Blue Wood Aster/Heart-leaved Aster (Symphyotrichum cordifolium) 'Avondale' 2015-9-3 Newark Oaks, DE

from Mt. Cuba Center
syn. S. cordifolius 'Avondale'
http://www.mtcubacenter.org/plant-finder/details/symphyotrichum-cordifolium-avondale/
http://www.nps.gov/plants/pubs/chesapeake/plant/267.htm
https://www.wildflower.org/gallery/species.php?id_plant=SYCO4
-1-5 feet - native - flowers August to Oct blue-purple, sometimes so pale it's almost white, disk flowers begin yellow and change to red - mostly found in partial to full shade
-not to be confused with:
-Symphyotrichum undulatum - S. undulatum middle and upper leaves widen near and clasp the stem where S. cordifolium middle and upper leaves are narrow or stalked at the base and don't clasp the stem.