Flag for Taxon: great stinging nettle (Urtica dioica)
| Flagger | Content Author | Content | Reason | Flag Created | Resolved by | Resolution |
|---|---|---|---|---|---|---|
| bouteloua | great stinging nettle (Urtica dioica) |
needs to be split |
Jan. 16, 2022 14:45:34 +0000 | Not Resolved |
Comments
I can't find any other species that have been split out of U. diocia by powo.
U. gracilis is valid in POWO and has been a taxon on iNat for some time; I've committed the swap of ssp. gracilis over to it.
Two iNat taxa for 1 taxon should never exist at any point on iNat. It's not an intentional thing that occurs, I would guess such stems from auto-imported taxa.
The split would also need to be committed at the same time. this would affect tens of thousands of observations, so should probably be committed by staff at a time that makes sense for the website. @loarie?
If sources other than POWO are considered, Urtica in Alaska is treated differently in the 2020 Flora of Alaska project, https://floraofalaska.org/provisional-checklist/. It recognizes U. dioica sondenii and U. gracilis for reasons mentioned in Panarctic Flora, http://panarcticflora.org/results?biogeographic=&bioclimatic=®ion=&name=Urtica%20gracilis#paf-660102.
Thanks for your work on iNat!
Dennis Ronsse
@dennisronsse I believe that treatment would concord with POWO. POWO currently accepts U. dioca ssp. sondenii and U. gracilis.
But that raises another issue of duplicated taxa. Both U. dioca sondenii and U. sondenii exist on iNat.
EDIT: looks like the swap for that has already been drafted. https://www.inaturalist.org/taxon_changes/102379
Thanks @paulexcoff, I see what you are saying. POWO accepts U. dioica sondenii, and mentions, "This subspecies is accepted, and its native range is N. & E. Europe to Mongolia." Flora of AK authors state reasons why that name applies to some AK plants as well, which is not a problem of iNat. Good luck on the other little mess.
Someone renamed U dioica to "European stinging nettle" - that seems rather premature, until the taxon swap actually happens, since all our North American native nettles are now called "European".
Yes, everything should be prepared now for the split, it just needs to be committed.
That split will roll every New World observation of Urtica dioica back to Urtica. Is that what's intended?
Do you have any estimates on what proportion of the IDs/obs of Urtica dioica (sensu lato) would be ultimately considered Urtica dioica (sensu stricto) and what proportion would be considered U. gracilis?
Urtica dioica is in our top 65 species in terms of number of observations so this split would be really disruptive. Lets wait until after the Spring bump we're currently experiencing.
No idea on proportions continent-wide unfortunately. But yeah, I'd recommend bumping them all back to genus due to most people I know IDing these as "sensu lato" for many years. Flora of the Chicago Region actually states "Urtica dioica ... has been reported for the region... but we have found no substantiating specimens" - so there are ~300 obs that might not be U. dioica sensu stricto here. And Calflora still lumps the native one under a U. dioica sensu lato, with only 23 datapoints listed under U. dioica subsp. dioica and 185 under U. dioica subsp. graiclis, so there are ~3500 obs that may or may not be U. dioica sensu stricto there.
Weakley shows U. dioica sensu stricto occurring in most of the southeast, mostly overlapping with U. gracilis. Maybe someone has a very good handle on true U. dioica sensu stricto's distribution in North America to help with more refined atlasing, but I haven't found anything super detailed in my brief research, and it may be that their distributions overlap almost everywhere anyway.
I updated the atlases per VASCAN, assuming they are correct, which would move 1132 obs of U. dioica to U. gracilis.
What's happening to holoserica? Both (fka) U. dioica gracilis and U. dioica holoserica grow in the Bay Area (1100 across CA in Calflora) but most on iNat don't take them to ssp. which I imagine would further complicate matters.
Those taxa were already moved to U. gracilis (recently). But yeah exactly, since most people don't ID to subspecies, Urtica dioica (species rank) needs to be split as well.
@loarie would that be ~week of May 10th?
Unfortunately I agree it would be best to bump everything back to genus-level, but with 19,000 observations of U. dioica in North America it would heavily obscure observations of other Urtica sp.
How about creating a U. dioica complex containing both species, then bumping all observations in the Americas back to that instead?
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Another reference regarding NA proportions; BC E-Flora:
ssp. gracilis - common throughout BC; N to AK, YT and NT, E to NF and S to ME, NH, NY, PA, NC, MS, LA, TX, NM, AZ, CA, and MX; S America
ssp. dioica - rare in SW BC; introduced from Europe.
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U. dioica/gracilis subspecies (in POWO) that are currently full species on iNat: U. galeopsifolia (swap draft), U. angustifolia
Does anyone have a decent key for north american nettles under the new taxon scheme? I'd be happy to start working on re-identifying some of those, but I don't want to accidentally introduce more errors.
@cgbc I see several sources saying that the two species aren't even that closely related, so perhaps a complex is not the best solution.
@raymie Any links? Or anything else regarding NA Urtica genetics?
@cgbc I got the "not closely related" claim from Wikipedia, which lists no citation (https://en.wikipedia.org/wiki/Urtica_dioica_subsp._gracilis#:~:text=Urtica%20gracilis%2C%20the%20California%20nettle,closely%20related%20to%20Urtica%20dioica.).
I did find this 1982 paper on North American Urtica which may be of interest, despite its age: https://www.jstor.org/stable/2418389
i would encourage you all not to make this change, but if you do, please don't bump all in north america back to genus and please remove the 'european stinging nettle' name from dioica until you make that change (assuming that's even a valid name). Or at least, use a complex or something. This cahsing of genetics to make constant changing has real-life consequences and no clear benefits really, especially when spatially differentiated. Anyone who likes the new change can assume dioica in north america is their new species.
Yes, the "European" Stinging Nettle name is already causing a lot of identification confusion, and could be causing people to assume their plants are non-native and should be killed.
@loarie - ready to commit? https://www.inaturalist.org/taxon_changes/109956
Is there a place the iNat policy on splitting and taxonomy chasing is laid out? I don't agree with all the taxonomy cahsing but maybe if the rule was clear i'd be able to stop fussing over it and just accept it for what it is. I feel like a few years ago the plan was to only use set secondary sources but now any time a new paper comes out everyone completely changes taxonomy and it makes it a nightmare for things like cross referencing to my species database i use at work. I don't want to ask on the forum because i will get roped into arguing over taxonomy and its bad for my mental health
shooting you a message
Thank you!
When is this getting committed?
I now see that the split already happened on 4/23/22, but, if I understand the terminology correctly, the identifications were never re-assigned to the output taxa based on their atlases, as the language in the split said would happen when the split was committed.. I presume this would re-assign all previous North American observations marked "Urtica dioica" to "U. gracilis". Why didn't that happen?
@stewartwechsler - Where are you seeing that the "split already happened"? It has not been committed yet.
@ddennism We already have a page for U. gracilis, as a full species. It had been treated as a race of U. dioica, U. dioica ssp. gracilis, and I presume it couldn't be a full species until U. dioica was split into U. gracilis and U. dioica. I had presumed that when U. dioica gracilis was replaced with U. gracilis gracilis on 2022-04-23 that was effectively a split:
https://www.inaturalist.org/taxon_changes/75501
No, I'm afraid you're mistaken. The relevant (drafted, not committed)split is here (https://www.inaturalist.org/taxon_changes/109956), but I can definitely see why seeing a preexisting U. gracilis entity would be confusing. Hopefully the split will be committed soon.
