Overlooked dandelion diversity in BC (and everywhere in North America?)

Nature Talk
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You have an interesting study, but I think you need to take crbjork’s key into account before I can come to the same conclusions as you have as achene color doesn’t seem to be as important there. It’s pretty clear that most of the North American taxonomy dealing with introduced Taraxacum species doesn’t work well. The question is, does that support creating a finer, more European style system or lumping everything together. In my mind, this fact of bad flora treatments doesn’t support or diminish support for either, it simply informs what philosophy we want to take on the species concept. I tend to be on the splitting end of the spectrum and while I’m not sure how I feel about how fine the microspecies taxonomy is in Taraxacum, I am open to the idea.

Regarding your second post, I’m not particularly sympathetic to the argument from human taxonomy. Such an argument only leads to not recognizing subspecies or varieties at all. Such a taxonomy is inflexible and too imprecise for me to consider workable in many cases. Furthermore, I believe it would discourage the discovery of new species and the conservation of threatened populations. I can think of many examples where plants that were previously thought of as varieties turned out to be good species. What’s more, this argument doesn’t even apply well to the question of whether to recognize microspecies as humans are not apomictic.

Regarding the argument of public utility, I’m not particularly sympathetic to that argument in this particular context either. In the context of education, (e.g., teaching the best taxonomic categories to use and to not be dismayed by not getting to species level) I think there’s a lot to be discussed but taxonomy should ultimately reflect our best understanding of the world (and we can argue about what that is) regardless of how the public views it. To give some semblance of an analogy, high school students hating higher-level math and most students not ever using it in their lives is not a good argument for not articulating higher-level math (maybe an argument for not teaching it at certain levels, but certainly not an argument for not teaching it at any level).

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Abstolutely, there’s a great discussion about it here. I think if sections/macrospecies are distinct identifiable clades, people would be fascinated to learn that there’s more than “just dandelions”. It’s probably unnecessary to go further than that in most contexts.

What do you mean by a blinded trial? Would sending the same specimens to multiple experts and comparing their identifications count, for example? The paper I referenced above (Kirschner et al. 2016) has a test equivalent to that I think:

Four specialists collected achenes and usually also herbarium specimens of these species in six countries
…
Genetic analysis leads to the recognition of groups corresponding to species, with two exceptions out of 125 individuals (and one unclear case, see Discussion), and the accuracy of identification was nearly perfect, i.e. all the Taraxacum experts use the microspecies names in the same way and there is no identification bias associated with the person responsible for the determination.

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I find that, too, is becoming less true.

I am trying to get my shepherd’s purse thread reopened for a similar reason to what is being discussed here, viz., I have a hypothesis that there is more diversity in introduced populations than has been realized. People tend to see what their field guides tell them to see; if the field guide says that there is only one species, then people will see only one species.

That is also my big objection to today’s photo-based field guides instead of the old Peterson line drawings: if the field guide chooses to depict one species of a genus that has a number of similar species, people will tend to identify every plant of the given genus as the pictured species.

So the next question re: dandelions is: who is going to take the trouble to bring the European keys to other continents and parse out the introduced, weedy populations? The British Columbia paper is a good start, but that is just one province of one country on one continent.

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Call them Taraxacum UNofficinale

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I only ever see white fuzzy ones that have a greenish purple ish stem and when you snap the branch white stuff oozes out. (Sometimes they snap when I accidentally step on it or when I pick one to blow)

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Pretty much all the dandelion species look like that. The distinctions between the species are very technical.

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Why did you withdraw that comment, it was one of the funniest comments on the forum.

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Yeah @will please reinstate it! We appreciate a little humor.

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@fluffyinca @raymie reinstated.

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This is patently false.

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POWO recently changed T. officinale to a synonym of section Taraxacum, which means it isn’t accepted as a species anymore. If you have an opinion on how that should influence iNaturalist’s taxonomy, there’s a discussion in a flag here.

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I encouraged that people recognized erythrospermum as a first start. Before that point, it was all lumped into officinale and I considered that the use of erythrospermum for ecologically and morphologically separated microspecies was at least some awareness to dandelion diversity.

