Senecio jacobaea (tansy ragwort)

Senecio jacobaea

Photo courtesy Joseph DiTomaso

Senecio jacobaea (tansy ragwort) is a noxious biennial, perennial, or winter annual forb/herb (family Asteraceae) found in northern California, along disturbed places, roadsides, and waste sites. This plant is poisonous if consumed by forage animals. Bees foraging on tansy ragwort produce bitter honey that is tainted with alkaloids.

Cal-IPC Inventory rating: Limited

Cal-IPC Resources on Senecio jacobaea

• California Invasive Plant Inventory Plant Assessment Form - Information gathered by Cal-IPC on the impacts, rate of spread, and distribution of invasive plants in California. Does not include management information.
• CalWeedMapper - Statewide maps, climate models, and reports.
• Species account from Invasive Plants of California's Wildlands - Includes biology and management information.
• Cal-IPC News - Articles from our quarterly newsletter. Each issue is available as a pdf. List of articles on Senecio jacobaea.
• Cal-IPC Symposium Proceedings - Presentations and papers from our annual Symposium.List of articles on Senecio jacobaea.

Cal-IPC News Articles

• (1995). Biological control of invasive exotic pest plant species: A report on the importance of maintaining and enhancing our nation's biological control capabilities. CalEPPC News. 3: 6-10.
• Elliott, W. (1994). German ivy engulfing riparian forests and heading for the uplands. CalEPPC News. 2: 9.
• Pitcairn, M. (2000). All weeds that have approved biological control agents, accidental introductions and others. CalEPPC News. 8.

Cal-IPC Symposium Proceedings

• Carrithers, V. F. (1997). Using Transline* herbicide to control invasive plants. California Exotic Pest Plant Council Symposium '97. Concord, CA.
• Thomsen, C. D., W. A. Williams, et al. (1996). Yellow starthistle management with grazing, mowing, and competitive plantings. California Exotic Pest Plant Council Symposium '96. San Diego, CA.

Other Resources on Senecio jacobaea

• USDA PLANTS database - Federal database with information on identification and distribution, and links to websites in individual states.
• Jepson Online Interchange for California Flora - Information on taxonomy, biology, and distribution from the UC Berkeley Jepson Herbarium.
• CalFlora - Distribution information by county based on submitted observations and herbarium specimens.
• The Nature Conservancy Management Summary - Information compiled by TNC land managers. Photos included for some species.
• Encycloweedia - Plants rated as noxious weeds by the California Department of Food and Agriculture.
• CalPhotos - Images of plants taken mostly in California.

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