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Knapweed
Knapweed
Knapweed, common name for several plants in the daisy family. Common knapweed is a perennial with erect, hairy stems up to 1 m (3 ft) high and green or greyish leaves which vary from unlobed to deeply pinnately lobed. The flower heads are knob-shaped and encased with a whorl of black- or brown-fringed bracts. The slender, tubular florets that make up the flower head are all reddish purple. The plant is common on rough ground and in grassy places in Britain and much of Europe. Another common species is brown knapweed, which has a pale brown and irregular fringe to the enveloping bracts and sometimes bears white flowers. Knapweeds belong to the star thistle genus. Many of the species of star thistle found in Europe are weeds of dry soils in the Mediterranean region. They often have spiny enveloping bracts around the flower head and the flowers may be blue, yellow, red, or occasionally white, as well as purple. Another member of the genus is the cornflower which was formerly a common weed of cornfields but is not a knapweed. It has now declined in many areas because of improved agricultural techniques.
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