Taxonomic Swap 101446 (Guardado el 03/10/2022)

Añadido por mftasp en jueves, 11 de noviembre de 2021 a las 10:03 PM | Resuelto por mftasp en lunes, 03 de octubre de 2022
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I am not sure how this process usually works on iNat or what sources are considered valid authorities, but this is a bad taxon change. There are many differences between P. serotina and P. alabamensis, and they often occur right beside one another with low rates of hybridization. Indeed, I see both every day because they are common in the woods surrounding my home and in the surrounding community where I work as an arborist. In fact, I have found only one hybrid so far, and I am only confident it is a hybrid because the parents are sufficiently different that the hybrid exhibits intermediate traits that would never be found in either parent species. There are so many varieties that get reclassified as species on much less than what divides P. serotina and P. alabamensis. Is there some new research showing closer genetic relatedness than would appear from phenotype?

In my extensive hands on experience with these in the wild, these taxa are very much different species. It has always puzzled me how P. alabamensis was ever classified as a variety of P. serotina to begin with.

Anotado por corsontreeservice hace más de un año

Just for the record,

Alabama cherry has larger, rounder leaves, with a blunted rather than a pointed tip.

The upper surface of Alabama cherry leaves is rough and dull rather than smooth and shiny.

The lower surface of Alabama cherry leaves has conspicuously raised veins rather than being flat.

The lower surface of Alabama cherry leaves are covered with hairs, densest around the veins but covering the whole surface. In contrast, black cherry leaves are entirely smooth except for short lines of hairs flanking the midrib near the base, and even those are sometimes absent.

The result of the above is that Alabama cherry leaves have an e ntirely different texture and feel from black cherry, and they can be distinguished by touch alone.

Alabama cherry leaves emerge later than black cherry in the spring and then shed again later in the autumn.

The petioles of Alabama cherry leaves are shorter, thicker, with a prominent groove, and they're covered in hairs. In contrast, black cherry leaves have longer petioles, hairless, and without such a prominent groove.

The winter buds of Alabama cherry are slightly larger than black cherry.

Alabama cherry petioles, pedicels, peduncles, calyxes, and twigs to the previous seasons growth are covered in hairs. Black cherry is entirely glabrous. The persistent hairs on the twigs are the best way to ID Alabama cherry in winter condition.

Alabama cherry is a smaller understory tree than black cherry, with a more twisting and sprawling form.

Alabama cherry tree is more restricted to dry upland habitats, becoming more common on rocky slopes and rarely found in lowlands, while black cherry is much more versatile in habitat.

Alabama cherry flowers and fruits a couple of weeks to a month later than black cherry, though there is short period of overlap in the flowering.

The bark is the most similar between the species. In my experience, the immature bark of Alabama cherry is slightly paler than black cherry, but it's not enough to base an ID on.

There is considerable reason to treat these as separate species. Perhaps most of all Alabama cherry is entirely sympatric with black cherry, overlaps in its flowering peiod, and yet hybrids are uncommon. Among the thousands of Alabama and black cherry I have closely inspected, I have found only one hybrid, and I have been consciously looking for hybrids in that time.

Anotado por corsontreeservice hace más de un año

Hi @corsontreeservice, they are still different taxa.

Our external taxonomic reference, Plants of the World Online, simply treats them at a different rank.

For what it's worth, the draft change had been up for nearly a year, in response to a flag that I can no longer find. I only committed it yesterday after no comments for a year.

Anotado por mftasp hace más de un año

@mftasp

If I had seen the flag, then I would have objected. I don't know if it would have made a difference, since Plants of the World Online says what it says. There is already a proposed taxon change there to species rank, but it doesn't appear to have been addressed yet.

This is just annoying because the iNat database is now less correct than it was yesterday. Hopefully, PotWO can get around to making the correction and then it can also be corrected here in ... what, a few years? Is that not aggravating?

Obviously, iNat can't base its taxonomy on what random users insist is the case, but that doesn't mean the random users are always wrong either.

Anotado por corsontreeservice hace más de un año

To be honest, I am far less worried about a change of rank, like this, where correctness is purely a matter of opinion, compared to a lot of changes in which POWO consider synonyms species that almost everyone else treats as valid.

If you feel strongly that separate species is a better way to treat these, I'd encourage you to flag the subspecies and start up a discussion. Tag a few people who you think have an opinion or contribution to make, and let's get it moving.

