What is the current state of the lumper/splitter debate?
 

The title says it all.

I haven't been deeply involved in orchid society for almost 30 years and things in and about taxonomy have clearly changed.

S. coccinea and S. cernua are now Cattleyas. Dockrullia has been absorbed back into Dendrobium. I've noticed lots of other stuff too..

Have genomic advances affected the definitions of genus and species? Is there more agreement about classification because of it? (The days of the gentleman-botonist are clearly over.) Who's the current best authority? Kew's POWO seems like a good candidate. What about other taxonomic groupings? Subgenera? Subspecies? Does rank-based taxonomy have a foothold? Academically? In the hobby? Has the web-of-life idea entered the picture?

Genomics is the current fad. It will eventually change. Authorities are self proclaimed. Many authorities do little or no fieldwork. Think of it as the Warring States period in Chinese history.

There's both lumping and splitting going on. While Sophronitis and the Brazillian Laelias are now Cattleyas (the Mexican Laelias are still Laelia) C. bowringiana, C. aurantiaca, C skinneri are now Guarianthe. So pretty much, all the intergeneric names have taken a beating. I'd say that there is more lumping than spitting. (Oncidium tribe for instance, and now Coelogyne has absorbed Dendrochilum and a few other genera, Vanda absorbed a bunch of genera, some other distinctive ones got lumped into Phalaenopsis) Since morphology and environmental considerations no longer have the influence that they used to have to put it mildly, DNA relationships have made some strange bedfellows. In the hobby, most of us don't change tags, at least for a long time. Because new information is likely to change things again. When addressing a plant, just say "Hey... YOU!":roll: Kew certainly isn't the only classification system but it is an 800 pound gorilla... it's the only source that AOS uses. The Kew website is much improved (even having some photos), listing synonyms, but still pretty unforgiving. orchidroots.org is pretty up-to-date with Kew (.com works too), a lot better for searching.

So is there more agreement? Depends on who you ask... I think most hobbyists are pretty frustrated, often resistant. If you enter a plant for judging you need to look up the genus du jour otherwise, nice to know but don't lose sleep over it. Maybe there is more agreement among the scientific community but I wouldn't bet money on it. "Publish or perish" is still the rule in Academe, so there's a lot of motivation for not agreeing.

In my opinion there will never be a final verdict. It isnt because scientists are incompatent or corrupt, it is because there is no real lines in how things are divided.

We all know how much orchids especially can blur the lines that humans draw. Lumpers and splitters dont neccisarily disagree on which organisms are related, they disagree on where the line that divides a species from a subspecies (etc.) lies. There is no objective answer to that.

As a hobbyist, what I find problematical with the lumping is that we tend to lose the habitat information that helps us actually grow these. The DNA data certainly shed a new light on relationships, which is what the science of taxonomy/systematics is about. Scientists need to follow the data. Here, there's a selective process as to which data define the structure that humans try to impose on nature. At some point, I suspect that there will be recognition that there are factors beyond the DNA that inform the relationships. And probably more refinements in understanding what the DNA data are telling us. (We already know that epigenetics, the processes that determine which genes are active, also are involved, and a vital part of evolution that facilitate the ability of organisms to adapt to environmental changes) So yes, science evolves, that's the nature of the beast. On the horticultural side (where we as orchid growers live) we still struggle to capture the information that helps us actually grow these plants.

I agree. Ultimately, I believe that the whole genus/species classification thing (probably any classification that attempts to be strict), is inadequate.

In the scientific community it'll take decades to find a reasonable replacement, and then decades more to work out the details and consequences.

On the horticultural side, I have no idea what to expect. It's not even obvious that a new framework would be entertained, let alone accepted. If accepted, then there's all that clerical work of mapping the current approach to its replacement.

It's an unpleasant (but ultimately necessary) transition for all involved. I doubt I'll still be around to watch, but it sounds like it would be fun. :)

Gardeners are concerned mainly with how to grow things. A plant botanist told me a superseded plant name that was given properly in the past is not incorrect. Many of the older classifications made more sense from a horticultural perspective, which is why there is no reason for hobbyists to change their labels.

That's right. You don't have to change it.

