Wavy-leaved aster
(Symphyotrichum undulatum)

Formerly Aster undulatus; aka clasping heart-leaved aster. Flowers are white to pale blue, with 8 to 15 rays. Lower leaves are heart-shaped, with winged petioles broadening to clasp the stem. Upper leaves are stemless. Leaf edges are wavy. To see a guide to local asters, click here. (Asteraceae)