Anotado por mftasp hace más de un año

@mftasp

I admit this taxon has some sentimental value to me because it kind of kicked off my interest in learning about the woods here. I also suspect I know this taxon at least as well as almost anyone, since it is an uncommon species that happens to be very common in the woods surrounding my home.

I appreciate your time and patience. I may do as you advise.

Anotado por corsontreeservice hace más de un año

No worries. I sometimes find it useful to @ a few of the top observers and identifiers to they become aware of the flag.

Anotado por mftasp hace más de un año

I was unaware of this flag; if I had seen it I certainly would have disagreed with it strongly. The Flora of the Southeastern United States (of which I am the lead author) will continue to treat these at species rank. Because they are species. ;-). Other regional experts, like the Alabama Plant Atlas agree in treating this at species rank.

This change is one of many that get made "because POWO says so". But, there's something wrong when the flow of knowledge is imposed on local/regional/national experts by an "aggregator" (supposed) of knowledge based in Kew, who, by definition, knows less about taxonomic issues of this kind (lumping splitting, rank changes at species/variety/subspecies ranks). When I have complained in the past, it's suggested that I contact POWO (essentially this amounts to Rafael Govaerts) and have him change POWO to fit our regional knowledge. When I (or others) do this, the taxonomy is generally changed to what we, the experts closer to the ground who actually know the taxa, think it should be -- which is as it should be.

But it is frustrating to see changes made in the wrong direction (towards older and more outdated taxonomic understanding, because that's the information that got to Kew), then requiring changing back through extra work.

BTW, I get it that iNaturalist wants to use one system of taxonomy, but the most important issues to maintain global consistency on are the structure and "taxonomic scaffold" at genus and higher ranks. There needs to be consistency globally of whether the Magnoliaceae is 2 genera or 16. But this is not that.

Anotado por whiteoak hace más de un año

Hi @whiteoak, as a regional taxonomist myself, I agree with a lot of what you say. When I wear my iNat curator hat, though, I have to try to slot things into our taxonomy, and follow POWO as much as possible.

I can see you've opened a flag for it (https://www.inaturalist.org/flags/589813), I will link back to this conversation fo rcontext.

Anotado por mftasp hace más de un año

Hi @mftasp -- yes, I do fully appreciate with "as a regional taxonomist myself, I agree with a lot of what you say. When I wear my iNat curator hat, though, I have to try to slot things into our taxonomy, and follow POWO as much as possible." I acknowledged that in my "BTW..." paragraph.

I guess ultimately the frustration is that iNaturalist has a legitimate need to follow a "global consensus taxonomy" -- it can't use one family or genus level taxonomy in Tasmania, another in Australia, and another in Brazil. But at the finest levels, decisions should be made by those who know the taxa best, have the most up-to-date information regarding their taxonomy, and that info should flow UP to the aggregator, POWO. We haven't successfully created a structure for that. Several of us in North America (FNA, SEUS Flora, CalFlora, etc.) are discussing ways to pull together a consensus checklist for vascular plants of North America, that then could be used by POWO (or reconciled against other continents for taxa with multicontinental distributions.

The "Prunus serotina complex" as treated on iNat has plenty of other issues. It currently has both subspecies and varieties (and those different ranks, as usual, NOT intended to convey any different meaning or used hierarchically in a legitimate way) -- ssp. eximia, but var. rufula. There are 45,645 observations (!!) of "Prunus serotina", but only 125 of Prunus serotina var. serotina, which 95% of the "Prunus serotina" records actually are. Put another way, the "Prunus serotina complex" is an example that actually NEEDS some top-down taxonomic order imposed on it via curation, but this reduction of Prunus alabamensis to another poorly handled infrataxon under Prunus serotina s.l. doesn't help, and actually makes it less likely that additional observations of this narrowly distributed, habitat specialized species of conservation concern will be made.

@loarie -- I hope there can be some additional discussions and solutions about the imposition of a casually collated global standard (POWO) that also falls behind taxonomic progress on lower level (species and infrataxa) taxonomic decisions regarding taxa limited in distribution to a small geographic area and a single country.

Anotado por whiteoak hace más de un año

@whiteoak I completely agree that in an ideal world regional taxonomic decision from FNA, SEUS Flora, CalFlora, etc. making would flow up to aggregators lie POWO resulting in a global consensus taxonomy that could be used by things like iNat/IUCN etc that aren't focused on / built for original taxonomic decision making. What do you think are the best ways to move constructively forward to that goal? Happy to help facilitate in any way

Anotado por loarie hace más de un año

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