Archive for October 20, 2008

Monday, October 20, 2008

Arbor Mirabilis: Castor Bean

Stems and leaves of Ricinus communis

Above: Stems and leaves of Ricinus communis

Widely naturalized throughout the tropics, castor bean (Ricinus communis) is commonly grown as an ornamental annual in American and European gardens, but it is also a crop plant of worldwide economic importance. In a tropical environment, the castor bean attains the status of a thirty-foot tree. Even in temperate zones, it can reach a height of fifteen feet in a single season. An ancient medicinal plant of African origin, castor bean was employed by the Egyptians as a cathartic and is among the plant remedies found in the Ebers Papyrus.  Like other members of the Spurge family (Euphorbiaceae), the plant is poisonous. Dioscorides, writing in the first century, refers to the plant by its Egyptian name, kiki, as well as its Greek and Roman names: kroton and ricinus.  The last two names derive from the Greek and Latin words for “tick,”  because of a fancied resemblance of the seed to the parasite. Read more »