Centaurea nigra

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Centaurea nigra
Centaurea nigra-3233.jpg
Scientific classification e
Kingdom: Plantae
Clade: Angiosperms
Clade: Eudicots
Clade: Asterids
Order: Asterales
Family: Asteraceae
Genus: Centaurea
Species: C. nigra
Binomial name
Centaurea nigra
L.
Centaurea nigra - MHNT
Illustration
small heath butterfly on knapweed

Centaurea nigra is a species of flowering plant in the daisy family known by the common names lesser knapweed, common knapweed and black knapweed. A local vernacular name is hardheads.

It is native to Europe but it is known on other continents as an introduced species and often a noxious weed.

Description[edit]

It is a perennial herb growing up to about a metre in height.

The leaves are up to 25 centimetres (9.8 in) long, usually deeply lobed, and hairy. The lower leaves are stalked, whilst the upper ones are stalkless.

The inflorescence contains a few flower heads, each a hemisphere of black or brown bristly phyllaries. The head bears many small bright purple flowers. The fruit is a tan, hairy achene 2 or 3 millimetres long, sometimes with a tiny, dark pappus. It flowers from July until September.[1] The flowers sometimes are yellow or white

Wildlife value[edit]

In Europe, the plant is an important source of food for the European goldfinch, honey bee, lime-speck pug moth, and the following butterflies: large skipper, meadow brown, small heath, painted lady, peacock, red admiral, small copper and small skipper.

Similar species[edit]

Brown knapweed (Centaurea jacea) is different in having pale brown bract appendages, no pappus. Flowers August until September.

References[edit]

  1. ^ Rose, Francis (1981). The Wild Flower Key. Frederick Warne & Co. pp. 386–387. ISBN 0-7232-2419-6. 

External links[edit]