Scientific NameCentaurea cyanus
Other Common Names:
Synonyms (former Scientific Names):
Erect winter annual that grows to 1.2 m tall with a taproot and often a weed in small grains.
Leaves are alternate approximately 5 to 15 cm long and 1 cm wide, lance shaped to linear, hairy, and has entire or slightly toothed margins. Due to the leaf appearance, these plants are often confused for a grass.
An erect winter annual with long white hairs and blue, white, or pink flowers. Plants may reach 3.5 feet in height.This weed is sometimes confused with both Spotted Knapweed (Centaurea maculosa) and corn cockle (Agrostemma githago). However, spotted knapweed forms a basal rosette of leaves during the first year of growth and its leaves are much more deeply lobed than those of cornflower. Additionally, the leaves of corn cockle are joined across the stem and the stems of this plant are swollen at the nodes whereas neither of these characteristics occurs with spotted knapweed or cornflower.
Flower Seed Head
Many solitary heads are produced on long flower stalks (peduncles). Flowers are 2.5 to 5 cm wide and 1.5 to 3 cm long.They are pink, purple, white, and sometimes blue in color.
The seed is an achene that is about 4 mm long and 2 mm wide, and is gray in the middle and yellow brown on the ends with pubescense on one end.
Found throughout the eastern half of the United States and also in the western states from California to Washington.
upright and nonwoody
Thorns or Spines
Approximate Flower Diameter
Dominant Flower Color
Stem Cross Section
round or oval