Nodding Plumeless Thistle[Carduus nutans] near the railroad tracks on Old Airport Road in Fletcher, North Carolina on 16 June 2013 and 25 May 2015. It’s a member of the Aster (Asteraceae) family. Newcomb’s Wildflower Guide, pages 430-431, says blooms in summer and fall, and that it grows on roadsides and in waste places.
USDA Plants Listing: Carduus nutans