Get it on Google Play

 Filters: 

 

Common Knapweed Centaurea nigra 

 
 
Wildlife GardenWildlife garden plant
Attracts BeesBees are attracted to this plant
Attracts ButterfliesButterflies are attracted to this plant
Attracts HoverfliesHoverflies are attracted to this plant
Perennial Life CyclePerennial life cycle
Daisy-Like FlowersDaisy-like flowers
Purple FlowersPurple flowers
Many PetalsMany petals
Jun-Sep Flowering
period
Elongated LeavesElongated leaves
Hairy-Edged LeavesHairy-edged leaves
Ribbed StemRibbed stem
Tap RootTap root
70cmMaximum height
 
 
  Main image of Common Knapweed

© 2020-2025 Adrian Briggs

 

Common Knapweed is a native perennial plant of the UK, typically found growing in grassland, meadow and waste ground, to a mature height of up to 70cm.

Knapweed is named after the Middle English 'knopweed', meaning a plant with a 'knop', referring to the plant's hard brown flower buds. Common Knapweed can be distinguished from Greater Knapweed by its: shorter height; simple elongated leaves (rather than lobed leaves); non-spherical flower bud; and a composite flowerhead made up only of disc florets of similar-length petals (although outer ones will sometimes have petals with a rayed appearance).

Botanic classification and naming: Common Knapweed is a member of the Daisy (Asteraceae) family. The genus name 'Centaurea' identifies the plant as a Knapweed and its species name 'nigra' means 'black'.

Benefits: Pollinated by bees, butterflies and hoverflies. The plant produces a large volume of nectar and attracts a wide range of butterflies, including the Brimstone and Common Blue. Caterpillars of the Black-Veined and Scarce Forester moths feed on this plant.

Benefits to wildlife are also indicated with orange icons in the plant profile bar at the top.

 

 
Flower of Common Knapweed

© 2021 Adrian Briggs

 

Flowers:
Common Knapweed usually flowers between June and September.

Flower colour:

Flower Colour Purple

Purple

Flower shape:

Flower Shape  Daisy-like

Daisy-like

Petals:

Petal Number =  Many

Many

Leaf of Common Knapweed

© 2021 Adrian Briggs

 

Leaves:

Leaf Shape:

Leaf Shape is Elongated

Elongated

Leaf Margins:

Leaf Margin is hairy

hairy

Stem of Common Knapweed

© 2021 Adrian Briggs

 

Stem and Roots:

Stem shape:

Stem Shape is Ribbed

Ribbed

Root type:

Root Type is Tap

Tap