Looks like committing this will keep 111,228 of the 153,667 IDs at Urtica dioica, replace 1,339 with Urtica gracilis and 1,283+39,817 with Urtica is this whats intended? If so I think its ready to commit
Total IDs of input taxon: 153667
Number of IDs Destination Atlas
111228 Urtica dioica Atlased
1339 Urtica gracilis Atlased
1283 Urtica Outside of all atlases
39817 Urtica Overlapping atlases
Is it possible to review and comment on the atlas. I have been surveying the western North American Urtica with the intent to understand ssp. gracilis and ssp. holosericea. The take away is that the POWO distribution maps provide a reasonable outline of U. gracilis that the ssp. outlines are confusing. It appears that the two subspecies occupy different areas with limited sympatric occurrence and some level of introgression. Thus ssp. holosericea is a taxon of the dry intermountain region and most of California with ssp. gracilis as mostly a northern and mountain taxon. iNaturalist observations bare out the Jepson mapping of ssp. gracilis as costal in California. There appears to be introgression in the intermountain region in British Columbia and central Washington State. The third area of sympatric overlap with introgression is the Rio Grand region of New Mexico. This limited view of the overall North American taxa is only addressing the of the U. g. subspecies.
A second note is on the current count of U. gracilis observations. The taxon ssp. gracilis has 934 identified observations. There are addational numbers with duel U. dioica and U. gracilis ssp. gracilis identifications. These observations are at a "needs id" condition. A systematic update on the U. dioica id would bring the observation to research grade. The same state of id is present for U. dioica and U. g. ssp. holosericea. I note this as the above comments speak to the current number of U. gracilis observations.
It appears that the very active botanist teams at Jepson, Oregon Flora, and Burke Herbarium have all looked at this and decided to keep gracilis at the subspecies level. These are not botanists averse to either splitting or to change. I believe they decided this on its merits. Just because a revision gets published doesn't mean that botanists will generally accept it 10 or 20 years from now.
Interestingly, just earlier today I checked on the status of U. dioica / gracilis at the University of Washington's Burke Herbarium, Oregon Flora (University of Oregon), and eFlora BC (University of British Columbia), all of them still using "U. dioica" for the local species we mostly see here. Now, when I mark a local iNaturalist observation "U. gracilis" rather than "U. dioica", I do it so that it doesn't get marked by iNaturalist as "Introduced", and then explain that, it is iNaturalist's taxonomy that has marked our native material "U. gracilis", and has marked "U. dioica" as a Eurasian species that is not native in North America (except one endemic Alaskan race of "U. dioica"). I don't actually have much opinion of whether a North American species should be split from the Eurasian species. My main concern has been that our native material not be called "introduced". When I now look at the iNaturalist map of "U. dioica" North America is covered with a density of observations marked "U. dioica", but I am reasonably confident that few of them are the non-native taxon that has long been treated as "U. dioica ssp. dioica", as there are few records in the Consortium of Pacific Northwest Herbaria (CPNWH) under "C. dioica dioica" (CPNWH also still treating our native as "C. dioica")
"Just because a revision gets published doesn't mean that botanists will generally accept it 10 or 20 years from now."
they very often don't but inaturalist's policy literally seems to be accept any split that has any possible link to a publication (even non peer reviewed!). I get why people love the novel, but i really really really wish we'd go back to the secondary sources approach. It's started affecting my ability to use the site for work very heavily, which is the main reason i post less observations now :(
This change caused mass chaos and was completely avoidable just by using subspecies level instead.
@charlie iNat's policy on plant taxonomy is just to follow whatever POWO says. If you would like to dispute this split, contact POWO.
well if POWO has become so extreme maybe iNat should take a second look at whether to follow it.
And that is all i will say about this in here because i don't like being yelled at. I've got my unpopular taxonomic opinions here if anyone is interested, and will leave it out of this comment thread otherwise. https://www.inaturalist.org/journal/charlie/68030-my-take-on-taxonomy
Has anyone in the "keep gracilis a sub-specific entity" camp bothered to write to POWO about this yet?
If you send them a well-sourced (but brief!) paragraph or two, they'll often incorporate it into their taxonomic decisions, even if it's just in the form of additional citations in the "not followed by" section. They strike me as smart people who are seeking to represent scientific consensus, rather than "extremists" as characterized above.
This would be much more productive than posting manifestos.
The reason we punt most taxonomic decisions like these to bodies like POWO is to avoid having to make so many lump/split judgement calls ourselves. Especially in cases that are ultimately a matter of rank, which can range into the somewhat arbitrary.
Echoing what @ddennism wrote - POWO is actively engaged in maintaining a global plant taxonomy with broad buy in, makes weekly changes, and is grappling with all these questions about how to make compromises etc, so we don't need to reinvent the wheel here. I'm looping in @thebeachcomber who has been having a (I believe) productive exchange with the POWO folks about some changes to Eucalyptus in case they have tips for working with POWO. The email is bi@kew.org
@ddennism Well, i definitely don't have the time or energy to try to lobby POWO to change their policies, i don't think a group like that would listen given even in this generalist naturalist group it's a pretty maverick opinion. and anyhow it wouldn't solve the issue for non plant taxa. The 'manifesto' is an attempt to stop myself from spreading the same concern everywhere, so it's all in one place and people who want to can discuss it off thread. But maybe even that link is starting to annoy people. Conversely if you want to send the 'manifesto' to POWO i certainly support that, but i doubt it would make a difference. I think the science of ecology is heading for a bad time with this stuff, but ultimately, there isn't much more i can do about it realistically as all i am accomplishing is irritating the taxonomists and getting others to message me that they agree but they too are afraid to talk about it publicly or don't want to get attacked. People are just gonna do what they are gonna do. I need to let it go.
in all my interactions with POWO (Rafael), they have been great; either they accept my proposed changes and implement them as quick as they can, or they provide good explanations for keeping the status quo
@charlie - Oh I wasn't clear - I'm suggesting a very quick correspondence outlining the specific reasons you think they're in the wrong in this particular case: species-level recognition of U. gracilis. I'd do it myself, but frankly, the last time I looked into this I remember being personally swayed that species-level status makes the most sense.
I like most of your manifesto, btw! I agree that pumping the brakes on taxonomy changes, adopting them only with caution and deliberation, is the way to go. That's kinda why we appeal to third party authorities like POWO with a global scope. They can exercise expert caution and deliberation, probably better than iNaturalist can. If you think they're in error - do what scientists do - show them the evidence!
Thanks! Yeah i am trying not to bury this thread in my stuff, but i'm not saying the people at POWO aren't good scientists or good people, i just guess at this point i broadly disagree with how taxonomy is done across the board. Or something
Is there any reason this split hasn't been committed yet?
The costs of this split far outweigh the benefits, so it just shouldn't be done! That is even if this would be the one case where iNaturalist doesn't follow POWO taxonomy! (Or is iNaturalist just an arm of POWO?!) If all of the 23,900+ Urtica dioica observations in North America, that don't already go to subspecies, will be changed to "Urtica", these observations won't be distinguishable from the other 15 Urtica species being recorded in North America. It is really an arbitrary taxonomic decision whether or not "U. dioica ssp. gracilis" should just be "U. gracilis". They are the same taxon either way, but the taxonomy change comes at a great cost!
We already have all of the iNaturalist "Urtica dioica" observations in North America given a red asterisk claiming that those plants are not native, and an unknown number of people have since been pulling out these plants because they thought they were invasive species, while 99% of those plants are indeed native. My greatest concern is that the native Stinging Nettle - Uritica dioica senso lato is a critical part of local ecosystems around North America, and the exclusive host plant for 3 of our Pacific Northwest North American butterflies (that is their caterpillars only feed on U. dioica), and possibly for more butterflies in the rest of North America. It is also an alternate host plant for 2 more of our Pacific Northwest butterflies, and I think other North American butterflies, not to mention the countless other taxa that depend on our native Stinging Nettles that are harmed by people pulling them out.
