black knapweed
Centaurea nigra L.


Centaurea nigra is a perennial plant that can grow from 1-3 ft. (0.3-0.9 m) tall.
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.
Flowering occurs from June to October, when purple (rarely white) flowers appear in heads at the tips of the branches.
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.

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EDDMapS Distribution

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State Regulated List

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

Taxonomic Rank

Kingdom: Plantae
Phylum: Magnoliophyta
Class: Magnoliopsida
Subclass: Asteridae
Order: Asterales
Family: Asteraceae
Genus: Centaurea
Subject: Centaurea nigra L.

Synonyms and Other Names

Other Common Names:
black knapweed

Related Scientific Names:
Centaurea jacea ssp. nigra (L.) Bonnier & Layens (Synonym)


Plants - Forbs/Herbs