Trying to ID this native plum

I'm sure everyone but me knows which plum this is. It probably grows all over the place. The plums ripen slowly over a month or two and are still ripening. They are probably the only wild plum that still has unripened and currently ripening fruit. I don't think it forms thickets like the low growing Chickasaw plum or whatever the other one is that grows in huge thickets everywhere. I think this one spreads by seed only. It's usually found at the edge of woods and on fence rows. I'd sure like to put a name on it.

pic 2

It does look like Mexican Plum, Prunus mexicana
http://wildflower.org/plants/result.php?id_plant=PRME
but I am not sure, maybe an expert on plums from your area will know better.
Josephine.

Thanks, Josephine. I was leaning toward Mexican plum, but thought it was less widespread than it is. Some old timers call it hog plum, but I do believe hog plum is different.

There are two other trees called Hog Plum, the problem with common names is that people have different names for the same thing, depending on local custom. Here is one Hog plum
http://wildflower.org/plants/result.php?id_plant=PRRI
and here is the other
http://wildflower.org/plants/result.php?id_plant=PRUM
As you can see it can be confusing.

These are all over San Marcos. I think the city plants them everywhere. It looks just like a Mexican Plum. They are very common in the nursery trade, Home Depot, Lowes, etc.

Very very pretty flowers in the spring.

Further confusing the matter is how wildflower.org and many other resources focus mainly on pictures of the blooms instead of the foliage. The blooms all look about the same to me and I have a much easier time identifying certain plants by their overall form and their leaves. I can easily see why so many people nickname various suckering/thicket forming plums "hog plum". Because if you look into just about any thicket of them, you'll see well worn trails made by the wild hogs. The mexican plum doesn't sucker, so calling it a hog plum doesn't happen so much.
I've concluded that the thicket forming low growing wild plum that numbers in the millions just in my area alone is prunus angustifolia (chickasaw plum) rather than prunus rivularis (creek plum) based merely on the fact that the USDA map shows it in my county but does NOT show prunus rivularis in my county. I realize you can't count on all data but surely it would be shown on my county map by now since it's been around so long and so prolifically. If you read various descriptions scattered all over of each one, some say it's too tart to eat but I know for a fact that some of this year's crop was actually not very tart and actually sweet. I guess the only thing left I can do to possibly remove all doubt is examine closeups of the seed after drying out since USDA does have pics of the seed. It's a lot of trouble to go to but I do like to be able to call a plant by the right name without having any doubt.

I think you are most likely right about Prunus angustifolia, I have never seen Mexican plum form thickets, but then, I live in a city, although i go to forests, prairies and preserves to look around as much as possible.

As far as your county being listed on the usda map,or not, take that with a grain of salt. I know of many plants that grow here in the wild and are not listed on usda as growing in Tarrant county. They depend on someone reporting it and providing proof.
The wildflower center also depends on people providing the photographs, and most people like to take pictures of pretty things, so that is the problem.

lol - We know "hog plum" as loquat...

Those do all have different forms in the wild. The more problem I have is that when people grow them in the city (or the city grows around them), they all tend to get shaped into some idealized form.

It is not uncommon to find several Mexican plum trees growing in close proximity. Many of the small branches end with a sharp thorny point. As a child I quickly learned to be careful when sent up into the tree to jump up and down and shake the plums loose so they could be picked up and used for jelly. I know of no other wild plum in the Comanche County area that makes a tree. The fruit of all Mexican plums are not identical. There are two growing on our property under a large live oak. They do not bloom or ripen at exactly the same time and their fruit does not look or taste exactly the same. Mother nature diversifies! Another characteristic is that they bloom at about the same time as your native redbud - perhaps a little later.