I wanted to try to feel out people’s opinions on what common names are, at their core. There seem to be two interpretations that I see commonly on iNaturalist. The first interpretation is that they are just whatever names people use for taxa (one might term this “descriptive”). The second interpretation is that they are specific non-scientific names decided upon by experts (one might term this “prescriptive”). In the first interpretation, any source for a common name should do, and common names might be a bit plastic on our end. In the second, common names are more rigid on our end and should only be sourced from specific compiled lists; they are also subject to being changed by experts if taxonomic opinions change. I bring up this topic since I have seen a few flags about common names which are clearly in use online, calling for their removal only because they are not found in field guides or scientific publications, and this has got me thinking about my interactions with them on iNaturalist and elsewhere. I am curious if there is a consensus about what to do in these cases, as well.
What follows next will be my opinion on the topic.
I understand and agree with the need to have some selectivity with regards to common name use on iNaturalist. Good examples of undesirable names, I think, are names which contain possibly offensive terms (i.e. “Indian,” “Confederate”), names which are in common use for multiple taxa in different areas, and names which are clearly 100% fabricated by a user adding them to a taxon (not in use anywhere else, and not related to other common names in use).
This said, I would describe my interpretation of common names as interpretation one above, that as long as a group of people are using them somewhere, then they should be fine. I do not really see the point of regulating them like we do scientific names.
My understanding of scientific names is that they are artificial constructs whose primary function is to allow people to unambiguously (I know this is often not true) talk about a particular organism. They do not belong to any language, but are rather overlaid on every language, so that regardless of what language you speak, it can be clear what organism you are referring to (I know in practice this is fairly western-centric, as they do use a particular alphabet and primarily a pair of languages from southern Europe). Additionally, scientific names are regulated by the various nomenclatural codes in place, which indicate ways in which one could change names, and which names are preferred among homonyms, synonyms, etc. (I assume; I am only familiar with the ICN, which does do these things).
If we try to regulate common names in the same or a similar way, as far as I can tell, we are just creating multiple parallel, worse nomenclatural systems. In the case of common names, a single set for the world cannot do; there has to be a different set for each language, and it is impossible to talk between languages with them in many cases. Common names are also not formally regulated in any way; you have to just rely on a consensus among experts that might not exist (and not just for taxonomic reasons, which would be an issue in any case). Common names don’t exist for every organism; this is true for scientific names as well, but I would hazard a guess that more organisms have scientific names than common names. It also just feels like a waste of effort; we already have scientific names that do these things as well or better.
It also seems to me that, unlike scientific names which take into account taxonomy, common names coined by experts in books or publications are not inherently better than common names coined by people online. They can be equally random and arbitrary, or invented with a motivation in the same way. Two examples come to mind that I am particularly aware of. The Audubon Field Guide to Mushrooms contains almost entirely common names coined by the author and often little used elsewhere; sometimes the taxa already had more accepted common names. Another example is the name “Beach Broccoli” for Cladonia submitis , which has appeared (as far as I can tell) solely in a handful of sources (including a peer-reviewed article https://doi.org/10.1007/s10531-020-01983-x) where two or three people refer to it as that. I am not saying that these names should not be used, only that they are not less arbitrary than someone online making up a name that ultimately a group of people start using. One could make an argument for accessibility with regards to common field guides, but in an era where so much information is online, I would argue that scientific publications and books are less accessible, not more.
I also alluded earlier to thinking about my interactions with common names, and an issue of plasticity and rigidity on our end. I personally try not to use common names at all, and prefer scientific names; I set my account to show scientific names first and common names in parentheses a long time ago. I do try to be helpful with them, especially with fungal taxa on iNaturalist. Unfortunately, many common names in use predate molecular work and the extensive taxonomic changes in Mycology over the last few decades. As such, a lot of these “expert names” are useless, as they refer to multiple taxa spread through Europe and North America (usually), and often people do not bother to coin new common names as the taxonomy changes. People in both places still use the name, though. In that case, should both be deleted? Should they be changed so that one says “European” and the other “American,” even if these names are not used in practice? Should the group containing all of these just be given the common name (perhaps pluralized), even if locally, it is only applied to a single species? To my mind, the second and third should be acceptable, even if they are technically “inventing new names,” as the alternatives of deleting all instances of the name, leaving all instances of the name, or leaving the name for only a particular taxon have greater potential for confusion.