I'm trying to figure out what the red-stemmed plant in the picture is. I have a smaller one in my flower garden, probably planted by the previous owner, and the leaves are much greener. The ones in the picture are growing on the slope of a pile of landscaping rubble near Chicago, along with lots of coneflowers, poplar trees and willows.
The red stems are not woody like most bushes or trees, the leaves are a dark green, the cone shaped flower pods have lots of small white flowers that become small, black berries. There don't seem to be a lot of roots, rather a large whitish main root that may connect several plants.
I've searched for hours on the 'net with no luck. Any ideas are greatly appreciated!