Symphyotrichum lowrieanum

This species looks very much like S. cordifolium, and some taxonomists do not distinguish them (see NYFA Atlas link below right). The difference, per the Native Plant Trust GoBotany site (https://gobotany.nativeplanttrust.org/species/symphyotrichum/lowrieanum/),  includes that the leaf blades are glabrous, thinly glaucous on the underside, very smooth on the top surface and the upper leaves often have winged petioles. See Botphoto.info for more ID help.