Acosta
diffusa or Centaurea diffusa
(Diffuse Knapweed)
Family:
Asteraceae (Sunflower)
Noxious Weed!
Diffuse knapweed is a biennial
weed. Flowers are usually white but are sometimes lavendar. Bracts below the flowers
are reflexed and have bristles along the margins. Stems divide into many branches,
giving mature plants a shrublike structure. Diffuse knapweed is a noxious weed
that should be aggressively controlled.