The colour of this young Knapweed is dark almost purple. As it opens fully it will become blue and then fade as the flower ages. The colour helps Centaurea montana earn its nickname of Mountain Cornflower or perennial cornflower.
Also see Centaurea Garden Gem or Invasive Weed and Growing Centaurea
New book from Amazon – Diffuse Knapweed Centaurea Asteraceae, Anatolia, Balkans, Biennial plant, Annual plant, Taproot, Head (botany), Leaf, Flower, Seed
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