The flower is a native phlox, probably either Phlox paniculata (summer or garden phlox) or Phlox maculata (meadow phlox).  Both can bloom this time of year.  For more specifics, "Native Plants for Wildlife Habitat and Conservation Landscaping: Chesapeake Bay Watershed" is a great publication, now available online.  It has a wealth of info, plus color photos, on all categories of native plants in this region.

 The small tree looks like the leaves and samara of a hop tree (Ptelea trifoliata).  

ECN

Thanks very much for your response.  I eventually figured out the phlox (needed to look elsewhere than under "wildflowers").  But the hop tree was still a mystery to me.  I appreciate your help. -- Joe Bartl