I’m just thinking about the staff coming back from their Easter weekend haha, “oh no, not dandelions again…”
13 Likes
@upupa-epops - Hahaha. Hey - I asked for their mercy!
1 Like
Here’s a four-year-old observation from Indiana I just came across that I’m going to confidently confirm at genus-level and mark “as good as it gets” - thought it might elicit a smile :-)
If this forum were an appropriate place to ask for an ID, hopefully you'd all be happy to confirm this is Taraxacum sec. Taraxacum, sp. taraxacum, var. taraxacum, f. taraxacum - or something similar, as it surely should be :-)
10 Likes
Just devise a catch-all name such as Taraxacum officially 
.
5 Likes
I’m just angling for one of the new micro-species to be named Taraxacum comradejonii - it’s going to be like how we can all have a star named after us :-)
8 Likes
It is timely. There’s no better day than today to coin some new names. ;)
2 Likes
that was what we were trying to do on iNaturalist before it got ruined. That’s my whole point. If you don’t like my idea that’s fine, but the reason i don’t share it with you is these sorts of responses. And i’m done discussing this now unless someone else has something different to offer.
2 Likes
It will not become a synonym, just a name to be rejected
No harm keeping the name for familiarity. I’m not sure but I would think it is europeans who are deciding things. It is a non-native weed in USA.
Those pesky Europeans. We should probably rename Taraxacum officinale to Taraxacum freedomfries just to teach them a lesson! 
10 Likes
Sounds like food.
That was a reference to: https://en.wikipedia.org/wiki/Freedom_fries
3 Likes
Looks like most of the Taraxacum species are triploids (2n =24) with others diploid or tetraploid, and no doubt higher polyploids. Polyploids have a reservoir of genetic diversity because they have more copies of each gene than they need. Even if they accumulate bad mutations, they are buffered for a while.
The longest ages of some plants (individual trees or clonal shrubs) are in the thousands of years. Some aspens and huckleberries are 10,000 years old or older, established as the glaciers retreated. It’s thought that most of the great diversity of the weedy dandelions has originated since the glaciers retreated. Extinction due to lack of genetic diversity isn’t going to be a big problem with these microspecies (much though we might wish – clear out this confusing diversity).
3 Likes
I think the paper “Taraxacum: ploidy levels, hybridization and speciation. The advantage and consequence of combining reproductive systems” is the best/clearest summary of the interpretation of Taraxacum’s behavior as a reproductive strategy and explaining the issues with interpreting the behavior in terms of a microspecies concept instead. Choice quotes below in case anyone has issues downloading it:
Many taxonomists feel not particularly attracted to the genus Taraxacum Weber ex F.H. Wigg., to say the least.
It was assumed that apomictic seed production prevailed in the large majority of the derived taxa, whereas sexual reproduction was said to be restricted to the primitive ones. Apomixis leads to fixed patterns of morphological traits within clonal families. The consequent, apparently consistent morphological differences between clones provided the basis for the extensive (micro-)taxonomy. However, sexual reproduction is more common than assumed: sexuality occurs in many sections.
Very many of the microspecies have been based on the assumption of full apomictic behaviour and consecutive genetic isolation. However, it is well established now that sexual reproduction is less rare than commonly was assumed, and this may have consequences for taxonomy
In Ruderalia and Erythrosperma, cooccurrence of sexual diploids and asexual triploids in mixed populations is very common in central and southern Europe. The following has been found: 1, apomixis is not obligate, polyploids show a variable (low) degree of sexuality by means of several mechanisms; 2, in mixed populations, hybridization, and introgression between ploidy levels takes place; this also leads to 3), a di-/ triploid cycle, that may bring extra potential for evolutionary response to environmental change. These processes may lead to: 1, the continuous production of new apomictic lineages (microspecies), 2, the fade-away of others (due to introgressive hybridization and selection), and 3, the generation of advanced diploids as well.
NB: their Section Ruderalia=Section Taraxacum (which contains T. officinale) on inat.
Sections in which these phenomena are present, are to characterise as evolutionary very dynamic, but at the same time as taxonomicaly very difficult to treat, among other things, because the “micro-species” concept is of limited applicability.
One of the other conclusions that has been drawn from these data is that there are
very many sexual plants co-occurring with the apomicts in the populations. This situation was hardly known by the taxonomists, who described hundreds of
microspecies, assuming that al plants are equally fully apomictic.
Completely contrary to the assumption hold by Taraxacum taxonomists, sometimes even the type material of a (micro-)species proved to be diploid.
