Content Author Object Flagger Flag Created Reason Resolved by Resolution
showy goldenrod (Solidago speciosa) ddennism Fri, 21 Aug 2020 18:33:34 +0000

its subspecific taxa are species-level taxa according to POWO.

Not Resolved



From the FNA treatment, and

S. speciosa (s.l.) --> [S. speciosa (s.s.), S. jejunifolia, S. pallida]
S. speciosa var. speciosa --> [S. speciosa (s.s.), S. jejunifolia]
S. speciosa var. jejunifolia --> S. jejunifolia
S. speciosa var. pallida --> S. pallida
S. speciosa var. rigidiuscula --> S. rigidiuscula

S. speciosa var. erecta --> S. erecta (currently exists in our taxonomy)

Posted by ddennism 7 months ago (Flag)

This is the treatment used on Semple's web page, which I'm inclined to follow for Solidago classification. (Although Weakley has announced he'll be recognizing Oligoneuron again, which will ginger things up.)

Posted by choess 7 months ago (Flag)

S. rigidiuscula and S. jejunifolia taxon changes drafted here:

S. pallida is already in the iNaturalist system.

S. speciosa subsp. speciosa to S. speciosa sensu stricto might be tricky.

Plus, many things in S. speciosa in the current sense will probably need to move - maybe can use an Atlas for this, at least in part. The new species are mostly allopatric, but not completely, and maybe not completely known.

(all this is from the Semple website at University of Waterloo and papers cited therein)

Posted by ddennism 4 months ago (Flag)

S. speciosa (sensu stricto) added as an inactive taxon here:

State- and province-level atlases for the destination taxa added here:
S. jejunifolia:
S. pallida:
S. rigidiuscula:
S. speciosa (sensu stricto):
S. erecta:

Posted by ddennism 3 months ago (Flag)

Regarding S. speciosa subsp. speciosa:

According to the old FNA treatment, this subspecies includes the varieties rigidiuscula and speciosa (var. speciosa including the jejunifolia entity).

Based on the locations of some of the observations of S. speciosa subsp. speciosa already on iNat, some people really are using the subspecies in the umbrella-of-varieties sense.

Therefore, the taxon change should be:
S. speciosa subsp. speciosa --> S. jejunifolia, S. rigidiuscula, S. speciosa (s.s.).

Drafted here:

Posted by ddennism 3 months ago (Flag)

Maybe a Solidago speciosa species complex taxon should be added, as referenced in the article? That way the IDs get bumped to that, instead of section, in range overlap areas when the splits are committed.

I added the source (POWO) and key to identification to the main taxon change.

Posted by bouteloua 3 months ago (Flag)


The main change is drafted here:

Posted by ddennism 3 months ago (Flag)

@bouteloua - Adding a species-complex taxon is a good idea. Annoyingly their concept of "complex" seems to include overlapping complexes, which we don't really have support for on iNat. Specifically, S. erecta apparently is a "peripheral member" of their S. speciosa species-complex and a (full?) member of their S. bicolor species-complex.

I'll draft an erecta-free complex for now.

Posted by ddennism 3 months ago (Flag)

In that paper it appears that Semple has data that could be used to test the hypothesis that these are separate species, but does not do so. Interpreting discriminant analyses in taxonomy is difficult, because what you want to know is usually, "Are these distinct species?" while the analysis tells you, "If we assume that these are distinct species, can we use this data to tell them apart?"

An extreme example to illustrate the problem is: suppose you have a single character, ranging from 0 to 1 and measured to the nearest 0.1, with perfectly continuous variation. There are a dozen individuals at 0, a dozen individuals at 0.1, a dozen individuals at 0.2, a dozen individuals at 0.3, and so on. You draw a line across that variation and separate the individuals into two groups, e.g., "0.3 or less is group A, 0.4 or above is group B", and run a discriminant analysis. The analysis should tell you that the two groups are distinguishable with 100% accuracy. The answer to, "If we assume that these are distinct species, can we use this data to tell them apart?" is, "Yes, perfectly!" That answer will be the same no matter what value is used as a break point to create two groups. Now suppose you assign a few individuals with values of 0.4 and 0.5 to group A, and a few individuals with values of 0.2 and 0.3 to group B and run a discriminant analysis again. The two groups will still be distinguishable, but the accuracy will be lower, presumably 90-something%.

Basically, 100% accurate assignment tells you that your groups do not overlap, but does not tell you whether or not you have distinct species. Less than 100% accurate assignment tells you that your groups overlap, meaning that the putative species are not distinct in the data used in that analysis. That doesn't necessarily mean that they aren't distinct species, but if you were weighing the evidence for and against on a balance scale, you'd put that analysis on the "against" side.

I interpret Semple's paper as providing evidence that these are not distinct species.

Posted by aspidoscelis 3 months ago (Flag)

That said, I don't have personal experience with these plants and do not know if there is other evidence to put on the "for" side of the scale--only that the analyses presented in that paper should go on the "against" side.

Posted by aspidoscelis 3 months ago (Flag)

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