Ricinus communis

Ricinus communis_castorbean_JM DiTomaso
Photo courtesy Joseph DiTomaso

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

Cal-IPC Assessment

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.

Cal-IPC Newsletter Articles

Cal-IPC Symposium Presentations

  • Reinoehl, S. and C. Zaich (2010). The Matilija Dam Ecosystem Restoration Project. Cal-IPC 2010 Symposium Ventura, CA, California Invasive Plant Council
  • Burkhart, B. and M. Kelly (2007). How to develop user-friendly riparian corridor invasive exotic species/habitat restoration master plans: Experiences on the San Diego and Otay Rivers. California Invasive Plant Council Symposium 2007. San Diego, CA, California Invasive Plant Council.
  • Connick, S. and M. Gerel (2004). Partnering to prevent invasions of plants of horticultural origin. California Invasive Plant Council Symposium 2004. Ventura, CA.
  • Dickerson, E., C. Brigham, et al. (2004). Ecohelpers: Education and ecological restoration in Southern California. California Invasive Plant Council Symposium 2004. Ventura, CA.
  • Archbald, G. (1998). Mechanical control methods: beyond weed bashing. California Exotic Pest Plant Council Symposium '98. Ontario, CA.
  • Devender, T. R. V., R. S. Frlger, et al. (1997). Exotic plants in the Sonoran desert region, Arizona and Sonora. California Exotic Pest Plant Council Symposium '97. Concord, CA.

Other Ricinus communis Information

  • CalPhotos - Images of plants taken mostly in California.
  • CalFlora - Distribution information based on submitted observations and herbarium specimens.
  • 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.