In a recent visit to London’s Regent Park, I noticed a beautiful and exotic looking plant. Ricinus communis commonly known as the Castor Oil Plant is a species in the spurge family or the Euphorbiaceae family of plants. It is part of the monotypic genus.
It is a fast-growing shrub. In its native habitat, it can grow up to 12m or 39ft tall. However, in climates like England, it is grown as an annual. Therefore it only grows to 1m or 3ft.
The glossy palmate leaves of Ricinus communis usually have a darker deep reddish-purple color. Later they turn green. Ricinus communis is native to the Mediterranean, East Africa, and India. But it is grown in many places and grows well in the tropics as well.
Ricinus communis is grown both for its beauty as well as its medicinal purpose. Ricinus communis seeds that are all called beans or castor beans. They are not actually beans. They are used to make castor oil. The seeds are produced in red spiky capsules that are rather dramatic in a garden. The flowers are smaller and not as significant as the seed pods. The seed pods stand out more. The seeds are poisonous yet they produce castor oil. The leaves are used for other medicinal purposes that help the liver. Castor oil is also used as motor oil.
Castor Oil plants like the full sun so south-facing or west-facing exposure is best. Plant them in well-drained rich soil. The flowers are yellow but not as significant as the color of the leaves and stems and the seed pods.
Ricinus communis has a variety of cultivated versions:
- Carmencita Red: has reddish stems and darker purplish leaves but red seed pods grow to 1.5 meters as an annual
- Carmencita Pink: is a green variety and has pink seed pods, grows to 1.5 meters as an annual
- gibsonii: which has reddish leaves and veins and bright pink/red seed pods, grows to 1.5 meters as an annual
- Impala: is smaller and has reddish foliage and stems, grows to 1 meter as an annual
- Red Spire: in contrast is a tall variety that grows to 3 meters still with reddish stems and red-bronze leaves
- New Zealand Purple: has deep purple-colored leaves and seed pods but they turn more red as they ripen, grows to 1.5 meters as an annual
- Zanzibarensis: is another tall variety that grows to 3 meters and has green leaves with white midribs
Castor beans are considered poisonous but alos provide a lot of benefits. The poison can be extracted. But if the beans are ingested there will be delayed symptoms as late as a day and a half after ingestion. The seeds are toxic only if they are chewed or broken. Swallowing the whole beans or seeds might pass through the human system without harm.