are castor bean plants poisonous
Toxic Terror, Care. A poisonous plant in all its parts, castor bean's namesake beans (i.e., the seeds) are especially toxic. In fact, they are the source of the infamous poison, ricin.astor beans are not true beans; that's just a nickname. The plants belong to the Euphorbiaceae family. That makes them relatives of poinsettia plants and wood spurge. Tropical plants such as castor beans have a certain cachet in the Northern landscape, where they offer an exotic look.