CASTOR BEAN TREE

Along with gems, precious metals and other artifacts, archeologists who first went into 4,000-year-old Egyptian tombs discovered objects that looked like polished bits of marble. A closer look showed the objects to be seeds from the castor bean plant.

A native of Africa, the castor bean plant has become naturalized in warm areas throughout the world. In Southern California, Ricinus communis grows abundantly as a tree-like shrub in fields and along roadsides in the coastal sage scrub plant community. Pictured is a castor bean shrub in the Santa Monica Mountains.

The ancient Egyptians used oil derived from the plant’s beans as fuel for their lamps. It wasn’t until the late 18th Century that Europeans and Americans began using the oil from the castor bean as the foul-tasting laxative that children learned to hate.

Unless ricin is extracted from the oil, however, the castor bean is a deadly poison. A child can die from eating a single bean.

Nature-lovers sometimes find the plant’s large-lobed leaves so bold and striking that they cultivate the castor bean in their gardens. The leaves are 1 to 3 feet wide on young plants, smaller on older ones.

The plant can grow to 15 feet in seasons in which there have been plenty of sunshine, heat and moisture. Small white flowers, which grow in clusters on foot-long stalks, turn into prickly round husks during the late summer and early fall. These husks contain the seeds or beans.

Castor bean plants are members of the spurge family. In Africa, they are more tree-like and reach heights up to 40 feet. Other species produce rubber, tapioca, other oils and cassava. Oil from the castor bean also is used in hydraulic brake fluids, biodegradable laundry detergents, paints and varishes.