I’m fairly sure myself and others are more than eager to collect, and properly identify the species. But there’s no (present) way to do so for the US to my understanding. I understand the sentiments here but until there is some method of doing this, it feels like we are being told to religious focus on a goal that is not yet possible. This is not something people can work on piecemeal, its a big group and it requires the taxonomic experts to start things off. We don’t know what species are here, we don’t know if some are undescribed. There needs to be guidance.

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As it’s already used as an aggregate on iNat, either way of dealing with it will work the same imo.

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I don’t care how many “species” of dandelions there are. I only care that we preserve any native diversity of Taraxacum, and potentially help people know which Taraxacums are safe to pull, and which we need to be careful not to pull, so they might pull out alien material without risking damage to any sensitive native populations. In his above key, Curtis Bjork offered what I think may be the most important distinction between native and alien Taraxacums (in North America?) in his first couplet, which indicates that if the Taraxacum isn’t at a high altitude, or a high latitude, and isn’t in a habitat of disturbed vegetation, we don’t really need to worry about pulling up rare natives, but at higher altitudes, and higher latitudes, in natural plant communities, we might not want to pull Taraxacums up, at least without having studied the shapes, and positions, of the bracts, and the lobing of the leaves.

The main risk I see of identifying Taraxacums only to genus, is a possible risk of identifying a native as a weed, or identifying a weed as a native. For lack of anything better, here, in the Pacific NW of North America, for lack of having a “Taraxacum Section Alien to PNW North America”, and for lack of anything better, I have started identifying the lowland weeds as Section Taraxacum, apparently with little risk of identifying a weed as a PNW native, or a PNW native as a weed.

Curtis Bjork’s first couplet:
1a Plants usually growing in wild vegetation at high elevations or latitudes; bracts sometimes strongly corniculate, the outer ones mostly erect to appressed, sometimes recurved or spreading; leaves mostly either weakly lobed or with simple lobes … (Native groups, not treated here)

1b Plants mostly in disturbed vegetation, mostly at low to middle elevations and latitudes; bracts not corniculate or with small, inconspicuous horns, the outer ones mostly spreading, recurved or reflexed; leaves mostly deeply lobed, the lobes in most cases longer than wide and often again lobed … 2 (Exotic sections)

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I honestly don’t see the point of chopping T. officinale into a bunch of inconsistently discrete ‘species’. People are still identifying T. officinale to species including on my observations when i upload as genus. I have a pretty good grasp of what a species is and honestly don’t understand how this is anything but a variable and diverse species. Maybe in 1000 years we get a bunch of endemic dandelions in each city, i don’t know. For now, in North America, I feel like the introduced ones should probably be lumped into officinale or else we should default to genus level being research grade when verified so they don’t keep popping up as needing ID (yes i know they can be marked as no further ID needed but given how popular the species is a lot just dont). Better yet just go with T. officinale and use subspecies and variants to deal with the genetic diversity if desired.

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Charlie makes a good point, Taraxacum “officinale” works better for the audience of iNaturalist to distinguish the weedy material in at least North America from any native material in the mountains, or the arctic, and better than “Section Taraxacum” that few people understand, and which may not be taxonomically accurate. I think this is better than calling the genus level “Taraxacum” “research grade”, which lumps the alien material with rare native material.

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Is it acceptable to work through dandelion observations (Needs ID and/or Research Grade), bumping them back to genus and checking “ID cannot be improved” to make them RG at genus level? I did this to a page or two but then realized it might offend someone - will it? If so, is there a better solution? It bothers me that there are so many with Community ID at species when they can’t really be identified that far.

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I’m not a fan of doing this unless it’s really for certain, like a photo of a sedge with just leaves from far away or whatever. People can get IDs from overall look if familiar with a species. I’m also reluctant because depending on what taxonomy you use, you really could get a species level Id from a blurry yellow blob picture or else you’d never get a species level Id ever without genetic analysis

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I’m not sure if you understood what I said. I specified dandelions, and I’m not intending to do this to anything else. I meant, given the current situation with the mess of dandelion taxonomy, is it appropriate to just call them all Taraxacum?

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I did understand what you said. I know you specified dandelions. I’m saying whether it’s appropriate depends on what taxa scheme we buy on to. I mean personally I don’t really ever use that “no further id “ button unless I believe the ID is actually wrong, but that’s a debate that happened long ago and I know people are allowed to use it how you do.

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