Centaurea nigrescens Willd.
Family: Asteraceae
Tyrol knapweed, Vochin knapweed
Centaurea nigrescens image
from USDA Plants website  
Etymology: Centaurea: ancient Greek plant-name, poetically associated with Chiron, the Centaur, but without wholly satisfactory explanation
Plants: perennial forb
Conservation Status: Introduced - adventive