Pal Hermansen / Common brimstone (Gonepteryx rhamni) flying in summer meadow amongst Knapweed (Centaurea sp). Hvaler, Ostfold, Norway. July.

Ann & Steve Toon / Wildflowers, including poppies (Papaver rhoeas), corn marigold (Glebionis segetum), cornflowers (Centaurea cyanus) and corn chamomile (Anthemis arvensis), being grown for seed by Landlife, Fir Tree Fa...

Paul Harcourt Davies / Floral colour in fields on the Piano Grande from Poppies (Papaver rhoeas), Cornflowers (Centaurea), Mustard (Brassica) and Mayweed (Anthemis), Umbria, Italy, June

Paul Harcourt Davies / Cornflowers (Centaurea cyanus) and poppies (Papaver rhoeas) growing on fallow fields near Orvieto, Umbria, Italy. June 2010

Wild Wonders of Europe / Wothe / Red poppy (Papaver rhoeas) Brown knapweed (Centaurea jacea) and Forking larkspur (Delphinium / Consolida regalis) flowers, Western Carpathians, Slovakia, Europe, May 2009

Nick Garbutt / Common knapweed (Centaurea nigra), close up. North Tyrol, Austria, June.

Nick Garbutt / Common knapweed (Centaurea nigra) in ancient alpine meadow with hut. in distance, North Tyrol, Austria. June 2018.

Nick Upton / Colony of Large knapweed aphids (Uroleucon jaceae) feeding on Black / Common knapweed (Centaurea nigra) stem, Mellis Common, Suffolk, UK May.

Martin Grimm/ BIA / Common Sunflower (Helianthus annuus) and Cornflower (Centaurea cyanus) field, Hesse, Germany

Martin Grimm/ BIA / Common Sunflower (Helianthus annuus) and Cornflower (Centaurea cyanus) field, Hesse, Germany

Phil Savoie / Six spot burnet moth (Zygaena filipendulae) on Black knapweed (Centaurea nigra) Pentwyn farm SSSI, Gwent Wildlife Trust, Monmouthshire Wales UK, July.

Andy Sands / Chalkhill blue butterfly (Polyommatus coridon) male feeding on flower of Knapweed (Centaurea nigra), Hertfordshire, England, UK August