I leave my original tags in the pots and do not worry about it. Most plants have names we know them by as well as a scientific name. I think of it like that. Some of the names have changed a few times anyway since they started this renaming. With some of the older hybrids, it can be hard to find them under their new names.

Nobody I know calls me Homo sapiens sapiens.

Lumpers vs splitters is incredibly simplistic and downright inaccurate. To paint plant systematics and taxonomy as if this is a core debate is just silly.

The only thing that accurately describes people being upset that plants are renamed is this:

https://i.imgur.com/sbyfISQ.png

I think of taxonomy as an evolutionary history. It is a family tree. Family trees do not tell you about acomplishments and personalities of the members just the lineages.

I dont think its taxonomys job to tell us how to grow plants but I do agree that we need to learn more about orchids for the sake of conservation and cultivation. I am constantly digging for in-depth information beyond culture sheets, and beginner basics, but its isnt easy to find.

I struggle with the lack of info and inadequate detail about most of these plants but i would like defend the few scientists out there who work to further that. I think they rarely deserve the pushback that they get.

It's difficult with how fast information travels these days. And entire genus can disappear into another overnight, or vice versa. It's especially difficult when one goes to purchase--for example, Lycaste locusta was (is, sort of) the accepted name, but then it was frequently published as Ida locusta for a season. Many vendors still sell it as with a Lycaste tag. Now, it's Sudamerlycaste locusta, and there's no way I'm remembering that! :rofl:

-Christian

A few years ago I tried to find the correct pronunciation for "Ida" ... I had heard it pronounced "eyeda" by some, but "eeda" by others. Looked it up, and found that it was pronounced "Sudamerlycaste" ... an improvement? Why???? I can accept lumping and splitting... taxonomy/systematics seek to show relationships, and as the understanding of those changes with DNA results, genera change to reflect what is related to what. (I'm not changing my tags, by the way) But I REALLY wonder when an entire genus gets a name change, where I don't think relationships are different... What used to be Ida contained Lycaste relatives from South America... Sudamerlycaste. (Most of what's still "Lycaste" is Central American) Another one where this happened was all the Cochleanthes becoming Warczewiczella. In both cases it looks like just going from "easy to spell/pronounce" to the opposite without adding information.

Exactly! I'm no botanist, but it seems like useless shuffling.

I guess I'm that man yelling at the clouds. :p

I call my orchids whatever is on the tag. If I am corrected, I try to use the correct name (if I can remember/spell/pronounce it).

Sounds like this is a case similar to C. leopoldii vs tigrina.
The first person to describe the species with a name gets precident. If you find an earlier description, the plant has to get renamed the older name. In that case it isnt a rearrangment to illustrate changing understanding of relationships, its just people following the naming rules. Sometimes its annoying but its credit where credit is due.

In these two cases (where a whole genus name changed) I don't think fits the "priority" situation - that applies more to specific species names. C leopoldii vs tigrina falls into that situation. I can see changing a genus where there is new information - for instance, Schomburgkias becoming either Laelia or Myrmecophila... the plants were originally grouped based on flower morphology (those wavy petals and sepals), but the plants are really quite different.

There are so many factors in this discussion, that it is hard to cover all the bases. A couple of comments:

Earliest published name in a scientific journal takes precedence. This is a Taxonomy 101 rule.

As mentioned, any previously valid name may be used. EXCEPT: If you register plants for ribbon judging, or AOS judging; in this case, we must use currently correct names. This also applies when registering new hybrids with the RHS.

Next, why the changes (I hate all of them!). Much of the early naming was based on logical, but somewhat simplistic, criteria. Prime example: 4 pollinia = Cattleya, 8 pollinia = Laelia. Today we know that both genera have the same number of chromosomes, and DNA analysis reveals that the two groups are so closely related, that they should be one (via a detour through Sophronitis, which are also Cattleyas now).

While Taxonomists keep proposing changes, by no means all are accepted. My favorite Epidendrum vitellinum (1831)/Encyclia vitellina (1961)/Prosthechea vitellina (1997) actually has a proposal for yet another name change (to Pseudoencyclia, 2003), but it has not been accepted (yet). And, when Brassavola digbyana & glauca were moved to Rhyncholaelia in 2007, it was based on a proposal from 1918 (based on differences in the lip structure)!

My scientist side 'gets it', and my horticulturist side hates it.

