Philadelphia Fleabane - Erigeron philadelphicus

Also known as the Philadelphia Daisy.

Family: Sunflower Family (Compositae)
Aster Tribe: Astereae
Flowers: Flowerhead has "hundreds of fine filamentlike ray flowers."
Plants: 8-28 inches tall, biennial or short-lived perennial.
Leaves: Spatula-like, clasping.

Identified: by Lynn Fleming and Janet Wallace, and confirmed by consulting Kansas Wildflowers and Grasses at https://www.lib.ksu.edu/wildflower/philadelphia.html.
Photo: Courtesy of S. Peregrine Johnson.