Identifying plum species (not variety)

Are there any strong identifying traits that allow one to differentiate the major plum species? European, Japanese/hybrids, and prunus Americana?
I am referring to bark,leaf, and bloom not fruit.

With everything in bloom right now, I found a small patch “feral” plum hiding in a neighbors wood lot. They are clearly growing up along the edge of an old long abandoned homestead. The cellar holes and lillies gone wild are a dead giveaway.

The trees themselves are all fairly small at 6" diameter or less and maybe 10’ height and I am assuming they are either root suckers or seedlings. Of some long gone original tree.
They appear to be black knot resistant/immune as they are mixed among many wild choke cherry and black cherry simply covered in knots while the plums have none. Unfortunately the forest has mostly reclaimed the area, they are definitely becoming shaded out by full size trees and overgrown by grapes.

Feral plums are pretty uncommon around us, I have only found a few others ever and I spend a lot of time in the wood and field.
So these have me very curious. I will revisit at harvest and see if I can sample fruit, but in the meantime I am wondering if I can at least categorize their type roughly?

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There are several plum species native to north America, including these:

Species Records of Prunus sect. Prunocerasus

Prunus americana Marshall (subg. Prunus sect. Prunocerasus)
Prunus angustifolia Marshall (subg. Prunus sect. Prunocerasus)
Prunus geniculata R. M. Harper (subg. Prunus sect. Prunocerasus)
Prunus gracilis Engelm. & A. Gray (subg. Prunus sect. Prunocerasus)
Prunus hortulana L. H. Bailey (subg. Prunus sect. Prunocerasus)
Prunus maritima Marshall (subg. Prunus sect. Prunocerasus)
Prunus mexicana S. Watson (subg. Prunus sect. Prunocerasus)
Prunus murrayana E. J. Palmer (subg. Prunus sect. Prunocerasus)
Prunus nigra Aiton (subg. Prunus sect. Prunocerasus)
Prunus ×orthosepala Koehne (subg. Prunus sect. Prunocerasus)
[= P. americana × P. angustifolia; valid publication verified from original literature]
Prunus rivularis Scheele (subg. Prunus sect. Prunocerasus)
Prunus subcordata Benth. (subg. Prunus sect. Prunocerasus)
Prunus umbellata Elliott (subg. Prunus sect. Prunocerasus)

Yes, I knew someone would bring that up, and it does complicate things some.

But in likelihood since there are nearly no native plums in my area, and it’s growing along an old farmstead; it is a cultivated variety, seedling thereof, or suckering rootstock…or I suppose seedlings of a suckering rootstock.

What I was asking is if there are morphological features that might give an indication of their type.

If we change the word “type” to “subgenus” and “section” then yes. I’m no expert in this – three of them I usually can spot out of the crowd. But I suspect there are others here or at the GRIN Prunus sites who could help you. Here’s the breakdown.
Subdivisions of genus Prunus:

Subgenus, Section (if any)
Cerasus, Cerasus
Cerasus, Laurocerasus
Prunus, Armeniaca
Prunus, Microcerasus
Prunus, Penarmeniaca
Prunus, Prunocerasus
Prunus, Prunus

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I certainly don’t think I can directly help either, but I wonder if you should really be ruling out wild plums. I’m out in the woods a fair bit, too, but I’ve only once found a colony of wild plums.

(I was bummed to see it was just bulldozed within the last month. I was meaning to knock at the nearest house, ask if it belonged to them, and see if I could dig up a sucker. I guess I could have dug up the hole colony. The colony was right by one of those little 3’ towers/cases that the telephone company has beside the road, so I think one stem may have survived the bulldozer thanks to that obstacle.)

My point is simply that some species that grow wild seem to be very uncommon. For comparison, I’ve heard that pawpaws grow wild in every county in North Carolina, and I’ve spent a good bit of time int he woods in a few different parts of the state, but I’ve only once found pawpaws in the wild. Other people have shown me other wild trees/groves, but I’ve only once found any pawpaws myself. It seems like wild plums might be similarly uncommon even though they’re native.

