BugwoodWiki Article

black knapweed
Centaurea nigra L.

Overview

Appearance
Centaurea nigra is a perennial plant that can grow from 1-3 ft. (0.3-0.9 m) tall.
Foliage
Leaves, near the base, are petiolate, oblanceolate, shallowly dentate and 2-10 in. (5-25 cm) long. As leaves move up the stem, they become smaller, sessile, linear, and entire.
Flowers
Flowering occurs from June to October, when purple (rarely white) flowers appear in heads at the tips of the branches.
Fruit
Fruit is a tan, hairy achene 0.08-0.12 in. (2-3 mm) long, may have a small, dark pappus.
Ecological Threat
Centaurea nigra is native to Europe and was first found in the United States in 1895 in Pullman, Washington. Preferred habitat includes roadsides, waste places, fields and clearings.

Selected Images


1350054
1350054

black knapweed
Centaurea nigra
Plant(s)
Cindy Roche
5437858
5437858

black knapweed
Centaurea nigra
Plant(s)
Bruce Ackley
5437857
5437857

black knapweed
Centaurea nigra
Plant(s)
Bruce Ackley
5374350
5374350

black knapweed
Centaurea nigra
Seedling(s)
Joseph M. DiTomaso
1350055
1350055

black knapweed
Centaurea nigra
Flower(s)
Cindy Roche
5374349
5374349

black knapweed
Centaurea nigra
Flower(s)
Joseph M. DiTomaso
5437855
5437855

black knapweed
Centaurea nigra
Seed(s)
Bruce Ackley
5437856
5437856

black knapweed
Centaurea nigra
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: CENI2
Bayer: CENNI
GRIN: 104128
ITIS: 36968
NPDN Pest: PBFARBH

Synonyms and Other Names

Other Common Names:
black knapweed

Related Scientific Names:

Centaurea jacea ssp. nigra (L.) Bonnier & Layens(Synonym)

Categories

Category: Forbs/Herbs