I don’t think POWO is taking the position that A. conzattii var. macropetala is synonymous with A. conzattii var. conzattii
Of course, one way for iNat to resolve these “unplaced names” could be to wait until someone publishes an article transferring the name to a genus that POWO accepts (and in fact that did just happen for Tigridia conzattii var. macropetala, so I’ll take that up with POWO). However, it seem likely that some validly described taxa won’t get alternative, POWO-accepted names any time soon. In some cases, all the researchers working on these organisms in the field use a taxonomy not accepted by POWO. So no one that knows these species is going to be motivated to publish articles transferring the new species to the genera that POWO accepts.
One possible approach here could be for iNat to add a new taxon under the valid name it was published with, and place that under the correct parent (with a conflicting name). So Behria leonis could be added a species-level iNat taxon under Bessera. And prior to its transfer, Ainea conzattii var. macropetala could have been added as a variety-level iNat taxon under Tigridia conzattii.
Some examples like this exist already, but I’m not sure that they were specifically created to address this issue of unplaced names, and I won’t dispute that they’re “ugly”. Is there a better approach to address this? I don’t like the idea of ignoring the existence of these new taxa indefinitely. It seems preferable to have some name we can correctly apply to iNat observations, even if we later update the name with a taxon change.