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Agreed that I cannot rule out native plums, as you are right that some native plants can be very patchy with just a few colonies in any given area.

But I am fairly confident that these guys are related to the farm that once stood at the site. Also their growth habit is nothing like the few stands of wild plum I have found in neighboring towns. Those form dense thickets, with youngest stuff along edges. These are much more open mostly the same age, and more tree like than bush like. But that could be a response to the forest reclaiming the open space.

Also bloom time on these is identical to our own hybrids, the wild ones I know are a few weeks later (relative to apples around each)

I always forget that location and zone don’t show here on this forum.
The selection of possible/likely native plums is fairly limited here in northern vt. I think Americana and possibly nigra?

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If so, why?

I would assume climate, soils, and regional competition. I should perhaps narrow my geography to northern mountainous vermont as I am not as familiar with habitat down toward the lake.
And I could be mistaken. I am the one here asking for information on species with which I have little familiarity.

Here are some of the Prunus species that are or once were native to your area of Vermont:

“American Red Plum” Prunus americana

“Bird Cherry” Prunus pensylvanica

“Bitter-Berry” Prunus virginiana var. virginiana

“Black Cherry” Prunus serotina var. serotina

“Canadian Plum” Prunus nigra

“Susquehanae Cherry” Prunus pumila var. susquehanae

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Thanks Richard,
I am quite familiar with all of the native cherry in our area that are members of the genus prunus
All of my questions regarding differentiation have been directed toward those species commonly referred to as plums…such as the Americana and Nigra
As well as the non-native european plum, prunus domestica and asian plums, prunus salicina

The P. americana and P. nigra are the only ones in your area with what is regarded as plum size fruit.

In terms of non-native species with plum size fruit under cultivation for centuries that would grow in your climate, there are two from western Europe, another that originated in Turkministan, one from Africa, two from China, and two from Japan.

The folks at the Davis ARS/GRIN repository probably have field notes on all of them.

I’m not sure if this will help,but after reading your question,I checked one of my trees.There are four Plum varieties,Shiro,Santa Rosa,Blue Damson and Italian Prune growing on this multi-graft.
One of the major things noticed was the two European ones,the Damson and Italian had leaves that were somewhat “fuzzy” to the touch,while the Japanese were more smooth and slicker.The Damson’s leaves were a little shorter and rounder,not so elongated compared to the others. Brady

Thanks Brady,
If those types of traits are reasonably consistent, that is exactly the sort indicators I am asking about.

I was just going to say the same thing as @Bradybb --judging from my little experience, Japanese plum leaves are smoother, esp when young, whereas the Euro plum leaves are not only fuzzier, but have more of an indent pattern on them along the veins, more like alligator skin. More texture in general. Euro leaves also seem shorter and fatter, and seem to have more red on them when young, but again this is based on a very small sample.

FWIW…based on my limited knowledge on the subject and limited sample plums, both Brady and Lizzy’s descriptions fall in line with my own observations.

Here is a photo of 2 native plum species here in central Illinois . On the left Prunus Angustifolia and on the left Prunus Americana . Plus a seed of Americana that is mostly round and flat . I hope that this helps you identify what you have . The trees look alike when dormant . Size and shape of the trees are the same . Both sucker freely to form a thicket . Both have thorns when young . There is a goose plum that is a mix of the 2 but I forget the species name . I doubt there is much difference from P. Nigra and P. Mexicana . All five species are locally adapted and probably cross freely when grow near each other .


What did the fruit wind up looking like? I saw prunus Americana demonstrate strong disease tolerance here in Kansas. I saw similar wild stands of p.americana in Missouri around old homesteads and was curious if they were commonly grown in the 1800s.

I do not have any pictures of the fruit . Angustifolia are red with yellow flesh and elongated . Never got back to the other wild stand when fruit was ripe . The ones growing on my property never set fruit . I think they are all clones of 1 tree . Going to graft some over to something else .

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