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Species
Information
- Italian
(plumeless) thistle
- Carduus
pycnocephalus
L.
- USDA
Symbol: CAPY2
- Oregon
Noxious Weed Designation: B
- Pictures
Identification:
Annual or sometimes biennial; blooms May to June. Grows 1 to 4 ft tall. Stems have spiny wings. Leaves deeply cut into 2 to 5 pairs of lobes, have white spots and undersurface slightly woolly. Flowers purplish to pinkish, borne in cylindrical heads either solitary or in clusters of more than 5. Bracts hairy. Fruits from outer part of flower head are gray in color and inner portion are yellowish to tan.
Impacts:
Italian thistle is native to southern Europe. It infests roadsides and waste areas, and has become a major problem on hill pasture land in Douglas County, Oregon. Once established, it spreads rapidly and forms dense stands which displace more desirable vegetation and exclude livestock.
Biological
Controls: Two approved biocontrol agents, a seed head weevil and a stem-boring fly, have been successfully established in Oregon.
Oregon
Maps of Italian Thistle Distribution
Links:
USDA
Plants Database information on
Italian
thistle
GRIN
Database information on Italian
thistle
Oregon Department
of Agriculture information on Italian
thistle
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