We also need to put "Urtica gracilis" back to "U. dioica ssp. gracilis", or potentially to "U. dioica", both to be consistent, and as most of the "U. gracilis" ID's were made based on the plants being in North America, not based on people following a key that distinguished their "Urtica" as "gracilis". This taxonomy would agree with that of a high percentage of North American universities.
(My longer, earlier Journal post on the subject)
iNat is not "an arm of POWO" (whatever that means), but we should be following it. We don't make our own taxonomy here.
iNaturalist is also not "an arm of raymie" so your opinion on POWO isn't the only one that matter here. There's no law that we ought to follow POWO, that's just what some people want to do.
If Urtica dioica is native in North America, why is it marked as introduced?
because POWO decided to change the name of the Urtica species such that dioica only replies to one native somewhere else
@charlie It's also not an arm of charlie. We are supposed to be following POWO. A "small amount" of deviations are allowed (a mistake IMO but that's irrelevant here). This is not a deviation, as both taxa are in iNat already, and @loarie did express intent to split the taxon above. I think we can all agree that how this is being handled right now is a problem. Either we split this or we decide we're deviating. We can't let this sit around as is like we have been doing for the past two years.
we are 'supposed' to follow POWO in terms of the iNat community and admins deciding that we are supposed to. That's as far as it goes. If POWO moves into taxonomy that's unusable on iNat why would we keep using it? iNat will have to adapt and change in response to whatever happens in the scientific community including the aggressive splitting now occurring.
"Unusable on iNat" is subjective.
But regardless, the way this is being handled with this taxon atm is a problem, and we should just be coming up with a solution to it and not let this sit around and cause more problems. IMO, splitting this is the far easier way, but we could also lump U. gracilis.
yes but your opinion is literally always 'splitting is the far easier way' and others are saying that isn't working for them, broadly, and also with this taxa.
@charlie And your opinion is always maintaining status quo is easier and others are saying that isn't working for them, broadly.
my opinion is definitely not maintaining the status quo, it's that we need to reduce the rate of taxonomic change and especially splitting, as pertains to a citizen science website where most people are harmed by the new taxonomy, or else somehow create parallel taxonomies so the splitters and revisionists don't break iNat for everyone else. That's not status quo at all, the splitters have been the status quo here for several years alraedy.
But yes we need balance and no i don't expect i'd get what i think is best all the time, of course.
@raymie what is the issue it causes you to keep the splits at subspecies? Just that it bothers you that it doesn't match POWO? Is there actual harm done by doing that?
My understanding is there's 2 issues here that are being mixed. One is how to best bring IDs in line with the taxonomy (e.g. should.Urtica dioica be retroactively split into Urtica dioica and Urtica gracilis) and the other is whether we should deviate from POWO by having Urtica dioica senus lato or stick with Urtica dioica stricto and Urtica gracilis
@raymie - you're correct that because both Urtica dioica and Urtica gracilis are active taxa on iNat, we should interpret Urtica dioica as sensu stricto and ID accordingly. But its not always necessary to retroactively split a taxon. It depends on whether it would be more or less disruptive/confusing to commit a split or just sort it out through IDs -see here https://help.inaturalist.org/en/support/solutions/articles/151000015337-section-d-how-to-respond-to-a-flag-requesting-to-split-a-taxon I haven't looked into this deeply enough to weigh in on whether a split is the lesser of 2 disruptions for getting IDs in line with Urtica dioica sensu stricto and Urtica gracilis. There's no right answer here, just guidelines.
I also agree with you that if the intention is to deviate from POWO and go with Urtica dioica sensu lato we should merge Urtica gracilis -> Urtica dioica to make this clear. Like you, I'd prefer to minimize deviations from POWO, but its perfectly fine to deviate and again there's no correct answer.
If we choose to split as POWO does, the we need to commit to a taxon swap. Currently, the vast majority of observations in North America are showing as U. dioica when they are in fact U. gracilis.
@charlie While we're talking like that, my opinion isn't "splitting is the far easier way", it's "following POWO is the far easier way".
kinda one and the same with how POWO has gone though
@charlie Well your philosophy seems to be one and the same with maintaining the status quo.
that just shows you don't understand it and haven't been listening, so i guess as with other flags, talking to you about it and trying to explain isn't worth any more time.
I agree with raymie in that I expect a vast majority of Stinging Nettle observations in North America are probably gracilis, which would be "Urtica dioica gracilis" if you have the taxa lumped, or "U. gracilis" if you have the taxon split. That iNaturalist has been labeling observations of this critically important native taxon as an introduced species for 2 years is why I, as someone who has made the protection of native plant species a central focus, with an extra focus on butterfly host plants, am particularly upset that iNaturalist has been giving everyone encouragement to eradicate our Stinging Nettles as an invasive species. In contrast, I am planting the species for the butterflies, and teaching others to do the same! I also agree with raymie that if we don't split U. dioica we should lump U. gracilis.
I agree with @stewartwechsler - the biggest issue right now is that people are killing a native species because they believe it to be invasive. I have had to personally educate multiple people about the issue, so there are surely far more who don't know.
I'm in favor of following POWO personally, but I really don't care how the taxonomy settles out as long as it stops encouraging people to destroy native ecosystems!
If you want to follow POWO on this taxonomy, you could change all North American observations of "U. dioica", that don't specify subspecies, to U. gracilis, then only treat U. dioica ssp. dioica, and U. dioica ssp. sondenii, as not native in North America. If people ID something in North America as "U. dioica" it is most likely what you are calling "U. gracilis", and has been long been called "U. dioica ssp. gracilis", so it shouldn't be called "not native" until someone specifies subspecies dioica.
I'm going to set aside taxonomy for a minute... is U. diotica senso stricto actually ever invasive in North America? If it's not a big issue i propose we remove the 'non native' tag from that species regardless of the taxonomy until we get it all sorted. Even if it gets changed to gracillis we are going to have years of people identifying it as diotica based on field guides and older references, and thinking it is invasive. I think in this case the invasive tag is best removed.
I think changing its establishment status would be the most beneficial thing to do at this moment.
@charlie Part of this is just unnecessary stigma around introduced species. Just because something is introduced doesn't mean it's bad.
well i don't disagree with you on that one @raymie. I think the data robustly indicates that invasive species are harmful, but i don't think all introduced species are invasive, and going and yanking introduced plants from every place they are encountered isn't necessarily the correct choice. I've never heard of the european subspecies (or whatever) of nettle being invasive in north america.
For me the issue isn't whether or not U. dioica ssp. dioica is truly "invasive", but that many people equate "non-native" with "invasive", and many people think non-native species should be removed, and do remove them when they can. This means that the red asterisk of "not native" means that other people will be removing Stinging Nettle if they think it is non-native, but most of the plants that have been called "Urtica dioica", and many of those that will be called "Urtica dioica" in the future, will actually be the native taxon that could be called "Urtica gracilis" or "Urtica dioica gracilis".
Satyr comma butterflies rely on U. dioca sensu lato as a host plant.
@loarie Would it be difficult to adjust the software that flags non-native species so it doesn't flag "U. dioica" as non-native? And/or drop the " Introduced in United States" banner? I see that you (or someone else) has already changed the American name to Great Stinging Nettle, omitting any mention of Europe. Thanks for being the peacemaker.
I haven't been closely following this thread. but if I'm understanding correctly, IMO the priority should be reaching a decision about:
follow POWO with U. dioica sensu stricto native to Europe and U. gracilis native to the Americas.
deviate from POWO with U. dioica sensu lato native to both the Europe and the Americas
If we want to go with 1, we should probably commit the split which will roll many America Urtica back to genus
If we want to go with 2, we should probably swap U. gracilis into U. dioica
Again, I'm not following this closely, but if we're following U. dioica sensu lato I would think the establishment means for the Americas should be native and if we're following U. dioica sensu stricto the establishment means for the Americas should be non-native.
