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Meadow Knapweed Asteraceae
(=Compositae), the aster family
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Background
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 Meadow
knapweed is native of Europe and can grow in many environmental conditions.
Meadow knapweed is believed to be a fertile hybrid resulting from
crossbreeding black knapweed (C. nigra) and brown
knapweed (C. jacea). |
Description
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 Meadow
knapweed is a perennial plant up to 3 1/2 feet
tall. Basal leaves are up to 4 inches long, slender, have a
petiole, and may
be entire, toothed, or
lobed. Stem leaves usually don't have a petiole and
are much smaller. Stems are many branched and tipped by a solitary flower
head up to 1 inch wide. Flowers are pink to reddish purple and are produced
from midsummer the rough fall. Flower head bracts are 1/4 inch wide, and the
tips range from a comblike fringe to a blunt ruffled edge. Bract tips range
from tan to dark brown or, rarely, black. Seeds are brown to gray in color
and are tipped by plumes that fall off at maturity. |
Distribution
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 Meadow
knapweed is found from British Columbia to northern California. |
Control
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A biological control agent has provided fair results on meadow knapweed in
Washington but is still under evaluation in Idaho. Herbicides are available
for control. |
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© 1999 University of Idaho:
Text and photographs for these pages from Idaho's Noxious Weeds, by
Robert H. Callihan and Timothy W. Miller (revised by Don W. Morishita
and Larry W. Lass).
Please contact: Ag Publishing, University of Idaho, Moscow,
Idaho 83844-2240; 208 882-7982 visit the Resources for Idaho website at
http://info.ag.uidaho.edu, for more information about this or other
publications.
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