After about three years of watching, I finally located a berry. But it has over-wintered and is wrinkled, small, and very much out of reach. I estimate the size to be that of a pencil eraser, but I can't be sure, because it's so high.
The tree itself spreads out beautifully! Nicer than an apple or cherry, for instance. It has leaves and blossoms like those fruit trees, although the blossoms are not very pink. And the darned thing is covered with very long, hard thorns. Much nastier than even a rose thorn.
The branches tangle just like the fruit trees, but the fruit is just a tiny berry. What's more, they are gone long before they are even ripe, so I can't tell you what color they are.
It's bark is heavily grooved, and of course the tree itself is gnarled.
Can anyone give me a link to check on this thing?