Common names: castor bean
Ricinus communis (castorbean) is an herbaceous plant or semi-woody large shrub or small tree (family Euphorbiaceae). It grows quickly in mild climates and has escaped cultivation to become a noxious weed in southern and central California. Castorbean contains ricin, an extremely toxic chemical that can kill an adult who consumes only four to eight seeds. Handling foliage and seeds can cause severe dermatitis.Cal-IPC Rating: Limited
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.
Weed RIC Management Notes
- Management Notes - Information on management techniques and effectiveness from the University of California Cooperative Extension’s Weed Research & Information Center.
Cal-IPC Newsletter Articles
- Don’t sell a pest: A new partnership to prevent plant invasions through horticulture. Connick, Sarah; Gerel, Mike. Vol 13, Issue 2
- The basal bark method of applying triclopyr herbicide. Neill, Bill; Angeles, Team Arundo. Vol 13, Issue 1
- Which weeds dominate southern California urban riparian systems?. Burkhart, Brad; Kelly, Mike. Vol 13, Issue 1
- Roundup of Arundo projects reveals commitment, strategic weakness. Kelly, Mike. Vol 07, Issue 2
- Results of the CalEPPC questionnaire at Symposium ’98 in Ontario. DiTomaso, Joe. Vol 06, Issue 4
- Legendary stewardship award. Goode, Suzanne. Vol 06, Issue 2
- Killing the beast: A cooperative approach for control of Arundo donax in the Santa Ana River watershed. Stein, Eric D.; Vartanian, Valerie. Vol 05, Issue 3
- Control of exotic plants in an herbaceous understory. Perala, Christine; Hoover, Doris A.; Parra-Szijj, E.A.. Vol 01, Issue 3
Cal-IPC Symposium Presentations
Presentations are linked where available. Where a presentation is not available, find more information by reading the abstract in the Cal-IPC Symposia Archive.
- Mapping weeds and rare plants to inform management and conservation in the Zaca and Jesusita fires. Calloway, Stephanie; Schneider, Heather; Knapp, Denise (2018)
- The Matilija Dam Ecosystem Restoration Project. Reinoehl, Steven; Zaich, Craig (2010)
- How to develop user-friendly riparian corridor invasive exotic species/habitat restoration master plans: Experiences on the San Diego and Otay Rivers. Burkhart, Brad; Kelly, Mike (2007)
- Partnering to prevent invasions of plants of horticultural origin. Connick, Sarah; Gerel, Mike (2004)
- Exotic plants in the Sonoran desert region, Arizona and Sonora. Devender, Thomas R. Van; Frlger, Richard S.; M., Alberto Burquez (1997)
Other Ricinus communis Information
- CalPhotos - Images of plants taken mostly in California.
- Calflora - See the distribution of this species on Calflora's map of California.
- CalWeedMapper - Distribution information with ability to determine regional priorities.
- Jepson Online Interchange for California Flora - Information on taxonomy, biology, and distribution from UC Berkeley's Jepson Herbarium.
- USDA PLANTS Database - Federal database with information on identification and distribution, and links to websites in individual states.