Ploidy differences of northern vs southern “Diospyros virginiana” are a well known and accepted occurrence. These two populations, based on my understanding, are incapable of breeding with one another, amongst other distinctive traits such as cold hardiness and growth habit.
What is confusing to me is that we as a community of fruit enthusiasts still discuss these distinct populations as if they are one species.
Generally speaking, "A species is often defined as a group of organisms that can reproduce naturally with one another and create fertile offspring. While that definition seems straightforward, the classification of a species can be difficult and at times riddled with controversy. "
It is my opinion that a new species name should be proposed for southern" Diospyros virginiana".
Based on location and existing Latin naming systems, I’d say Diospyros floridus would be appropriate, acknowledging a more commonly used name based on southern states.
I’d be surprised if anyone has an argument for keeping them in the same ‘species bucket’, and frankly, I’m surprised this hasn’t been changed yet. Everyone discusses northern and southern persimmons as distinct and separate groups but I don’t think I’ve seen mention of actually separating them by species.
Which international body should be approached to make a change? I think these days it might be Facebook.
Here’s are a few necessary steps which come to mind quickly:
*First determine which of the two types was the original one which was described when the species name was published. This is the one that gets to keep the older name.
*Collect an herbarium sample for the “new” species to have catalogued at a major institution.
*Publish a formal species description which is rigorous enough to pass scrutiny from experts in the field. If the majority are convinced of the validity of your species claim then it will come into use. If not… not.
I am sure a lot of people in the slightly more northern south… like me here in southern TN dont really know whether they have 90c or 60c persimmons.
The KY State is said to have a mix of both.
Does that continue into Southern TN ?
What about North/South Carolina, Virginia ?
Now that i have 7 and soon to be a dozen or more 90c varieties started here… i suppose I will know if my native trees are 90 or 60 depending on if i have seeded fruit or not.
Hoping for seedless
It is true right that if my native wild males are 60c… then all these 90c americans i have started here should be seedless ?
I expexct that all the hybrids I have were crossed with 90c persimmons… and would not produce seeds with only 60c males present.
There are different definitions of what a species is, traditionally interbreeding was the main characteristic, but that definition has various issues such as ring species and micro species, to say nothing of very distant hybrids, even intergeneric hybrids. Other definitions are based on sets of shared characteristics, on populations, on things like the least common clade (ie smallest taxonomic group you can reasonably make), etc. my personal favorite is the “cynical species” concept: a species is whatever the most famous biologist studying it says it is.
No one definition of species satisfies all the parameters, so you basically just have to pick one based on the occasion and your background. I’ve noticed, for example, that Chinese biologists seem to be very generous with the species label, hence why you can have dozens of different species of rhododendron in southern China that differ in minor leaf or flower morphology and on which particular mountains they grow on.
That’s the thing, a ‘species’ IS a fluid term up for interpretation by humans. Many species have changed over the years.
Viburnum trilobum is apparently now considered Viburnum opulus, just the ‘American variety’. I haven’t researched that one to see how compatible they are for reproduction,ploidy, etc.
If DV is incompatible reproductively, in nature, due to ploidy and whatever other factors exist, I see that as a strong argument.
I’d be curious to see if they are genetically distinct ‘species’ or not…
Even that argument is going to have a certain amount of variation within ‘species’, so who gets to draw the line?
90C and 60C are very similar with overlapping territories. It would be more appropriate to use a subspecies name. For example, Diospyros Virginiana floridanus would be one way to maintain relationships while differentiating subspecies. Hickory (Carya species) uses this approach with shagbark hickory (Carya Ovata) which has a recognized subspecies australis.
TNhunter, you have 60C persimmon. Height is a dead giveaway. 60C is significantly larger and grows faster. However, you may still see some seed if any of your female plants happen to produce a few male flowers. I can’t entirely rule out a hybrid between 60 and 90 if ploidy levels change. For example, a persimmon is known with 8 sets of chromosomes.
Are the delayed graft compatibilities between 60 and 90 DV? I know there’s a couple with Kaki. I got a bunch of seeds from a local tree and don’t want half the trees to die just when they get good.
When you look at the number of outdated synonyms for Diospyros virginiana it seems pretty likely that at least some of those many synonyms must have been attempts to break the species down into smaller categories in the past, but were not accepted by a consensus of experts.
On that note, if the southern population were to be recognized as validly deserving of separate species status then the oldest pre-existing publication in which it was named would take precidence and so assigning a new name such as Diospyros floridus would not be possible.
There are a bazillion white oak species (or is it a Brazilian?) that are capable of hybridizing and do all the time. In line with oaks (and other tree species), I agree that the 60C and 90C should be separated.
I have seedlings growing from 2 sources. I suspect one is 90c and the other is 60c. The Lee Reich method below of distinguishing the two seems to work for my seedlings.
Additionally, hearing from one forum member who has used 90c and 60c for many years, both make a good rootstock. Both have occasional unexplained incompatibility
I almost brought up oaks in my earlier comment. It’s such a mess, lol.
But I think I can do one better. How about Diospyrus virginiana and D. kali? Sure, they can’t cross naturally, but now we have intermediate taxons that can cross with both such as Nikita’s Gift and related cultivars. So D. v and D. kaki are now technically the same species, though a ring species where only taxons in the middle can cross with the ends, but still.
Yeah, interbreeding is not a perfect criteria, not by a long shot.
I’m not being super serious with this example, but the effect is a real thing: see coyotes and red wolves.
Edit: I’ll explicate this example because it’s a really interesting one.
Historically, coyotes lived mostly out west and did not interbreed with the red wolves here in the southeast. After grey wolves were killed off, however, coyotes began expanding their range eastwards, and picked up some domestic canine genes on the way. The resulting population were physically bigger, had learned pack hunting behavior, and preyed on larger game, including deer, unlike the coyotes still out west. The (disputed) eastern coyote (sub?) species can and does interbreed with red wolves, much to the detriment of the remaining wild red wolves (all twelve of them or whatever is left).
Whether or not two individuals can reproduce with each other doesn’t work for defining species. Consider how some species resist fertilization from close relatives.