If a decision can't be reached, my preference is to defer to POWO since they're focused on maintaining a global plant taxonomy and have processes in place for decision making that we can defer to. But if there is a decision reached here that's great. I don't have a preference either way re: sensu lato or sensu stricto.
Whatever happens we should get it in before the taxon change pause for the CNC.
When does that happen? I've been putting off a few chironomid tweaks and additions.
April 24-May 6
Thank you.
We should go ahead with the split. It's been about a decade since the molecular phylogeny showing the phylogenetic distinctiveness of U. gracilis was published. The authors of that study noted that their conclusions were in broad agreement with the morphological distinctions emphasized in the early 1980s by Dennis Woodland. I cannot find a perspective that outright disagrees with this phylogeny from the intervening nine years. I can only find some checklists, floras, and popular works that either ignore it, or are apparently unaware of it. People have had over forty years to mount a counter-argument, but one has not been forthcoming. This is not "taxonomy chasing".
Swapping U. gracilis into U. dioica will make a very strange "sensu iNat and iNat only" U. dioica that will artificially exclude some South/Central American, Australasian, African, and Asian taxa from the concept while including a less-related North American taxon. iNat needs to have a global perspective.
It's a shame that so many "U. dioica" IDs in the western hemisphere will be bumped up to genus-level, instead of being transferred to U. gracilis. I feel like anyone trying to say "I think this is actually the nonnative, bushier, hairier, larger-toothed, stingy-er, mostly-dioecious U. dioica" has already done so by using "U. dioica ssp. dioica" as an ID. Do we really have to bump everything up to genus?
you could set up the atlases in a nonoverlapping way (e.g. such that U. gracilis only occurs in the Americas and U. dioica only occurs in the old world) which will replace all America IDs of U. dioica with U. gracilis. That will probably upset some people/make a mess by changing IDs intended to be U. dioica sensu stricto to U. gracilis. But it might upset less people than rolling all America U. dioica back to Urtica.
Yes. I think this is the question. My vote is to bump up to genus, anyway. In my experience with other splits like this, people get very mad (and understandably so!) when an ID moves from one intended-to-be-specific ID to another, rather than from specific to general.
I wish we could invoke a "dioica complex" but it seems like that concept is kinda already in use in Eurasia for U. dioica s.s. and its much closer relatives.
We already have 69 observations of "Urtica dioica dioica" in North America. I would say these are clearly intended as the dioecious European taxon. There is no need to change these in any taxon swap. It is also my understanding from examining the Consortium of Pacific Northwest Herbaria (CPNWH) records, in my part of the country / continent, that I know best, that there are few (25) records in the Pacific Northwest of North America for the dioicious, European taxon. While the European, dioicious taxon has been recorded in the Pacific Northwest and elsewhere in North America, it does not appear to be among alien, invasive species that have widely spread in North America.
Whatever we do, many iNaturalist users, that either haven't learned the newer taxonomy, or who are following older references or other authorities, such as local herbaria, that so far haven't accepted the newer taxonomy, will continue to know our our native Stinging Nettles as "Urtica dioica", and label their new observations as such. My concern is that people are hearing that the Stinging Nettle that they know as "Urtica dioica" is a non-native, invasive species ("non-native" widely equated with "invasive") which those managing land for native species should remove. As someone focusing on managing land for native species that our native butterflies use, and with Stinging Nettle - Urtica dioica senso lato at the top of the list of our butterfly host plants, this is of particular concern to me. In the Pacific Northwest alone, there are 5 butterfly species that host on (lay eggs on) Stinging Nettle - Urtica dioica senso lato, 3 of these are obligate on Urtica dioica senso lato. Other butterfly species, elsewhere in North America also host on Stinging Nettle - Urtica dioica senso lato. I'm sure there are also non-butterfly species in North America that depend on Stinging Nettles - Urtica dioica senso lato. People removing Stinging Nettles would harm all of these butterfly species, and additional non-butterfly species.
I would suggest we follow the POWO taxonomy here (and having read the supporting paper, I now see this split makes sense), but just leave out an indication of nativity for "Urtica dioica" in North America. This would protect the Stinging Nettles in North America from being labelled "not-native" by iNaturalist, especially as most of those labeled "Urtica dioica" in North America would really be Urtica gracilis by the newer taxonomy. We would then use the North American atlas to transfer all "Urtica dioica" observations to "Urtica gracilis", except those observations labeled "Urtica dioica ssp. dioica", which would not change. Ssp. holosericea (and another ssp.?) were lumped under Urtica gracilis under the proposed taxonomy change, and these would go to subspecies of U. gracilis in this iNaturalist taxon change. I think bumping all iNaturalist "Urtica dioica" observations to "Urtica" would end up losing a lot of valuable data on the distribution of this critically important species in natural communities. If that bumping to genus also took all Eurasian observations of "Urtica dioica" to "Urtica", I will add that I know of 3 European butterfly species that depend on Stinging Nettle - Urtica dioica, and that people also need to know the distribution of that species in Europe. There are other Urtica species that these observations then couldn't be distinguished from.
@stewartwechsler is absolutely correct on the importance of the native Urtica to butterfly conservation and misguided public impressions. Thus, how this split is managed, the management of our native ecological system should be a prime consideration.
Agree with @stewartwechsler's impeccably argued points. I'm somewhat new to iNat and don't grasp the resistance to rolling all North American U. dioica (without ssp.) observations into U. gracilis, when hundreds of other species have undergone "taxon swaps." Are those done only in cases where the swapped-out taxon is no longer accepted at all?
if you care about conservation and public impressions rather than 'conforming to POWO' then you can't really support the split. Lumping to genus seems like an awful idea. Well, you all know my 'vote' (i know i dont' get an actual vote). Maybe we can just make city nature challenge last half the year so we at least get some break from this stuff.
The hundreds of swaps ARE the problem. It's made the site unusable for a lot of things, unfortunately, and it's only accelerating because some contingents really want to make inaturalist 'match POWO'
We should get whatever taxon swap we're doing in in the next few hours to minimize the confusing the current status would cause during the CNC.
@raymie Could you tell us what CNC is?
@stewartwechsler The City Nature Challenge. The period of the highest iNat usage, and it starts tomorrow. Taxon swaps are paused during that period because the site cannot handle them on top of the high usage.
@raymie Thank you.
goes to show how we really can't handle all these constant swaps at all, it just causes less damage during less busy times, it still has a major impact.
So it seems like everyone has decided on splitting, what are preferences to bumping all back to genus vs swapping them all (minus the ones IDed as U. d. dioica) to U. gracilis? We should really do this ASAP.
While I suggested Urtica dioica be split, it could be an exaggeration to say I decided on it. In reality I don't so much want the split, as I want any split to be managed to best protect native ecological systems, and to protect useful records of "Urtica dioica" senso lato from being bumped back to "Urtica". (This would be unlike the labeling of "Urtica dioica" as "not native in North America" 2 years ago, but before any split was technically done.) I have to agree with @charlie that we really have have too many splits at too great a rate, and that the following of POWO on all of their taxonomic changes every time a new paper only proposes a new split, is the biggest part of the problem. Stability of taxon names is why Linneaus created the scientific naming system we now use, but it often seems that the common names have now almost become more stable than the scientific names, which is half of why I chose to include "Stinging Nettle" in my comments above.
