Castor bean, castor-oil plant, palma Christi
Ricinus communis
Spurge (Euphorbiaceae) Family

Castor Bean plant

Description: Castor Bean plant leavesThe castor bean is a semi-woody, flowering plant with large, alternate, star-like leaves that grows as a tree in tropical regions and as an annual in temperate regions. Its glossy leaves grow to 15-45 centimeters (6-18 inches long on long stalks with 5-12 deep lobes with coarsely toothed segments.  In some species, the they start off dark, reddish purple gradually changing to a dark green, sometimes with a reddish tinge, as they mature.  Its flowers are very small and inconspicuous but its fruit capsules are often showy. Its fruits grow in clusters at the tops of the plants.  The fruit is spiny, greenish to reddish purple capsules  that contain its seeds.  Its seed is the castor bean which contains ricin, a deadly toxin.  They seeds are large, oval, shiny, and bean-like in appearance.

Castor Bean plant purplish leaves and showy bean stalksLethal dose is around 4-8 seeds and symptoms of poisoning include burning mouth, abdominal pain, nausea, bloody diarrhea, and seizures that can last for up to a week.  Symptoms may be delayed for up to 36 hours but commonly begin in 2-4 hours.

Note: All parts of the plant are very poisonous to eat. The seeds are large and may be mistaken for a beanlike food.

Habitat and Distribution: This plant is found in all tropical regions and has been introduced to temperate regions.

Other uses: The beans can be used as ammo for slingshots.

Castor oil is prepared from castor beans and is used as lubricants, hydraulic fluids, paints, dyes, inks, cold resistant plastics, waxes, nylon, and perfumes.  Heat treatment isolates the ricin toxin and inactivates it.  Still, even harvesting the plant is dangerous with workers commonly suffering long-term nerve damage.


Castor Bean plant leaf

Castor Bean plant young and mature leaves

Castor Bean plants seeds (castor beans)

Castor Bean plant seeds in pod

Castor Bean plant seed in pod

Castor Bean green seeds

Color drawing of Castor Bean plant illustrating the plant's components