A single 30 plant sample from a 2x/3x population in the South of The Netherlands, showed 16 clones, and a large sample of 262 plants from the Hedel population (see above) turned out to contain as many as 73 clones. The quite high figure for clonal diversity (0.94) suggests that almost every individual is a particular genotype (for details, see MENKEN & al. 1995; DEN Nus & MENKEN, 1996). Altogether, there is ample data that point to the occurrence of bidirectional hybridizations between (at least some) polyploids and sexual diploids where these ploidy levels co-occur.
In pioneer habitats, the almost 100% reproductive output, which is inherently independent of pollination, guarantees the triploids a succesful population development. On the other hand, there can be a shift to sexual reproduction in circumstances that favour genetic diversity.
the description at the species level of all discontinuities in the spectrum of apomictic morphs never will produce a realistic picture of the situation in those sections where these hybridizations occur.
8 Likes
Interesting stuff!
2 Likes
Huh that paper is 27 years old, yet the dandelion taxonomists are still out there describing new species. 51 new species described in this 2020 paper from a small region of Asia… I would love to see a conversation involving these different researchers and and hear their opinions and disagreements haha.
4 Likes
Yes it is puzzling; as far as I can see none of the paper’s citations actually engage with the substance of what it says at all. Here are some more relevant sources I could find:
“The Potential for Genetic Assimilation of a Native Dandelion Species, Taraxacum ceratophorum (Asteraceae), by the Exotic Congener T. officinale” have shown that invasive T. officinale readily hybridizes with native diploid taraxacum species, https://www.jstor.org/stable/4126094 (and does explicitly say it follows the macro species concept for t. officinale due to a lack of a viable microspecies concept for North America).
“Hybridization rate and genotypic diversity of apomictic hybrids between native (Taraxacum japonicum) and introduced (T. officinale) dandelions in western Japan” https://link.springer.com/article/10.1007/s10592-017-1014-y finds that 86-96% of surveyed dandelions in Japan are hybrids between T. officinale and native diploid species (it just takes the existence of T. officinale for granted and never mentions the word microspecies at all).
" Hybridization between European and Asian dandelions (Taraxacum section Ruderalia and section Mongolica )" https://link.springer.com/article/10.1007/s10265-002-0045-7 likewise finds that 82% of surveyed plants in Japan are hybrids of T. officinale and Japanese native diploids, and does say “In Taraxacum, gene flow can partly break down the boundaries between the agamospecies” and then explicitly rejects using the microspecies for that reason: “The broad nomenclature of Taraxacum officinale and T. laevigatum is used here, although most European taxonomists consider these species to be aggregates of distinct agamospecies that are more equivalent in rank to the sections Ruderalia and Erythrosperma (Kirschner and Sˇteˇpánek 1987).”
“Genome size variation among common dandelion accessions informs their mode of reproduction and suggests the absence of sexual diploids in North America” https://link.springer.com/article/10.1007/s00606-017-1402-2 Explicitly uses the T. officinale instead of microspecies. As the title suggests they did not find any pure T. officinale sexual diploids in North America, though they did exclude plants that looked like T. ceratophorum (which hybridizes with T. officinale per above), and acknowledge in the discussion that T. officinale might have some gene flow mediated through hybridizing with North American diploids, but do not really analyze that possibility. It also doesn’t uniformly sample all of North America of course.
7 Likes
What confuses me most (without having actually read super in-depth or contacted anyone involved) is that Kirschner et al. do seem to be testing whether their taxa are sexual or agamospermous, and cultivating them to determine how variable they are. But there still seem to be separate streams of taxonomy going on that aren’t fully engaging with each other?
3 Likes
It looks like Kirschner has possibly not written anything at all about Section Taraxacum since “Typification of Leontodon taraxacum L. (≡ Taraxacum officinale F.H. Wigg.) and the generic name Taraxacum: A review and a new typification proposal” by Kirschner & Stepánek in 2011 https://www.jstor.org/stable/41059837?seq=1. (though I can’t open the Ladakh book so maybe it is in there). That paper selects the deliberately microspecies-ambiguous lectotype, and says:
. In all the recent major floras of the former Soviet
Union (Siberia, the European part, the Far East, Kazakhstan
and Middle Asia, the former Soviet Arctic), Central Asia
(mainly including Mongolia and N. China), China and India,
the name Taraxacum officinale is used predominantly or at
least partly for what is generally understood as common dan-
delions. Flora Europaea (Richards & Sell, 1976) is earlier
but does not represent an exception.
non-specialists can continue in using the name T. officinale in the generally and traditionally adopted way: it is equal to what is called common dandelions
So I’m not sure if I would interpret them as just not engaging with the argument from before, or sort of just conceding the point at least re:Section taraxacum from a practical standpoint, without acknowledging that they are doing that?
Edited to add: Note that this is the primary source POWO cites for not accepting taraxacum officinale in POWO taxonomy
1 Like
You failed to mention reviewer #2.