I agree that the solving the issue of that status of this taxon is super important for its conservation, and either taxonomic scheme can solve that problem. Damage has already been done, and it should be fixed before the CNC starts in less than 24 hours. Since comments are overwhemingly in favor of splitting (with just one user continusly objecting) we should do it ASAP. I am not a curator, so someone else will have to do it. We just have to figure out if we're bumping observations back to genus or not.
Ok. I have no strong feelings on changing the name urtica dioicia to urtica graciles or not. However, I do have an opinion on the disruptive nature of the taxon swap as currently proposed.
Here are some numbers:
There are currently 24,802 observations labelled u. diocia in North America. Of these, 14,695 are research grade. There are 10,052 needs-ID urtica observations in North America at genus exactly. Of these, 2,810 are just disagreements between u. diocia and u. graciles, so there are 7,242 urtica that could be a different species. There are 2,314 needs-ID and 4,203 RG North American urtica ID'd to species other than u. diocia or u. graciles. Therefore, in total, there are about 9556 needs ID observations where a different species is possible given current IDs. Therefore, if nearly all current u. diocia IDs were knocked back to genus, the not-actually-uncertain IDs would outnumber the genuinely uncertain IDs 2.5 to 1. This would presumably be a significant burden on IDers trying to filter through the needs ID pool to find the less common species.
For comparison, there are 45 observations RG at u. diocia diocia, 69 observations with a display taxon of u. diocia diocia, and 115 with any ID of u. diocia diocia in North America. Vs 4,073 RG at u. graciles, 6,469 with display taxon u. graciles, and 9,451 which have at least one ID of u. graciles. In other words, less than 0.3% of u. diocia IDs in North America are believed by the community to be actually u. diocia diocia, compared to an overwhelmingly larger number that are certainly u. graciles.
Assuming a typical ID represents approximately 30 seconds of work on the IDers part on average (some less, some much more), and observations have on average 2 IDs, then knocking back all of the urtica diocia IDs in North America costs the site approximately 413 volunteer hours of work (almost $10000 if we were paying IDers California minimum wage; our IDers are probably worth more than minimum wage). We should weight that cost signficantly when doing these kinds of taxon changes.
What if, instead, we just changed the atlas to dump all North American u. diocia IDs into u. graciles (except the ~115 u. diocia diocia IDs, of course)? Anyone who cares to do it could then do an ID blitz to find any handful of those that actually were u. diocia diocia. Such an ID blitz could roughly be estimated to take <1-10% of the IDer time as compared to an ID blitz to refined urtica IDs to urtica graciles, without disrupting IDers who are working on other interesting North American species. If anyone is actually interested in doing this, it would be most efficient if they start right now before any swap is committed. If no one is interested in doing that, to me that says something about how invested the IDer community is in having this swap performed.
On the other hand, a deviation from POWO costs basically nothing, except the time us curators spend arguing about it.
@wildskyflower I like that solution. Swap all U. dioica in North America to U. gracilis except those IDed as U. d. dioica. There will probably be a few misidentification resulting from it but not too many and they can be fixed.
Would you be able to commit to that?
That will work except for obs that have IDs of U. dioica AND U. dioica dioica
e.g. if you set up this split
U. dioica -> U. dioica, U. gracilis
https://www.inaturalist.org/taxon_changes/109956
such that the atlas for U. dioica didn't include any New World places
and the atlas for U. gracilis doesn't include any Old World places
then an obs of with an ID of U. dioica dioica will stay at U. dioica dioica
and an obs with an ID of U. dioica in the US will change to U. gracilis
but an obs with 1 ID of U. dioica and 1 ID of U. dioica dioica will roll back to Urtica (with gracilis clashing with U. dioica dioica)
but if thats tolerable from your perspective then this seems like a good least-harm strategy to me
That sounds fine. I think this should be committed.
@loarie All of this sounds like a least-harm strategy to me, if we would also leave out any indication of nativity for Urtica dioica in North America (or potentially just calling it "native", especially knowing that most future observations of "Urtica dioica" will really be "Urtica gracilis"). This way future observations in North America labeled "Urtica dioica" (as opposed to those labeled "Urtica dioica dioica") by people who will continue using the older taxonomy for an indefinite amount of time, won't get their observations labeled "introduced". There is also a subspecies in Alaska of Urtica dioica ssp. sondenii, that is native there, but may not be affected by the split. This will also prevent those who still know North American Stinging Nettles as "Urtica dioica" from getting the idea that our Stinging Nettles in North America were not native (something I have already heard since iNaturalist labeled Urtica dioica "not native" in North America 2 years ago). Then people managing the land for all natives won't be removing Stinging Nettles, thinking they are alien, and they won't object to planting it. We would still call "Urtica dioica dioica" in North America "not native" / "introduced in North America".
I didn't know about the subspecies in Alaska! Although POWO says it isn't native to Alaska. Either way. Just make sure U. d. sondenii is not also swapped to U. gracilis.
I am not quite sure the subspecies in Alaska is native. I may have been too quick to assume that when I saw no red asterisk indicating an introduced species on an observation of U. dioica sondenii there.
The only source I can find making a claim either way is POWO. It says that U. dioica is introduced in Alaska, but also says subspecies U. d. sondenii is not known from there, so do with that what you will.
Regardless, we should just make sure that the observations of it are not swapped into U. gracilis.
I checked and the vast majority of RG u. dioica dioica observations in North America don't have any plain u. dioca IDs, interestingly enough. The rest can easily be found and outvoted after swap using the ident_taxon_id API key
I feel like for potentially disruptive changes it is valuable to get some thoughts from people who are actually heavy users or observers of these taxa, and only a handful of the existing commenters on this thread are. Here are those lists:
Top IDers of u. gracilis @ajwright @fluffyinca @carexobnupta @jrebman @dustin777 @je9h @plachuff @lallen
Top IDers of North American u. dioica @graysquirrel @animalview29 @alex_iosipenko @popb25 @mangoblatt @mcaple @csledge @leshell @sedgequeen @grnlef
Top IDers of North American u. dioica dioica @seanblaney @wdvanhem @radekwalkowiak @popb25 @rcurtis @iowabiologist
Top observers of u. gracilis @seraphinpoudrier @johndreynolds @marykrieger @rhjackso @eric-schmitty @fmcghee
Top observers of North American u. dioica @iowabiologist @johndreynolds @srall @ken-potter
Top observers of North American u. dioica dioica @dziomber @pwdeacon @michael_oldham @cazort @flosi
Top IDers of North American urtica species other than u. dioica and u. gracilis: @jrebman @graysquirrel @arboretum_amy @grnleaf @matt_g @franpfer @franpfer @hikingsandiego @sambiology
If you are just tuning in and don't want to read the whole thread:
The problem: Our taxonomy reference, POWO, has split u. dioica and u. gracilis into separate species. u. gracilis is the one that is native to North America, and the vast majority of current North American u. dioica IDs are probably u. gracilis in POWO's taxonomy. However there are at least some introduced urtica dioica in North America; we don't know how many, but the current participants on this thread seem to estimate less than 1% overall.
There're are three mutually exclusive proposed solutions to that problem at the moment:
1.) Use curator actions to revert almost all u. dioica IDs in North America to genus, because most of them are probably actually u. gracilis in POWO taxonomy. This will mean they will nearly all have to be re-ID'd by hand, even the ones that are currently Research Grade.
2.) Use curator actions to move almost all u. dioica in North America (except u. dioica dioica) directly to u. gracilis, and then IDers can later move any u. dioica sensu stricto anyone finds back to u. dioica using Identify/standard community ID procedures.
3.) Document a manual deviation from POWO's taxonomy, then use curator actions to move all existing u. gracilis IDs back to a subspecies of u. dioica (u. dioica gracilis). This option requires no intervention from identifiers or observers, but requires us to deviate from our taxonomy reference, which we usually try to avoid.
