Weed
bighead knapweeed
AcheneAchene:
A dry, hard, one-chambered, one-seeded indehiscent fruit, as in buckwheat (Fagopyrum) or sunflower (Helianthus). The fruit wall is not united with the seed coat.
ObovateObovate:
Inverted egg shaped with apical end the broadest.
Brown with a yellow base and longitudinal lines
Smooth
Thick, bristly, and brown pappusPappus:
Modified calyx in Asteraceae, composed of hairs, bristles, awns, or scales. The pappus-like structure attached to milkweed seeds is termed a coma. 
; lateral scar at the base.
AcheneAchene:
A dry, hard, one-chambered, one-seeded indehiscent fruit, as in buckwheat (Fagopyrum) or sunflower (Helianthus). The fruit wall is not united with the seed coat. has a narrow base and widens toward the brown apicalApical:
The distal end of the fruit or seed away from the point of attachment or attachment scar.
collar.
State Noxious Weed: Arizona, Washington
Not included
Asteraceae
Centaurea macrocephala Puschk. ex Willd.
