Knapweed Studies

Centaurea calcitrapa  RED STAR-THISTLE
Centaurea cyanus  CORNFLOWER
Centaurea diluta  LESSER STAR-THISTLE
Centaurea nigra HARDHEADS (=LESSER KNAPWEED)
Centaurea scabiosa GREATER KNAPWEED

Centaurea debeauxii  CHALK KNAPWEED



 
 
Greater Knapweed 
Centaurea scabiosa
Lesser Knapweed (=Hardheads)
Centaurea nigra
Chalk Knapweed 
Centaurea debeauxii
Purple flowerhead (sometimes pale and occasionally white). 
Rayed and larger (hence the name Greater)
NB: when the flowers first appear the rays might not be there and later they often fall off. 
Purple flowerhead, and much smaller than the Greater (hence the name Lesser).
NB: occasionally rayed forms occur.
Bracts (involucre?) underneath the flower, larger and globose in shape.  Bracts (involucre?) underneath the flower, smaller and longer than wide in shape. 
Leaves more substantial and the lower leaves are distinctive and different Smaller leaves more regularly spaced up the stem right up to the bracts
Tall plant up to a metre and a half in height; a greater size. Tall plant up to a metre in height but diminutive forms occur, ground hugging with a stem completely hidden

Lesser Knapweed (=Hardheads)
on the top of Mill Hill
Species under enquiry


 1 November 2017

 

Greater Knapweed on Mill Hill (top)


 



25 October 2017
After the gales, a brief period of weak sunshine cast long shadows in the late afternoon, and I was pleasantly surprised to see an active Clouded Yellow Butterfly immediately on the upper meadow (north of the top car park) of MiIl Hill.  Nectar plants were few and it was restless until it spent a second on the purple flower of one of the few remaining Greater Knapweed.

6 October 2017

Dead plants of mostly Lesser Knapweed
Verges of the Down's Link Cyclepath,  south of the Cement Works

24 August 2017

The prostrate form of Hardheads are overall smaller than the usual upright plants. On less fertile shallower drier soil, this plant adopts a prostrate habit. It is still has a long stem and usually has a single flowerhead. The stem pushes its way through dense vegetation but lies upon or just above the ground, rather than being held erect
 

20 August 2017

Chalk Knapweed
Centaurea debeauxii
if this new species is accepted
Downs Link Cyclepath, Upper Beeding, Sussex. Very chalky. It could have an alluvium overlay. Inauthentic wildlife meadow, may have been seeded.


18 August 2017

Rayed form of Centaurea nigra
Stonechat Junction, Bridlepath junction between Mossy Bottom and Southwick Hill
Donws north of East Shoreham


17 August 2017

Lesser Knapweed (=Hardheads) on the top of Mill Hill
Centaurea nigra

2009 - 2017

Lesser Knapweed (=Hardheads)
Centaurea nigra
Far bottom left: identified as Centaurea debeauxii

Chalk Knapweed
Centaurea debeauxii

Downs Link Cyclepath, Upper Beeding, Sussex. Very chalky. It could have an alluvium overlay. Inauthentic wildlife meadow, may have been seeded.

Greater Knapweed Study
Centaurea scabiosa

23 July 2017

  RED STAR-THISTLE
Centaurea calcitrapa
Anchor Bottom


17 July 2017

Greater Knapweed Study
Centaurea scabiosa
Mill Hill

7 August 2017

21 July 2016

8 September 2015

24 June 2015

Knapweed Broomrape
Orobanche elatior
Mill Hill

2013

Marbled White








August 2010
 

Hornet Robber Fly
Common Blue Butterfly
Brown Argus
Wall Brown

Greater Knapweed Study
Centaurea scabiosa

23 July 2009
 

Greater Knapweed Meadow (upper part of Mill Hill)
Painted Lady
Peacock Butterfly

16 July 2009
Greater Knapweed Butterfly Study


Painted Lady
Six-spotted Burnet Moth
Peacock Butterfly

 
Small Skipper on Greater Knapweed
2 July 2009
Marbled White on Greater Knapweed
19 June 2009
Small Skipper on Greater Knapweed
 

 
Hardhead
27 May 2009
Painted Lady
 August 2010
Common Blue Butterfly
 
 



 
 

Lesser Knapweed (=Hardheads)
Centaurea nigra

Left: Diminutive specimen with hardly any stem