Any thoughts on these proposals?
I would do 2) in reverse order. Give a few months' grace period to find U. dioica sensu stricto in the dataset and annotate to U. d. subsp. dioica as well as to annotate existing obs of that taxon, then charge onward with the split. Species rank for U. gracilis is being integrated into North American standard references as we speak, so option 3) will make iNat stand out as retrograde.
The two are remarkably easy to tell apart in flower or fruit since the male and female flowers are borne in separate parts of the infl. Ergo, a truly uniform infl (excluding photo and phenology artifacts) = U. dioica s.s., and a two-part infl = monoecious U. gracilis.
If U. dioica s.s. is found widely, it could be that there it gets bumped to genus, but in many places, such as here in Washington, I have so far seen zero evidence of it.
@ajwright We don't want to wait any longer than we already have to minimize confusion about native status about the native North American taxon during the CNC.
@raymie Haste makes waste. The site has survived 8 city nature challenges with the misleading 'introduced' status, 5 of them since the split. It will survive one more.
I just looked into Urtica dioca sondenii and found that iNaturalist has both U. dioica sondenii, and U. sondenii, and has an announcement on U. sondenii that it will be lumped into U. dioica as U. dioica sondenii. I initially only saw the observations under "U. dioica sondenii", with a clustering of 13 observations in Alaska, and 3 observations in Eurasia, and with no red asterisk, indicating it was introduced in Alaska, it looked like an Alaskan native to me. Then seeing the 130 observations under "Urtica sondenii" concentrated in Russian central Asia, and none in Alaska, it seemed more like an Asian species, with an introduced population in Alaska (though no one had entered a note to this effect in "Establishment Means" for Alaska). POWO has U. sondenii as a synonym of U. dioica sondenii.
How to distinguish Urtica dioica dioica ("Urtica dioica" by newer taxonmy) from U. dioica gracilis / Urtica gracilis:
Getting these photographic observations confidently to species may not be so easy.
If people are wanting to distinguish the dioecious European "Urtica dioica dioica" by the older taxonomy, or "Urtica dioica" by the newer taxonomy, from the monoecious native North American "Urtica dioica gracilis" by the older taxonomy, or "Urtica gracilis" by the newer taxonomy, I thought they should know what their male and female flowers look like. Male flowers have 4 spreading stamens - 2nd photo. Female flowers have linear stigmas radiating like a star from each flower - 2nd and 3rd photos. If one plant has only male flowers, or only female flowers, it is dioecious, and the European Urtica dioica ssp. dioica (of course named for being dioecious). If one plant has both male flowers and female flowers (though, being monoecious, the male and female flowers are on separate inflorescences) it is the monoecious American Urtica gracilis (by the newer taxonomy). I question how many observations will make this clear from the photograph set they have, and if an observation only shows one sex of flower on one plant, I wouldn't know whether or not that observation is just lacking a good view of the other sex of flower on that same plant. I expect the species would only seem evident if an observation clearly showed both male and female inflorescences on one plant, which would be U. gracilis. It would be harder to show whether all of the inflorescences on one plant were all of one sex (U. dioica).
I am quite comfortable with continuing to use POWO as our nomenclature reference for Urtica. That comfort is based on the value of the transparency of how we decide which nomenclature source to use and that that nomenclature source chosen is one that is thoughtful, publicly available and has a global scope. To me, exceptions would need to be special to out weigh the benefits of sticking with a single reference.
Atm in Manitoba we only really have one confirmed stinging nettle - which under POWO is U gracilis. Conveniently at the moment this matches VASCANs current take on the matter - but if they didn't I wouldn t mind much. Its more important to me that any synonomy is clear when I want to check for a specific plant in VASCAN which is named differently in POWO. Most of my reference books do not use exactly the same naming schemes as each other and they don't magically update either but with a little effort I still can figure out which plants are described.
My overall feeling is that the taxonomy changes that I have seen over the past 40 years are mostly helpful, adding and clarifying our understanding of how plants are related to one another as well as our changing ideas about what is useful to name and how that naming might be best accomplished.
We are dealing with the same problem that we have always had since the first person named a plant. I don't think I would recognize a world where we all got it right the first time or agreed on everything.
Thanks for the reminder to have another whip round the urtica ids in Manitoba!
I would just go ahead and commit the swap after CNC. We absolutely have both native and non-native Urtica species here in southern Ontario, and it will be interesting to see the geography.
Ok, the CNC is upon us. How about this: why doesn't anyone who is interested and has a bit of time during the CNC try to refine some set of the existing u. dioica IDs to either u. dioica dioica or u. gracilis.
This will be helpful no matter what we do curator-wise. If you are pressed for time and want to go fast, you could just 'diamond mine' for observations that can definitely be confirmed to be u. dioica dioica and just speed past the rest. Feel free to also recruit anyone who might be interested who I missed tagging.
To make the request more bite-sized, it would be particularly helpful if anyone could clear through one or more of the currently listed regions of potential overlap, to hypothesis test whether there appears to be genuine overlap in inat observations:
California: 4,602 obs
Washington: 852 obs
British Columbia: 2,860 obs
Alaska: 140 obs
Ontario: 1,918 obs
Quebec: 430 obs
Newfoundland and Labrador: 104 obs
Nova Scotia: 135 obs
New Brunswick: 55 obs
Maine: 57 obs
New Hampshire: 58 obs
New York: 949 obs
Massachusetts: 803 obs
Connecticut: 157 obs
Rhode Island: 106 obs
New Jersey: 530 obs
Pennsylvania: 1,670
Ohio: 497 obs
Michigan: 836 obs
Missouri: 103 obs
Oklahoma: 6 obs
West Virginia: 55 obs
Maryland: 526 obs
DC: 69 obs
Virginia: 326 obs
Kentucky: 33 obs
Tennessee: 66 obs
North Carolina: 170 obs
Alabama: 2 obs
Georgia: 9 obs
Florida: 6 obs
Mexico: 226 obs
The Identify link is (change the place as you wish):
If you have previously been identifying some observations as just plain u. dioica, it may be helpful to also check your 'reviewed' observations, or add reviewed=any to the end of the link, i.e.:
On identifying the 2 taxa:
One clear example of an Urtica gracilis in fresh fruit (fruit still yellow-green).
The female, yellow-green fruits are the top of the plant, and the brown, withered male flowers are at the bottom of the plant:
https://www.inaturalist.org/observations/175285117
I still need to learn if, in U. gracilis, the female flowers / fruits are always at the top of the plant, and if the male flowers are always at the bottom of the plant.
Some use the distribution of the hairs to ID the 2 species, but my key offers a distribution of "stinging hairs", and I have yet to know whether hairs are stinging or not without feeling the sting.
@stewartwechsler – The "stinging hairs" are the long, crystalline-looking, hypodermic-needle-like hairs.
This Wikipedia page has a good close-up that shows the two types of hairs on U. dioica (I think correctly ID'd):
https://en.wikipedia.org/wiki/Stinging_plant
Thank you @ddennism I can now see the difference, at least on that Wikipedia example.
Immediately after the above comment linking to U. dioica stinging hairs on Wikipedia, I found these great iNaturalist close-up illustrations of U. dioica stinging hairs. 2nd to 10th photos.
I am certainly not an expert in urtica but I just skimmed through all of the Missouri observations (one of the smaller states on my list) to see if I could tell and none of them have those dense stinging hairs like those photos show.
I just skimmed over Delaware, and found the opposite — mostly U. dioica (s.s.), with cordate leaf bases, big leaf teeth, many stinging hairs on upper leaf surfaces; and when fresh female inflorescences present, lacking any male inflorescences on immediately-lower nodes.
