Pollen of castor bean plant (Ricinus communis). The seeds produce castor oil but they also contain highly toxic lectin called ricin. Ingestion of several seeds may be lethal even to an adult human, first causing burning of the throat and mouth, vomiting, severe abdominal pain, diarrhea, thirst from loss of fluids and electrolytes, and convulsions followed by death. The leaves are less toxic and may cause contact dermatitis. Enhanced SEM. Image width: 91.4 micrometers. Magnification: 1095x if the image is printed 10 cm wide.