Mulberry trees, actually. Very big trees in fact. We have two of them in our back yard, and they mark the border where our trimmed yard ends and our scrub "back of beyond" begins. I'll take pictures of them for you, but they are definitely some of the biggest trees on our property.
I never knew what type of tree they were until a couple of years ago. Then after I found out what they were, I thought maybe something was wrong with them. Most of the berries I saw dropped off the trees and were white. I figured that they never really got to "full ripeness" and fell off early, so just never paid much attention to them. Then I looked them up last year and guess what! They are supposed to be white! And we can eat them! So I ate a few last year, and picked just enough to throw in a pie.