Connecticut Plants
Black Knapweed (Hardheads)
Centaurea nigra L.
  • Family: aster (Asteraceae)
  • Habitat: fields, roadsides
  • Height: 1-3 feet
  • Flower size: flowerheads 1 to 1-1/2 inches across
  • Flower color: pink
  • Flowering time: July to September
  • Origin: Europe
Centaurea nigra L.
Centaurea nigra L.

The bracts beneath the flowerhead make a good field mark for black knapweed. Note the long, dark fringes.