wild plums, by september they'll developed a red and yellow color and I'll collect them for seed

wild plums, by september they'll developed a red and yellow color and I'll collect them for seed. This tree is a 25-30 year old seedling plum, in a small town backyard. all that I can say about it is that the fruit and leaves are typical for prunus americana, and given that hybrid cultivar plums have little pollen, it's very likely pollenated every year by another wild plum in a nearby yard. Seedling plums in a residential setting, in cultivation just like crabapples surely have some mixed bag of genetics, it could have small percentages of P. salicina or P. nigra in it, one hint is that it doesn't sucker profusely like typical americana. But as far as usefulness as a pollinator, and a rootstock, this sort of seedling can basically be called american wild plum, there is the phenomenon of segregation toward the wild phenotype - when you cross some plum with a wild one, you often get seedlings that look just like the wild one.