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



Maps



EDDMapS Distribution

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

State Regulated List

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

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)

Categories


Plants - Forbs/Herbs