Butterfly Milkweed or Butterfly Weed [Asclepias tuberosa] found near Fletcher Park on 28 August 2013 and 18 June 2016. It’s a member of the Milkweed (Asclepiadaceae) family. Newcomb’s Wildflower Guide, pages 188-189, states it blooms in summer in dry fields and on banks, and it also lists another common name as Pleurisy Root.
USDA Plants Listing: Asclepias tuberosa