Cornflower (Centaurea cyanus) — identification, habitat & look-alikes

Cornflower is an annual grown in U.S. gardens for its bright blue summer flowers. Native to Europe and western Asia, it now grows wild in fields and along roadsides across much of the country. It is also called bachelor’s button.

Appearance

Growth form: An annual or winter annual, usually 8–39 in (20–100 cm) tall, with a single main stem that branches near the top. Grayish hairs give the plant a silvery-green look.
Leaves: Narrow leaves with smooth edges.
Flowers: Flower heads about 1 in (2.5 cm) or more across, most often a vivid blue but sometimes purple, pink, red, or white. The small green leaflike parts beneath each flower head have fringed edges.
Flowering time: In US gardens it blooms in summer.
Fruit: Small straw-colored or pale blue seeds, about ⅛–3/16 in (4–5 mm) long, with a tuft of short bristles.

Look-alikes

Mountain bluetCentaurea montana

Mountain bluet grows as a perennial clump and has broader lower leaves. Cornflower is an annual with narrow, hairy leaves.

Why they get mixed upBoth can have fringed blue flower heads and may be called bachelor’s button.

Where it lives

Typical habitats: Gardens
Roadsides
Grasslands
Disturbed ground
Range: Native to Europe and western Asia. It has across much of the US, including Washington and Tennessee, and grows in fields, roadsides, and other disturbed places.

Growing it

Care: An easy annual that reseeds and naturalizes readily, so it can turn weedy. It's popular in cottage gardens, meadows, and as a cut flower.
Propagation: Spreads only by seed.

Name and classification

Varieties and forms: Garden plants may have blue, white, pink, or purple flowers, including double-flowered forms.

Conservation

IUCN Red List: NENot EvaluatedNot yet assessed

Culture and stories

Culture and stories: Corning used a blue cornflower pattern on its glassware for decades.

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