We lost the person in our Orchid Society that kept up with all the name changes (he did all the registering for our shows, too).

It is not difficult to verify whether a name is current. For hybrids you enter the grex name in one of the databases (such as the RHS), and it returns all genera where the grex name is used. It is usually obvious which one is currently correct.

For species you can use Kew or Orchidroots. Same process.

Shouldn't DNA analysis lead to the final answer and the end of splitting/lumping?

The RHS database has gotten better. a lot more forgiving recently. And Orchidroots lists hybrids as well as species, is pretty up-to-date.

No. A person or panel must decide what DNA patterns represent significant differences. There will always be disagreement and reclassification.

Also, DNA shows relationships (what is more closely related to what) But the decision as to where to draw the "genus lines" is a human decision. Nature doesn't care, sometimes is messy.

Maybe I'm lacking respect for tradition, but I find the problem is born out of its adherence. If we don't restrict ourselves to genus and species, we could have multiple levels of categories and subcategories that capture any level of similarity. In that case, it would be, for example, both correct to call a plant Laelia purpurata and Cattleya purpurata, or perhaps Cattleya sub. Laelia purpurata, or whatever the nomenclature is decided to be. Of course a "genus" could still exist for taxonomists, but there's no reason anyone else e.g. hobbyists should use such a formality instead of another categorization that provides more data. It is useful to know that Laelias can breed with other Cattleyas, and it is also useful to know that Laelias have characteristics that distinguish them from other Cattleyas. Both the lumping and splitting have merit if only we could get over the idea that everything has to fit into that box.

I'd be curious to know the average age of all the commenters on this thread, given the resistance to science and making it seem like finding cultural info was ever about the genus when it should always be about the species.

I'm an old poop... probably one of the oldest of the commenters on the Board (not going to give a number though) I accept the science - knowing that it's not cast in concrete. Science gets refined and therefore there is no reason to believe that there will be no more changes. While I agree that one generally needs to get down to the species level to really make any sense about culture, there are some situations where one can "know something" about a plant at the genus level, and lumping does detract. Example... when I buy a Sophronitis, I have a pretty good idea of the culture for most of the species within that grouping. Calling them Cattleya not so much. Then I DO need to get to the species level to make any sense of the culture (or for that matter, whether I have room for it in my yard.) A Phalaenopsis in the traditional sense is another one... There are some small variations on the cultural theme, but in general, say "Phalaenopsis" and one has a pretty good idea how to take care of it, even if it is NOID grocery store hybrid. Throw Hygrochilus parishii (Phal. hygrochilus) and Sedirea jaonica (Phal. japonica) into the mix, totally different,. Of course, changing tags on thousands of plants in a collection isn't going to happen, keeps the mind young maintaining a mental cross reference. Which is not a reason to not follow the science, but does cause some angst.

So why not take it further, using your example as a reference? Phalaenopsis also had Doritis lumped into it, and the care is quite different . . . or how about things that have been Phalaenopsis for a while, like the different sections within the genus (Polychilos and Aphllyae stand out as needing very different care).

The argument is basically moot, because the plant before you is the plant before you, regardless of the name that was given to it by humans, either 10 or 100 years ago. Hearing people him and haw about the ever-changing scientific classification feels performative and exhausting.

People who dedicate their LIVES to biology and genetic research and the institutions forking over the funding to support their knowledge and findings is what we could be talking about. Cataloging life in the dire times we live in should be one of the most important things we are all doing and celebrating.

Just keep in mind that the cataloging process is imperfect too. The decision about how much difference in the DNA makes a different species - or different genus - is a human decision. Nature doesn't care. Hybrid swarms also muddy the water. (Example, for the European Mediterranean-zone terrestrials, the taxonomy is a hot mess. Same for the Central American Sobralias. Put a name on it, and you likely still don't know what it REALLY is)

I think the issue that I see with a statement like this is that it completely misrepresents the great strides that molecular biology has made and the increasing level of sophistication and diverse ways that are employed to help understand our natural world better. Some of the reorganizations and changes that have occurred in plant systematics and taxonomy are not "just" about DNA or the orchids themselves they are taking into account how these organisms fit into and enhance our whole understanding of plant evolution, ecology, geology, climate and the interplay between these large concepts. Sometime in the 90s as molecular biology techniques became available we had another tool we could overlay and help us understand "species" which is a debate in that of itself, especially with plants but again, misrepresented here.

