Selected images for spotted knapweed (Centaurea stoebe ssp. micranthos)
Spotted knapweed is an herbaceous biennial or perennial plant that invades open areas throughout most of the United States. Its name is derived from the black margins of the flower bract tips which give the flower heads a spotted look. A basal rosette of deeply lobed leaves is produced the first year. Rosette leaves are deeply lobed, petiolate and approximately 8 in. (20 cm) long. Flowering stems are 2/3- 4 ft. (0.2-1.2 m) tall and branched. Stem leaves are alternate and may be slightly lobed or linear. Leaves become smaller and less lobed toward the apex. Flowering occurs in the early summer. Flowers are purple to pink in color and occur on small flower heads. Spotted knapweed invades a wide variety of habitats including pastures, open forests, prairies, meadows, old fields, and disturbed areas. It displaces native vegetation and reduces the forage potential for wildlife and livestock. Spotted knapweed is native to Europe and western Asia. It was accidentally introduced into North America in contaminated alfalfa and clover seed in the late 1800s.
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1459272 spotted knapweed Centaurea stoebe ssp. micranthos Plant(s) Steve Dewey |
5374335 spotted knapweed Centaurea stoebe ssp. micranthos Flower(s) Joseph M. DiTomaso |
0021034 spotted knapweed Centaurea stoebe ssp. micranthos Flower(s) Norman E. Rees |
5392027 spotted knapweed Centaurea stoebe ssp. micranthos Flower(s) John M. Randall |
1459269 spotted knapweed Centaurea stoebe ssp. micranthos Plant(s) Steve Dewey |
1459267 spotted knapweed Centaurea stoebe ssp. micranthos Plant(s) Steve Dewey |
1557011 spotted knapweed Centaurea stoebe ssp. micranthos Foliage John Cardina |
1551078 spotted knapweed Centaurea stoebe ssp. micranthos Fruit(s) Ken Chamberlain |
5391592 spotted knapweed Centaurea stoebe ssp. micranthos Fruit(s) Barry Rice |
2308109 spotted knapweed Centaurea stoebe ssp. micranthos Infestation John M. Randall |
5374334 spotted knapweed Centaurea stoebe ssp. micranthos Plant(s) Joseph M. DiTomaso |
