Centaurea cyanus

Species category

Flower

Common name

garden cornflower

Diagnostic characters

Planting unit

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.

Shape

Oblong

Size

  • Length: 4 mm
  • Width: 2mm
  • Thickness: 1.5 mm

Color

Blue-gray with yellow longitudinal lines, collar, and base

Texture

Smooth

Other structures

PappusPappus:
Modified calyx in Asteraceae, composed of hairs, bristles, awns, or scales. The pappus-like structure attached to milkweed seeds is termed a coma. 
with dense bristles; scar slightly oblique and large.

Identification notes

AchenesAchene:
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.
oblong, compressed; smooth, glossy, sparsely pubescentPubescent:
Having hairs.
, blue-gray with various amounts of light longitudinal lines, area around scar yellow. ApicalApical:
The distal end of the fruit or seed away from the point of attachment or attachment scar.
rim white to yellow, horizontal. PappusPappus:
Modified calyx in Asteraceae, composed of hairs, bristles, awns, or scales. The pappus-like structure attached to milkweed seeds is termed a coma. 
of dense narrow scales, brush-like, uneven, erect, tan to reddish-brown, persistent. Scar laterally-oblique, opening one-third the length of the 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.
.

Noxious weed seed categories

State Noxious Weed: Arizona, North Carolina 

AOSA examination list

Included

More information

For more information, see ISMA fact sheet.

Nomenclature

Family

Asteraceae

Valid name

Centaurea cyanus L.

Synonyms

Leucacantha cyanus (L.) Nieuwl. & Lunell

 Centaurea cyanus . Achenes are blue-gray with yellow longitudinal lines, a collar, and a base.
Centaurea cyanus. Achenes are blue-gray with yellow longitudinal lines, a collar, and a base.
 Centaurea cyanus . Achenes with dense bristles and a slightly oblique, large scar.
Centaurea cyanus. Achenes with dense bristles and a slightly oblique, large scar.