This is consistent with Woodland (1982) who mapped U. dioica s.s. to the eastern seaboard of NE USA, Appalachians, Maritime Canada, and only a few sites inland (mostly around cities and Lake Ontario). Consistent with human introduction. But I didn't realize until now just how common the Eurasian taxon is in northeastern North America.
I think it would be very inappropriate to do the U. dioica (s.l.) --> U. gracilis transfer (floated above as option 2), at least for the northeastern USA and Canada. Lots of U. dioica s.s. out there, it turns out.
The case concerns this specific scientific publication:
https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.162.2.1
Let's wait for the next publications. Actions should definitely not be taken too quickly, hastily and based on too few publications on the topic, as this is anti-scientific and unnecessary.
@ddennism I hadn't found anything in any keys about the 2 taxa being distinguished by one having cordate leaf bases, and big leaf teeth, and the other not having them. Can you give us a reference for that? Also, not having male inflorescences on one node under a female inflorescence doesn't make the plant dioecious. On the gracilis observations I could find, with plants showing a high percentage of their inflorescences, all of the female inflorescences were on the top half, and all of the male inflorescences were on the bottom half, so most of the gracilis inflorescences of one sex would have another inflorescence of the same sex on the node below. Additionally I wasn't suggesting U. dioica dioica was native, only that calling it "introduced" would have many people in North America believing "Stinging Nettles" that they know as "Urtica dioica" were introduced to North America, which would harm stinging nettles in landscapes where people were managing for all natives, even though most of them, at least in the Pacific Northwest, would be the native Urtica gracilis.
Another point of interest: The computer vision is actually quite good at distinguishing u. gracilis from u. dioica ss, even without the flowers. It almost never mislabels the existing RG u. dioica dioica observations as u. gracilis (and for the ones where it does, I think it may actually be right), and only occasionally mislabels RG u. gracilis as u. dioica ss. It seems to be doing this pretty reliably even just from the leaves and a bit of stem. The fact that it occasionally mistakes u.gracilis as u. dioica ss is to be expected, because the u. dioica training set contains a lot of u. gracilis, and its accuracy rate appears in line with the accuracy of its training set. The fact that it can do this strongly suggests leaf shape, something about the stem morphology, and possibly something about the habit are decent features, because that must be what it is going off when it cannot see the flowers.
One reason that is significant is that I think it perhaps should temper any sense of urgency about actually making the swaps. If +/- the majority of new uploads from users relying on CV are already classified correctly anyway, then they are not dramatically increasing the rate of errors in the dataset, and many or most are not seeing the incorrect introduced status. If the rate of new CV mis-IDs is not too terrible, it increases the viability of significantly mitigating the problem through the 'ID blitz' strategy.
Ok, having read this entire thing, it seems very obvious that these two HAVE been separated into separate species, and there is decades of work behind this decision. This does not feel like a case of excess splitting which I myself have seen in certain taxa.
I would tend to agree that it is a VERY BAD THING if we are telling people that a native species is invasive (technically called introduced, but people make the association as described above). Now, I do agree with @ddennism that there are definitely a lot of the introduced species in the North America right now, but as he demonstrated, we can go back and determine that after.
For now, the city nature challenge is upon us. We need to make a decision, and I think the one that seems like it will do the least harm will be option 2. We can always go back through after, and do the proper checking in the future for which U. gracilis are actually the subspecies. For the moment, however, when we are telling novices about the plants of their region, we should make sure they know that there are native Urtica species which serve important functions in their native habitats.
@stewartwechsler -
For the leaf shape and teeth traits:
https://gobotany.nativeplanttrust.org/species/urtica/dioica/
(I have also seen these mentioned in several other places)
I should have been more specific in my comment re: the relative positions of the male and female flowers. The lowest female flowering node on U. gracilis ssp. gracilis should have a node with male flowers below it (as long as the flowers are fresh). Plants with bare nodes below the lowest female node are more likely to be female U. dioica than U. gracilis, at least out east. This is the point I was making.
However, out west (and in Central and South America) there are a few forms of U. gracilis (holosericea, etc.) that regularly produce a few female nodes at the lowest flowering nodes. This is not relevant to the Delaware plants I was skimming but is generally relevant.
See the 2014 "weeding the nettles II" paper for more details.
I don't understand what the rest of your comment is meant to be responding to.
@ddennism Thank you for the reference for the cordate leaf shape (dioica), and tooth sizes (larger on dioica).
Re: the three options initially outlined (and listed below), I don't think any are ideal. #1 is best. If a "complex Urtica dioica" taxon could be erected that would be better than reverting to just genus.
The European U. dioica ssp. dioica is generally uncommon but widespread in eastern Canada, mostly in disturbed ground in urban areas and around farm yards. So we don't want to automatically change U. dioica (s.l.) records to U. gracilis. I find the new spring growth to be difficult to ID, especially from photos where habitat is unclear, because the leaves of both varieties are fairly similar in shape at that stage and I think the teeth are proportionately bigger on the early leaves of gracilis.
1.) Use curator actions to revert almost all u. dioica IDs in North America to genus
2.) Use curator actions to move almost all u. dioica in North America (except u. dioica dioica) directly to u. gracilis
3.) Document a manual deviation from POWO's taxonomy, then use curator actions to move all existing u. gracilis IDs back to a subspecies of u. dioica (u. dioica gracilis)
I think we might consider two other courses of action:
4.) Manual re-examination of all "U. dioica". (This is essentially the status quo.)
5.) Like option 2). above (U. dioica --> U. gracilis), but restricted to areas of North America without known U. dioica (s.s.) introduction. We could use the distribution map in Woodland (1982) to guide this change.
I've been skimming Urtica dioica s.l. observations across the continent along with @stewartwechsler and @wildskyflower. So far, I haven't found many instances of U. dioica s.s. outside of the range shown in that paper from the eighties (kinda surprised tbh). Woodland mapped the Eurasian taxon to maritime Canada, the east coast of USA, along the spine of the Appalachians, and around Lake Ontario. (With a few sites inland, at large cities).
A lot of the observations are in areas on the west coast, for example Washington, that seem to have no or almost no u. dioica dioica, so that could be removed from the u. dioica dioica atlas with marginal to no impact on accuracy of the results, while significantly mitigating the disruptiveness. There aren't nearly as many total observations on the east coast; New York is the biggest and it is only like 1000.
I'm trying to figure out which other states could also be removed from the atlas. So if we find out which states we can't remove and then just ID blitz those that may be good.
I also don't think there is a huge reason not to create a complex when we do it.
Oh I strongly disagree re: making a complex. See above. iNat has a global scope. There already exists a notion of a dioica complex for Eurasian taxa. We can't just ignore that because it's convenient for North Americans.
I am coming to this late but I feel strongly about not wanting to default anything to either U. dioica or U. gracilis in areas where both occur. I happen to be in an area where both occur, and it is highly relevant which one an observation is, because one is a native plant that is becoming uncommon largely because of being displaced by the other, whereas the other is an invasive species. And even if the native one is more common overall, I definitely see around where I live, the introduced one is WAAAY more common. In fact, it's really hard to find the native one in my town, and part of it is that the invasive one seems to outcompete it.
I agree with the concerns given above, which is that we could cause harm by encouraging people to pull out the native species, and/or encouraging them to promote or leave the invasive one.
I think you could ideally handle this differently by region. Defalt to genus in regions where they overlap (perhaps within a ceratin radius?), default to one in regions where there is no overlap.
