West Mill Lane, Small Dole, Henfield, W Sussex. Wide dark bits of phyllaries hiding the pale bases - Chalk Knapweed instead has lanceolate bits so that the pale bases of the bracts are visible.

Common / Black Knapweed (Centaurea nigra) (03/07/2021) West Mill Lane, Small Dole, Henfield, W Sussex. Wide dark bits of phyllaries hiding the pale bases - Chalk Knapweed instead has lanceolate bits so that the pale bases of the bracts are visible.

Edburton Road (verge), Henfield, W Sussex. Black parts of phyllaries in Chalk Knapweed instead are lanceolate so that you can see the green parts.

Common / Black Knapweed (Centaurea nigra) (03/07/2022) Edburton Road (verge), Henfield, W Sussex. Black parts of phyllaries in Chalk Knapweed instead are lanceolate so that you can see the green parts.

Southbank Equestrian, Henfield (arena bank). This is why Common not Slender/Chalk Knapweed - these large and closely packed phyllaries.

Common / Black Knapweed (Centaurea nigra) (29/06/2025) Southbank Equestrian, Henfield (arena bank). This is why Common not Slender/Chalk Knapweed - these large and closely packed phyllaries.

West Mill Lane, Small Dole, Henfield, W Sussex. Chalk Knapweed instead doesn't have such a thickened peduncle (bit beneath flowerhead (capitula). Also these leaves are broader and greyer than Chalk Knapweed.

Common / Black Knapweed (Centaurea nigra) (19/07/2021) West Mill Lane, Small Dole, Henfield, W Sussex. Chalk Knapweed instead doesn't have such a thickened peduncle (bit beneath flowerhead (capitula). Also these leaves are broader and greyer than Chalk Knapweed.

West Mill Lane, Small Dole, Henfield, W Sussex. Again note the greyish-green nature of the plant and the wider leaves (than Chalk Knapweed).

Common / Black Knapweed (Centaurea nigra) (03/07/2021) West Mill Lane, Small Dole, Henfield, W Sussex. Again note the greyish-green nature of the plant and the wider leaves (than Chalk Knapweed).

Common / Black Knapweed (Centaurea nigra) (03/07/2021) West Mill Lane, Small Dole, Henfield, W Sussex. The flowers are larger than Chalk Knapweed.

Common / Black Knapweed (Centaurea nigra) (19/07/2021) West Mill Lane, Small Dole, Henfield, W Sussex. A young bud.

Common / Black Knapweed (Centaurea nigra) (17/07/2022) Footpath rear of water treatment plant, Small Dole, Henfield, W Sussex.

Common / Black Knapweed (Centaurea nigra) (03/07/2022) Edburton Road (verge), Henfield, W Sussex.

West Mill Lane, Small Dole, Henfield, W Sussex. Leaves broader than the narrow ones of Chalk Knapweed.

Common / Black Knapweed (Centaurea nigra) (19/07/2021) West Mill Lane, Small Dole, Henfield, W Sussex. Leaves broader than the narrow ones of Chalk Knapweed.

Common / Black Knapweed (Centaurea nigra) (29/06/2025) Southbank Equestrian, Henfield (arena bank).

Footpath rear of water treatment plant, Small Dole, Henfield, W Sussex. Classic swollen stem beneath the flowerhead (Chalk Knapweed not so swollen).

Common / Black Knapweed (Centaurea nigra) (17/07/2022) Footpath rear of water treatment plant, Small Dole, Henfield, W Sussex. Classic swollen stem beneath the flowerhead (Chalk Knapweed not so swollen).

Footpath rear of water treatment plant, Small Dole, Henfield, W Sussex. And stem more grooved than Chalk Knapweed.

Common / Black Knapweed (Centaurea nigra) (17/07/2022) Footpath rear of water treatment plant, Small Dole, Henfield, W Sussex. And stem more grooved than Chalk Knapweed.

West Mill Lane, Small Dole, Henfield, W Sussex. An upper stem leaf much broader than those of Chalk Knapweed. Note the hairyness makes this plant greyer-green than Chalk Knapweed.

Common / Black Knapweed (Centaurea nigra) (19/07/2021) West Mill Lane, Small Dole, Henfield, W Sussex. An upper stem leaf much broader than those of Chalk Knapweed. Note the hairyness makes this plant greyer-green than Chalk Knapweed.

Common / Black Knapweed (Centaurea nigra) (19/07/2021) West Mill Lane, Small Dole, Henfield, W Sussex.

Common / Black Knapweed (Centaurea nigra) (29/06/2025) Southbank Equestrian, Henfield (arena bank).

Common / Black Knapweed (Centaurea nigra) (17/07/2022) Footpath rear of water treatment plant, Small Dole, Henfield, W Sussex.

Woods Mill Nature Reserve, Small Dole, Henfield, W Sussex (in the small field leading to the field with the owl box in it). Sometimes Common Knapweed can exist in a rayed form, as here. It's definitely Common and not Greater Knapweed (the flowers look very similar) because the latter has very different leaves and bracts.

Common / Black Knapweed (Centaurea nigra var. radiata) (17/07/2022) Woods Mill Nature Reserve, Small Dole, Henfield, W Sussex (in the small field leading to the field with the owl box in it). Sometimes Common Knapweed can exist in a rayed form, as here. It's definitely Common and not Greater Knapweed (the flowers look very similar) because the latter has very different leaves and bracts.

Woods Mill Nature Reserve, Small Dole, Henfield, W Sussex (in the small field leading to the field with the owl box in it).

Common / Black Knapweed (Centaurea nigra var. radiata) (17/07/2022) Woods Mill Nature Reserve, Small Dole, Henfield, W Sussex (in the small field leading to the field with the owl box in it).