Ricin is a powerful protein toxin found in the castor plant, Ricinus communis. Ricin is present in all parts of the plant but is particularly concentrated in the seeds. The toxin could be used as a biological weapon. Purified toxin can be found in a crystalline form, as a dry lyophilized powder, or dissolved in liquid. Ricin acts by inhibiting protein synthesis.
Iowa State University
Iowa State University Center for Food Security and Public Health, "Ricin" (2004). Center for Food Security and Public Health Technical Factsheets. 111.