@ddennism There does indeed exist a notion of a u. dioica complex in the literature, and as far as I can tell it includes u. gracilis. For example:
Pulling the sting out of nettle systematics – A comprehensive phylogeny of the genus Urtica L. (Urticaceae)
has a 'u. dioica clade', whose members are:
u. australis
u. perfconfusa
u. aspera
u. sykesii
u. incisa
u. taiwaniana
u. papuana
u. atrichocaulis
u. angustifolia
u. gracilis (and all subspecies)
u. massaica
u. simensis
u. dioica (and all subspecies)
u. bianorii
u. atrovirens
u. kioviensis
u. platyphylla
Refers to the concept of the 'u. dioica complex' by name constantly, because the stated goal of the paper is to determine what actually belongs in the complex, and how they are related. Here is the final paragraph of the introduction verbatim:
A recent phytochemical and molecular study (Farag et al. 2013) showed that the relationships in the Urtica dioica-complex are quite different from what the current taxonomy suggests, but also that standard molecular markers are able to provide a well-resolved phylogeny of the genus. Based on this fact, the present study resolves the relationships in Urtica dioica with a special emphasis on western hemisphere taxa. Taxonomically, the redefinition of infraspecific entities as carried out by Woodland (1982) is the starting point. Relationships are clarified for the remaining taxa of the Urtica dioica-complex in Central and South America and taxa from other continents that have been associated with them in the literature. Additionally, the question of whether these taxa should be indeed included as infraspecific taxa under Urtica dioica is addressed.
It then recovers the same clade as above as the complex, and then says that the reason they need to elevate u. gracilis to a species is so that they don't have to demote the australasian species in the complex to subspecies.
THE GENERA OF THE URTICACEAE IN THE SOUTHEASTERN UNITED STATES
Is from 1971, from before u. gracilis was demoted to a subspecies, and explicitly refers to it as being in the u. dioica species complex:
Urtica dioica in the broad sense seems clearly to be a circumpolar species complex.
Their concept of the complex is :
u. dioica
u. gracilis
u. procera (u. gracilis gracilis in inat taxonomy)
u. angustifolia
Which, referring to the cladograms in the more recent studies, is the exact same clade they are still calling the u. dioica complex today (+/- the additional species they have added to it since 1971).
So we are on solid ground with a lot of available agreeing citations from both continents if we create a 'u. dioica species complex'.
Edited to add:
I managed to get a copy of the most recent publication I can find which uses the phrase 'Urtica dioica complex', Disparity between morphology and genetics in Urtica dioica (Urticaceae) and I think it is the source of the confusion about whether there is a separate European notion of a 'complex' here. They appear to refer to both 'u. dioica s.l.' and 'u. dioica s.s.' as a 'complex', but don't ever actually actually define 'u. dioica s.l.'; they just say to go to the first paper I listed (the one with the 'u. dioica clade') for a list of species in the complex s. l. When they call u. dioica s.s. a complex I think they just mean the subspecies, some of which may or may not be elevatable at some point.
They also say:
Whereas U. dioica s.l. seems to be well delimited (Henning et al., 2014; Grosse-Veldmann et al., 2016), the internal classification of the group is unstable and varies between sources (Domin, 1944; Geltman, 1990; Pollard & Briggs, 1982; Weigend, 2005, 2006; Henning et al., 2014; Grosse-Veldmann & Weigend, 2015).
So I think they are saying that the 'u. dioica clade' is the complex we should be able to regard as well-delimited.
Regional inspection and identification is likely the surest route to making the taxonomic change. After this flag was raised I examined and manually changed the observations that could be identified as U. g. holosericea. This taxon is quite distinctive from ssp. gracilis. The resulting atlas appears to define the occurrence adequately, the intermountain western states The taxon U.g. gracilis appeared along the north California coast north to Oregon and Washington, All are west of the Cascade crest. The regional variances of the NA taxa require regional knowledge to sort out and change the observation set.
@wildskyflower, Yes, that recent paper was what I was referring to above. They primarily use "complex" in that paper to refer to a polyploid complex involving Urtica dioica (s. strictissimo) and various diploid subspecies. This is a very different use from the use of "complex" to refer to the clade containing U. dioica and U. gracilis.
I think it's usually best to avoid the creation of "species complexes" on iNaturalist when there are multiple distinct uses of them in the active literature. Leads to greater confusion and quibbling down the road, and in this case might accidentally reflect North American geographic bias.
@loarie So, this might be completely impossible, but could we be able to make individual projects containing all the current observations in U. dioica, U. gracilis, U. dioica ssp. dioica, and other Dioca species respectively that would not change if we were to revert the taxa. That way, people who are more interested in the more niche Dioca species could use the one project while allowing for the others to either be rolled back to genus or moved to species? I feel like something like that could make this a lot less painful on IDers in the future.
This suggestion looks like a good solution and should be explored.
@ddennism As the paper you are talking about says, the 'u. dioica species complex' sense is a well-defined, stable, semi-formal, monophyletic group of closely related species with a more than 50 year history of being referred in the literature to as a 'species complex'. Additionally, a 'polyploid complex' is being referred to by this particular recent paper, but it is just referring to the subspecies. The paper does not create or attempt to create any question that the 'species complex' terminology cannot continue to be used to refer to the species complex. POWO's own source for the u. dioica/u. gracilis split, "Weeding the Nettles II", uses the species complex terminology extensively.
In most interactions I have had with European botany experts through this site, they have been totally fine with leaving 'polyploid complexes' as species-level entities for inat purposes. I think you can see this reflected in the fact that no publications mentioned here have even hinted at elevating the subspecies to species. In fact, one of the only 'lump'-style deviations from POWO I have ever entered was on behalf of Europeans, asking that a polyploid complex not be elevated to species-level. This is because treating them as subspecies is unambiguous to experts (even if it is not how they personally would treat it in their research), is suitable for all data export purposes, and much more convenient for IDing. @abounabat may know more about this kind of thing, or at least who better to tag.
Yes, I think that's all true. None of that really speaks to my objection: I still think it's usually best to avoid the creation of "species complexes" on iNaturalist when there are multiple distinct meanings of them in the active literature. As you brought up earlier, the question of rank between subspecies vs. species within U. dioica s.s. appears to be an active area of research. This could be a problem for us down the line. We can't handle nested complexes.
If you do go ahead anyway and create such a complex, please do include the Australasian and African taxa (omitted, for example, in the 1971 paper; I don't want to get into a long tangent about this, but your argument in above comments that there has been a single, stable concept of a "Urtica dioica species complex" over time is simply not true. For example, in that same 1971 paper they refer to a circumpolar complex. So, uh, please don't use that version of the "stable" concept! haha.)
The 1971 paper is primarily a key to urticaceae present in the Southeastern United States. They doesn't make any claim that their list of species in the complex is as exhaustive worldwide as the 2016 list. They also couldn't possibly be as exhaustive, because at least 5 of the species on the 2016 list weren't described/were split more recently than 1971: 2016 (u. perconfusa, u. sykesii) 1975 (1975: u. taiwaniana) 1983 (u. atrichocaulis), and 1992 (u. bianorii). None of the additional species on the 2016 list are excluded from their concept of the complex, they just aren't mentioned at all. The clade those 3 species represent is the exact same clade at the 2016 list though.
We don't need to handle nested complexes, because we already have what they refer to as the 'dioica s.s' complex as the subspecies of u. dioica. They only suggest one taxonomic change to anything, which is to elevate u. dioica cypria to a full species outside u. dioica s.s., but still within u. dioica s.l. (the species complex). There is no disparity in their terminology with how it is on inat.
Again, if you can find and loop in European urtica experts on whether the notion of the species complex sensu lato is confusing to them or negatively affects their ability to export and use inat data, that could be a useful addition to the conversation.
into U. dioica sensu lato and U. gracilis. haven't looked to see if there are other output taxa