BugwoodWiki Article

brown knapweed
Centaurea jacea L.

Overview

Appearance
Centaurea jacea is a perennial plant that grows 1-4 ft. (0.3-1.2 m) tall. The stems are ridged and may have purple stripes.
Foliage
The basal leaves are oblanceolate to elliptic and 2-10 in. (5 -25 cm) long. Leaves become smaller as they ascend the stem. These smaller leaves are lanceolate and attach directly to the stem.
Flowers
The brown bracts of the inflorescence give this plant its common name. Flowering occurs from June to October, when rose to purple flowers appear in 1-1.25 in. (2.5-3.2 cm) wide, solitary heads at the tips of the branches.
Fruit
Centaurea jacea produces small light brown, plumeless seeds; about 12 per head.
Ecological Threat
Centaurea jacea is an aggressive invader preferring moister, cooler conditions than other knapweed species. It can tolerate partial shade. It can invade grasslands, open woods, meadows, pastures, woodland clearings, and cutover areas of forest crowding out native plants or forage. Centaurea jacea is native to Europe.

Resources

Selected Images


1350056
1350056

brown knapweed
Centaurea jacea
Plant(s)
Cindy Roche
5436660
5436660

brown knapweed
Centaurea jacea
Plant(s)
Bruce Ackley
5436657
5436657

brown knapweed
Centaurea jacea
Foliage
Bruce Ackley
5436650
5436650

brown knapweed
Centaurea jacea
Foliage
Bruce Ackley
5474974
5474974

knapweeds
Centaurea spp.
Foliage
Rob Routledge
1350057
1350057

brown knapweed
Centaurea jacea
Flower(s)
Cindy Roche
5436654
5436654

brown knapweed
Centaurea jacea
Flower(s)
Bruce Ackley
5436658
5436658

brown knapweed
Centaurea jacea
Flower(s)
Bruce Ackley
5474971
5474971

knapweeds
Centaurea spp.
Flower(s)
Rob Routledge
5474972
5474972

knapweeds
Centaurea spp.
Flower(s)
Rob Routledge
5436663
5436663

brown knapweed
Centaurea jacea
Flower(s)
Bruce Ackley
5436664
5436664

brown knapweed
Centaurea jacea
Seed(s)
Bruce Ackley

Maps


EDDMapS Distribution - This map is incomplete and is based only on current site and county level reports made by experts, herbaria, and literature. For more information, visit www.eddmaps.org

EDDMapS Distribution

State Regulated List - This map identifies those states that list this species on their regulated list. For more information, visit Invasive.org

State Regulated List

Taxonomic Rank

Kingdom: Plantae
Phylum: Magnoliophyta
Class: Magnoliopsida
Subclass: Asteridae
Order: Asterales
Family: Asteraceae
Genus: Centaurea

Other System Links

Plants: CEJA
Bayer: CENJA
GRIN: 9821
ITIS: 36962
NPDN Pest: PBFARBE

Synonyms and Other Names

Other Common Names:
brown knapweed

Categories

Category: Forbs/Herbs