Scientific Name: Centaurea jacea

Common Name: brownray knapweed

Other Common Names: brown knapweed, rayed knapweed, brown centaury, horse-knobs, hardheads

Habit: Brown knapweed reproduces by seeds. It, like most other knapweeds, has a taproot system which allows it to suck water and nutrients from nearby plants.

Leaves: The leaves of brown knapweed are egg-shaped or lance shaped. The leaves become smaller as they move up the stem.

Identifying Characteristics: Brown knapweed can be distinguished from other knapweeds due to its brachts, which are tan to brown and paper-like at the edges.

Flower Seed Head: The flower heads of brown knapweed are 1 inch to 1 1/4 inch in diameter. They are ray type flowers and most often are magenta in color. The flowers bloom from June to October.

Seed Fruit: Brown knapweed seeds have tufts on the end and are approximately 1/8 inch long. The seeds are the source of reproduction.

Where Found: Brown knapweed is found throughout the North East and North Western United States. It originated and is found throughout Europe.

  • Life cycle: perennial

  • Milky sap: Not Present

  • Plant type: Herb

  • Thorns: Not Present

  • Plant family: Asteraceae

  • Leaf arrangement: alternate

  • Leaf shape: lance

  • Ochrea: Not Present

  • Leaf margin: lobed

  • Flower color: purple

  • Growth habit: upright and nonwoody

  • Stem: round or oval

  • Leaf structure: simple

  • Leaf hairs: no hairs

  • Flower symmetry: radial symetery

  • Root structure: taproot

  • Leaf stalk: shorter than leaf