To be completely honest, I'm not sure as to whether this is a bush or a tree. The ones I've seen are about 3 feet tall and under. The leaves seem to be opposite sides on the branches and are roughly one inch long each. They (the leaves) aren't usually wider than 1/2 an inch.. And it produces small berries that, when ripe, are a dark blue/purple color. So far (all the plants I've encountered are only a few years old...) the bark is smooth and gray.

Does anyone have an idea? I've wondered about these bushes/trees for years.

Any suggestions would be quite appreciated. Thank you.

Try looking up Beauty Berry. If it is birds love the berries, they also make good jelly.