(Carduus pycnocephalus L.)
Weed ID Links
Photo from: Yolo County Resource Conservation District,
Roots: The Italian thistle has long, thick taproots, it is
occasionally branched, and it is capable of penetrating 40 cm or more deep
into the soil. (1)
Stems/Leaves: Its stems and leaves are quite prickly.
(1), (4), (5)
Flowers: It has deeply lobed disc flowers. They are
purple to pink and are rarely white. The seed heads are spine tipped, and are overlapping
in several rows. The flowers are
flat, and densely covered with cream colored bristles interspersed among
the disk flowers. Insects pollinate it more
than any other pollinator. (1, 3)
Fruits and Seeds: The seeds are curved and slightly compressed.
It is sometimes slightly 4 to 5 sided in cross section. (3)
Method of Reproduction: When Flower buds seeds pop out and are
taken by wind or are carried on animals until seed falls off. (1)
Favorable to Infestation: Warm with some moisture
environments is best for this plant. (1), (2)
Non chemical: You are able to mow to help reduce this plant
but it will not eliminate the plant. The Italian thistle recovers
quickly from the buds near the base. After the initial flowering the
best times to mow are 2 to 4 days. Tillage is also a good way for
Background: This plant is native to the Mediterranean
region of Southern Europe. (1)
Distribution: It is distributed throughout the following
areas: Southern North Coast Ranges of California, Sierra Nevada foothills,
Central Coast, San Francisco Bay region, and also South Coast Ranges up
to a height of 3300 ft. (1)
Here are some
1) Steve, Schoenig, EncycloWeedia. [online] available. http://pi.cdfa.ca.gov/weedinfo/carduus.htm#anchor118770.
2) Carla Bossard, Richard Lichti, California Invasive Plant Council. [online] available. http://ucce.ucdavis.edu/datastore/detailreport.cfm?usernumber=24&surveynumber=182.
Dana, Coggon, Noxious Weed Control Board. [online] available.
4) Athena Demetry, Sequoia and Kings Canyon National Parks. [online]
5) Terry Cacek, National Park Service IPM. [online] available.
Madsen date: 4/8/2004.
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