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How to Manage Pests

Identification: Weed Photo Gallery

Annual sowthistle

Scientific name: Sonchus oleraceus (Family Asteraceae)

Life stages of Annual sowthistle top picture bottom left picture bottom right picture

Click on image to enlarge

DESCRIPTION:
Annual sowthistle is a widespread annual weed. It is commonly found in California's Central Valley and coastal areas where it grows year-round. Its seeds germinate only in the top 1/2 inch (1.2 cm) of soil, so preplant cultivations and deep plowing are effective controls. Seed leaves are stalked and covered with a powdery, gray bloom. They have smooth-edges and are spoon-shaped. True leaves have wavy edges and prickles. Upper leaf bases clasp the stems with clawlike lobes. Mature plant may reach a height of 3 to 6 feet (0.9 - 1.8 m). Yellow flowers mature into white, fluffy seed heads, similar to common groundsel. Hollow stems secrete milky juice when cut or crushed.

Broadleaf ID illustration.


Statewide IPM Program, Agriculture and Natural Resources, University of California
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For noncommercial purposes only, any Web site may link directly to this page. FOR ALL OTHER USES or more information, read Legal Notices. Unfortunately, we cannot provide individual solutions to specific pest problems. See How to manage pests, or in the U.S., contact your local Cooperative Extension office for assistance. /PMG/WEEDS/annual_sowthistle.html revised: March 11, 2008. Contact webmaster.