ricinus

Ricinus, commonly known as the castor bean plant, is a genus in the spurge family (Euphorbiaceae) best known for Ricinus communis, the castor oil plant. It is cultivated worldwide for its ornamental value and, more importantly, for seeds from which castor oil is produced. The plant has many cultivars and forms, ranging from shrubs to small trees.

Description and ecology: Ricinus communis is a perennial that can grow as a shrub or small tree, often reaching several meters in height and sometimes more in ideal conditions. It features large, palmately lobed leaves typically divided into five to eleven leaflets, with a glossy green appearance. The plant produces panicles of insignificant flowers, followed by spiny capsules that house mottled seeds. Seeds contain the toxin ricin, though the oil extracted from the seeds does not carry the toxin in a usable form. The species tolerates a range of soils and climates but is not frost-tolerant; it is common in tropical and subtropical regions and can become invasive outside its native range.

Distribution and use: Native to southeastern Africa, Ricinus communis is now naturalized in many tropical and subtropical countries. It is grown as an ornamental plant in gardens and landscapes and as a source of castor oil, which has numerous industrial and pharmaceutical applications. Castor oil is extracted from the seeds; the refined oil is widely used in lubricants, cosmetics, and medicines, while the seed meal after detoxification may be used as fertilizer or feed under strict safety controls.

Toxicity and safety: The seeds contain ricin, a highly toxic protein, and ingestion or improper handling can be dangerous. Exposure through chewing or crushing seeds can be life-threatening; proper handling with gloves and keeping seeds away from children are advised. Castor oil itself, when properly processed, is not toxic.