The sacred and the deadly

In the King James Version of The Holy Bible, Jonah finds himself scorching as the sun beats down upon his head. Jonah 4:6 reads: “And the Lord God prepared a gourd, and made it to come up over Jonah, that it might be a shadow over his head, to deliver him from his grief. So Jonah was exceeding glad of the gourd.” (It should be noted that in the spirit of the long-suffering hero’s whole saga, a worm eats through the stem the next morning, and Jonah is back under a hot desert sun once again.)

Many biblical scholars believe that Jonah’s “gourd” was in reality the castor bean — because it grows so quickly and its large, attractive leaves provide great shade. This plant has a long recorded history — its seeds, in fact, have been found in ancient Egyptian sarcophagi, where they were placed so they could accompany the dead on their voyage through the Land of Shades.

The scientific name is Ricinus communis, and the plant was first described and named by Linnaeus. The popular name stems from a mistake made by English traders who mistook the plant for another species, the chaste tree or monk’s pepper tree (Vitex agnus-castus), known in Jamaica as “agno-casto.”

The name chosen by Linnaeus is far more imaginative and should be readily comprehensible to anyone who’s ever seen the seed and/or served as dinner for a tick. Because the plant was so prevalent in tropical regions, the species is communis, meaning “common” in Latin. But Ricinus (“tick” in Latin) reflects the pioneering botanist’s sense of humor: He must have enjoyed naming a popular plant after its mottled seed’s close resemblance to a tick engorged with blood.

Castor has enjoyed many uses since ancient times, both in Egypt and in Persia, Africa, Greece, Rome and elsewhere. The oil produced by the plant was known as “palma Christi” (the “palm of Christ”), because the leaf is palmate in shape. Castor is considered by most authorities to be native to tropical Africa and may have originated in Abyssinia.

The stalked leaves consist of usually eight radiating, pointed leaflets with slightly serrated edges and prominent central veins. Many varieties are green, but some are reddish-brown. The flowers are generally green and inconspicuous, but pink or red in the pigmented varieties. Many stamens are near the base, and the branching pistils occur near the top of the flower. The soft-spiny fruits contain those mottled seeds that are such a distinctive feature of the plant.

Although commonly called a “bean,” castor plants are not legumes. Four thousand years ago, the Egyptians used castor oil in lamps, and it remains one of the oldest known commercial products.

Castor oil was used therapeutically in ancient India. Today it is used as an emollient and skin softener, and as a treatment for gastrointestinal problems, lacerations and other skin disorders (such as psoriasis). It’s also found in many skin-care products.

It should also be noted that a chemical called ricin, extracted from castor beans, is one of the most potent poisons on earth. Stores of ricin were recently found in a London flat rented by suspected terrorists.

In 1988, Bulgarian journalist Georgi Markov was assassinated in London by being prodded with an umbrella. The umbrella had a tiny ball coated with ricin on its tip, which lodged in the victim. He died in hospital a few days later.