Castor is a small annual plant. It ranges from 1 to 7 meters in height. It has well-developed roots, with green and reddish stems which become hollow with age.

The fruit is a spherical capsule with small grey seeds with brown spots.

Castor seeds were an important item of commerce in ancient Egypt. It has been found in tombs dating from 4000 BC. In India too, castor has been used since ancient times. In the Susruta Atharvaveda, dating back to 2000 BC, it is referred to as indigenous plant and that its oil was used for lamps. Two varieties--the red and the white seeded-are mentioned. The oil was, and is still, used extensively in local medicines mainly as a laxative, but also to soften dry and coarse skin. The Chinese have used the oil for medicinal purposes, for centuries.

The castor plant appears to have originated in eastern¬ Africa, especially around Ethiopia. It now grows throughout the warm-temperate and tropical regions and flourishes under a variety of climatic conditions. It can be grown almost anywhere and this is one of castor's greatest virtues.

The seeds of the plant contain alkoloid ricinine and toxalbumine ricin. They yield a fixed oil, which is used chiefly for medicinal purposes. Though castor plant or its oil is not a food, yet it is one of the m'ost commonly used oils allover the world as a safe purgative and drug for reducing irritation of the skin and alleviating swelling and pain.

Castor oil chiefly consists of ricinoleate of glycerol or triricinolein with a small quantity of palmitin and stearin. Unlike most fixed oils, castor oil possesses the remarkable property of mixing with absolute alcohol and glacial acetic acid in all proportions. The glycerides of ricinoleic acid in castor oil are mainly responsible for its purgative effect.

Castor is cultivated for the commercial importance of its oil. India is the world leader in castor seed and oil production and dominates the international castor oil trade.

The world castor seed production fluctuates between 12 to 18 lakh tons. India is major producer with 64 % share, followed by China and Brazil with 23 % and 7 % share respectively.

The Indian variety of castor has 48 % oil content of which 42% can be extracted, while the cake retains the rest. India's castor production fluctuates between 6 to 9 lakh tons a year. In 2003-04, India's castor production was 8.04 lakh tons.

Gujarat accounts for 86% of India's castor seed production followed by Andhra Pradesh and Rajasthan. Castor is mainly grown in Mehsana, Banaskantha and Saurashtra/Kutch regions of Gujarat and Nalgonda and Mahboobnagar districts of Andhra Pradesh.

Castor is a Kharif crop. The sowing season of castor is from July to October and the harvesting season is from October to April.

India annually exports around 2.0 - 2.4 lakh tons of commercial castor oil, 50,000 - 60,000 tons of castor seed extractions and 15,000 - 20,000 tons of castor seed.

While 90 % of castor seed and oil in India is produced in Gujarat and Andhra Pradesh, the domestic consumption is dispersed all across the country. Castor seed and oil are also exported to various countries, especially European Union, US and Japan.