In many cases hybrid swarms actually INCREASE our understanding of plants, not decrease. They represent very closely related forms and there can be a lot of different implications based on the study of natural hybrid swarms. To an ecologist this can be an important area of study and the underlying molecular data (molecular clocks, sequencing) can tell us important ecological relationships, past climate and even geological changes. This is a poor argument to criticize taxonomic changes.

It's also a bit of a red herring to point to a group of orchids that is poorly understood, and largely poorly represented in many hobbyists collections like Sobralias. The same can be said about Mediterranean terrestrials. I think we all know why these sections in the extremely diverse family that is Orchidaceae aren't sorted out- it just hasn't had the attention and resources put to it. Again, another poor argument. Cattleya, Vanda and Phaleanopsis are genus that have a lot more research behind them.

For example the changes to Cattleya actually make a lot of sense. They represent a genus that has significant diversity in forms and has expanded into a huge variety of ecological niches in a particular geographic area but in the end these forms readily interbreed and are less genetically distinct than we would believe if we were just using our eyes and a few basic tests to organize them. The changes were made not just by arbitrary personal opinion but by weighing multiple factors, which I have described above and certainly not in a vacuum... as if these taxonomists are just looking at a screen of single nucleotides.

If you are going to distill everything you said down to : "do we really know anything about anything" I would agree with the statement but not the implication. Its another hand waving rhetorical question that is akin to a stoned hippie asking "is reality even real?". There is no conspiracy here...there is very little money for academics in this space these people are largely helping through a labor of love to contribute the better understanding of our natural world and the labor of re-writing tags or challenging our porous memories weighs little on their minds.

If we take your position to the Nth degree, then every single plant would be a separate species.

The problem is that we are going from 18th & 19th century evaluation of measurables, to the infinite depth of analysis of DNA, and then still trying to apply human defined definitions (IE, where to draw the lines between 'genera', which are a human construct).

If we apply your point of view as to how easily the plants can breed (partially based on number of chromosomes), then we should lump broughtonia, encyclia, epidendrum, prosthechea, etc. into Cattleya also.

I have really failed to make my point if all you took from my post that the only reason for changes in Cattleya is due to the ability to interbreed. Again, believe it or not, the research sphere around Cattleya taxonomy even considered horticulturalists when they attempted to deal with taxonomic issues posed by:

Cattleya maxima and Cattleya araguansis

Brazillian Laelias

How do we deal with Sophronitis?

Ecological and geographical considerations across South and Central America

I just took one example.

Anyway, you keep missing the point that both the old and the current taxonomic distinctions are human creations (the plants don't give a damn). But, it is not something that can be codified with 100% certainty (like the periodic table).

We can keep moving the lines back and forth, but they remain rigid human constructs applied to a fluid world. There is no right or wrong in any of this, simply artificial constructs imposed on nature. As is common in such cases, some will agree, while others disagree and yet others simply ignore the debates.

Finally, while DNA represents the current level of definition, who knows what other identifiers we will discover down the road if we look even deeper into the organisms?

I think one of the problems is that it seems like the instinctual response taxonomists have when discovering one genus deeply nested in another (eg Sophronitis being nested in Cattleya) is to lump in order to maintain monophyly. But usually monophyly can also be maintained by just splitting further and make new genera, which is what I would personally prefer in many cases. For instance you can keep Sophronitis by splitting genera at the places I marked here.

I reckon erecting several new genera is probably more work for taxonomists than just lumping one genus however, so I suspect lumping is often chosen instead due to convenience.

A major point. Interpretation of any studies remains a human decision or choice. Those are always debatable.

Furthermore, we are just beginning to sequence, examine and understand DNA. Sweeping taxonomic changes have been made after studying fewer than 200 base pairs on one chromosome. I think that's somewhere between ignorance and arrogance.

I wouldn't call it arrogance. Whole genome sequencing takes a while and is really expensive, which is why researchers typically just select one or a few DNA regions to sequence.

Its not like DNA regions are chosen at random either. Many are inconvenient to study because they are hard to detect in a DNA sample or are too large, and others are just not worth studying since they barely vary between species.