Any Prunus experts reading: Slightly mysterious plums

So, I took on an allotment in 2013.  The neighbouring plot has three mature plum trees, with a weeping habit, which bear very fragrant, sweet golden plums each autumn.

Those plum trees used to be at the edge of a thicket between our plots, which had become overgrown when the previous allotments committee was incapacitated due to illness.   That thicket was cleared about 5 years ago, so a wheelchair accessible plot & composting toilet installed.

I realised at that point that I still had three young Prunus trees on my plot, beside my shed.  I wasn't optimistic, I assumed they would be rootstock suckers.  But I also like bullaces, which I think is basically what St Julian A rootstock would fruit?  So I let them grow, and they also have a weeping habit, and flower, and finally last year set fruit.  They seem to be very much the same fragrant, sweet golden fruit as my neighbour gets.  

So I have a bit of a mystery ... I've no idea what variety of plum this might be, and as far as I know, it's either grown from a fruit but still a good fruiter (there's a Victoria plum on the next plot about 50 m away) or the parent was an own-rootstock and this is a true sucker, or ... ?  Helpful suggestions on a postcard, as we used to say ... Thank you in advance.

(The golden raspberries in this photo are an autumn (primocane) fruiting variety - nice flavour, the canes were an intentional gift from a neighbouring plot-holder who wasn't sure if they are 'Autumn Gold' or some other variety).

I intended to mention ... it's possible that the parent of all these extant trees was cleared away when the thicket was cleared.  The trees on my neighbour's plot are more mature than mine, so probably 15+ years old, I think out of memory of origin of any current plot-holders.

You seem to know more about plums than me, so take my words with a grain of salt.

It seems possible they grew from a fallen fruit. I don't believe plums grow very close to their parents when grown from seed, so wouldn't that open the door to it being a unique variety?

Some mirabelle plums have that colouration so it might be one of them. When I bought my current house two old plum trees, (a greengage and some form of smallish purple plum) had self seeded all over the place, the pollen donor appeared to be a yellow mirabelle that I also have, as every seedling tree produced small yellow Terrible tasting fruit, which is a bit odd as all three parents taste fine! They were also very thorny and again none of the possible parents have thorns, so I would think that your trees are probably not seedlings, but could be suckers if they are on own roots.

One suggestion from a friend who knows more about fruit trees than I, is that these are effectively a 'yellow bullace' but the fruit is improved by the Victoria plum as a pollinator on another neighbouring plot?

Ac Baker wrote:One suggestion from a friend who knows more about fruit trees than I, is that these are effectively a 'yellow bullace' but the fruit is improved by the Victoria plum as a pollinator on another neighbouring plot?

Am I reading this correctly? I'm hearing that the pollen source is affecting the flavour of the resulting fruit.

I found a couple of plum varieties that look similar, but since your trees seem to be growing on their own rootstock, it is probably a unique variety, lucky you!

Prunus domestica ssp.syriaca 'MIRABELLE de NANCY': cherry plum, so fruit is likely to be smaller than standard plums.

Prunus domestica  'REINE CLAUDE DORÉE' golden gage; a sort of green gage.

Prunus salicina 'GOLDEN JAPAN', japanese plum. these should ripen earlier though.

The roundness and red mottling is distinctive.

Thank you, Nancy! So the main theories seem to be: This is a seedling, with a very lucky combination of being happy on own rootstock, a large plum size fruit & excellent flavour; or a yellow 'bullace' but the fruit is enhanced in size by a Victoria plum pollination partner; or that it's some unknown golden Prunus which tends to come true from fruit?

I do not know enough about Prunus to really say which if any theory is correct.

e.g. Maybe the red mottling is from Victoria plum pollination?

I will ask some of the more experience plot-holders for their input too.

I get a lot of volunteer plum trees and my experience is some of them are from disturbed roots  sending up a new trunk and some are crosses from seed. Occasionally one will have undesirable fruit but often they are enhanced seedlings benefiting from the difference in the parentage. For example some of the crosses between the green gauge and a yellow plum are sweeter than the yellow plum but still free stone like the yellow plum.  If I decide to move a tree because it is too closes or in a path and the root is connected to another tree the I know it is a clone but I do not worry about names, just accept wat is good and chop what is less desirable.

Michael Helmersson wrote:Am I reading this correctly? I'm hearing that the pollen source is affecting the flavour of the resulting fruit.

Good point. The pollen donor of this year's fruit doesn't affect the flavor or color of the fruit. Pollen would only be an issue if you knew that this tree was from a dropped fruit from a known tree and were wondering about the other parent of this tree.

Ac Baker wrote:Thank you, Nancy! So the main theories seem to be: This is a seedling, with a very lucky combination of being happy on own rootstock, a large plum size fruit & excellent flavour; or a yellow 'bullace' but the fruit is enhanced in size by a Victoria plum pollination partner; or that it's some unknown golden Prunus which tends to come true from fruit?

I do not know enough about Prunus to really say which if any theory is correct.

e.g. Maybe the red mottling is from Victoria plum pollination?

I will ask some of the more experience plot-holders for their input too.

Pollination only affects the genetics of the seed/kernel on the inside, and you would only see the results of those genetic/cross-pollination if you grew a tree from the seed to the point that it would give fruit. Not sure what the exact size of these plums are but they look a lot like some form of gage or mirabelle. I think they might be a bit too big to be mirabelles? Looks a lot similar to Reine Claude Dorée otherwise which are in the gage/greengage family, but these also look similar to true mirabelles like Mirabelle de Nancy..