I'm not really sure what it means to have opposite foliage. I know very little about plants and whatnot. We just moved to this agricultural region from a city region and all of this is new to us.
I'll try and get a picture of the whole plant tomorrow. Are there Dogwood species that have bluish colored berries? Googling has been fruitless (HAH) because the search terms inevitably bring up blueberries. I doubt that's what they are, though it would be nice.
Opposite foliage means that the points of attachment of leaves along the stem of the plant are opposite each other, making the leaves look like they occur in pairs.
This term is in contrast to alternate arrangement of leaves, where the point of leaf attachment occurs singly and the leaves appear to alternate along the stem.
Some common plants you may recognize: Maple has opposite leaf arrangement; Oak has alternate leaf arrangement.
Urban versus rural/agricultural doesn't matter to plants - they don't discriminate amongst their stewards. And you have found a pretty sweet place to land - Penn Yan is right in the midst of a bunch of alternately arranged Vitis vinifera. I've sipped a few flavors from the Keuka Lake bounty.