Native to Africa, Middle East and India castor bean is a tender perennial that is very fast growing and quickly becomes a suckering shrub or small tree. Plants are well branched with watery reddish-purple stems and have palmately lobed leaves that are red, green or variegated, up to 30″ across, and are borne on long petioles attached to the center of the leaf. In the Middle Ages they were called “palma Christi”, “hand of Christ’ because of their resemblance to a hand. Male and female flowers lack petals and are borne in terminal panicles with female flowers at the top and male flowers below in mid- to late summer. The male flowers have conspicuous yellow anthers while the female flowers have conspicuous red stigmas. The fruit is a spiny ovoid capsule that explosively releases three flattened ripe seeds that resemble ticks.
Scholars disagree on the identification of the plant, Hebrew kikaion, mentioned in Jonah 4.6; many believe that the plant was castor bean while a few others favor gourd. Jonah’s description of the plant favors castor bean as does the presence of castor beans in 5000 year-old Egyptian tombs and the fact that the plant grows wild in Israel today.
Jonah 4.6 (NIV) Jonah, angry at God for being compasionate towards the Ninevehites, sat watching Ninevh to see if the citizens returned to their evil ways.
“Then the LORD God provided a leafy plant and made it grow up over Jonah to give shade for his head to ease his discomfort, and Jonah was very happy about the plant.”
Castor bean likes full sun and average, moist, wel-drained soil in USDA Hardiness zones 8-11, but tolerates some drought once established. It is propagated by seed and has no significant pests or diseases. Although a perennial in warm climates, castor bean is widely grown as an annual in cooler climates where it can add a tropical look to the landscape. All parts of the plant especially the seeds are highly toxic so the plants should not be grown where children are likely to have access to them.
The genus name, Ricinus, is the classical Latin word meaning tick and refers to the appearance of the seeds. The genus name, communis, is the classical Latin word meaning common and refers to the distribution of the plant.