We have what I think may be a wild plum in our back yard. The fruits are roughly the size of an olive and very dark bluish-purple. I love this tree, it's been good to us. However, I think it needs a good trim. We cannot reach the upper fruits, even with a ladder. It has become spindly and has daed branches. I need to mention that it is planted between pines and an oak tree. It is also next to our compost heap.