Common or Black Knapweed Centaura nigra
![](https://lizzieharper.co.uk/wp-content/uploads/2022/06/Common-or-Black-Knapweed-Centaura-nigra-295x525.jpg)
Common or Black Knapweed Centaura nigra, showing diverse leaf shape and typical spherical, purple flowering heads.
Common or Black Knapweed Centaura nigra, showing diverse leaf shape and typical spherical, purple flowering heads.