Plectocephalus americanus (Nutt.) D.Don
Family: Asteraceae
American knapweed, American star-thistle, basket-flower
[Centaurea americana Nutt.]
Plectocephalus americanus image
Botanical Illustration  
Plectocephalus americanus image
from USDA Plants website  
Etymology: Centaurea: ancient Greek plant-name, poetically associated with Chiron, the Centaur, but without wholly satisfactory explanation
Plants: annual forb
Conservation Status: Introduced - adventive
Plectocephalus americanus image
from USDA Plants website  
Plectocephalus americanus image
Plectocephalus americanus image
Plectocephalus americanus image