Velvet, if Satsuma is ripened a long time on the tree they look about black. The main way to tell its not Satsuma is not by the color but by the size, they are more like ping pong ball sized which is a bit smaller than the standard modern grocery store plum. Scott

Thanks everyone for your replies. Unfortunately I don't have a photo of the fruit. The last few years it did develop a fungus (which I think is called plum pocket). You can see a withered plum in the second picture. Before that though, the fruit was always good and sweet. theaceofspades: you may be right about it being planted from a pit. That sounds like something that my grandfather, whose property it was, would have done. destin_gardener: It didn't have any thorns. From my online reading, I think that yes, it is likely a Canada or American plum. It was really a hearty tree for being so far north, so I think a native tree is probably a good guess. Thanks again. And if anyone has an idea, please chime in!

Fatamorgana,thanks for that link,i finally found the kind of plum tree i have,mine is the "Yellow Shiro Plum"a japanese plum.I've had mine close to 30 years or so.A friend i used to work with had one in her yard and she gave a couple of us,starts from her tree.I'm the only one who still has it,and that thing is sooooooooooo loaded,that the limbs are bending. The rest of my friends killed theirs with kindness,but i share my plums with them.LOL,LOL They are the best plums i ever ate,and they should be ready to eat in a couple more weeks.Sometimes i just grab a few off the tree,wipe it off on my shirt tails and eat. The other thing i like about these is that no critters or birds bother them,like they do my peaches.The birds come along the peach tree and take a bite of a peach then move onto another,makes me so angry.Told dh we need to get one of those nets fr the tree,before they eat them all. Kathi

I think the damages on the leave look like the work of worms/caterpillars. Many work during the night. If you go out with a flashlight, you may catch them in action. Hope you compare those bugs with pictures of ladybug's stages. Floral is probably right.