A perennial shrub that normally grows to 3 m tall but in suitable condition it grows as an evergreen tree and may reach up to 12 m height. In shrub form, stem is succulent with sap and in tree form it is woody, soft and light with central pith. Bark is light brown, smooth and exhibits rings at nodes. Leaves are large, 10 to 60 cm across, alternate in arrangement, palm like in shape with five to nine finger like lobes and sharply toothed leaf margin. Leaf stalk is long, attached to the centre of the leaf blade. Flowers are small and without corolla. Male and female flowers are on the same plant, and are produced on a clustered spike inflorescence, which is located at the end of the branches. Male flowers have greenish calyx, which is deeply cut into three to five segments and enclose numerous, much branched, yellow stamens. Male flowers are found in the lower portion of the flower head. Calyx of the female flower is slightly reddish in colour and cut into three segments. Fruit is a round capsule with soft prickles and deeply grooved. Each fruit contains three shiny, ovoid and tick-like seeds of variable colour.
Castor oil plant, Castorbean's Behavior & Ecology
It tolerates a wide variety of soil but performance is good in fertile, well-drained and neutral soil. Its tolerance to aerosol salt and salinity is low. It requires full sun and high temperature for better yield. It colonizes disturbed and wasted lands, where it grows rapidly, shading out native species and producing monospecific stands. It is cultivated as an oil crop and it is propagated entirely by seeds, which retain their viability for two to three years. Pretreated seeds to resist diseases are sown directly. Seedlings grown in nursery are also used to raise plantation. It exhausts soil nutrients easily and hence, application of fertilizers is necessary.
Castor oil plant, Castorbean's Relationship with Humans
Seeds yield fast-drying, non-yellowing oil, used mainly in industry and medicine. It is used as additives in paints and varnishes, in the manufacture of high-grade lubricants mainly for aircrafts, printing inks, in textile dyeing, in leather preservation and in the production of a nylon-type fibre. Oil and its derivatives are used as skin moisturizer and smoothing agents. Hydrogenated oil is utilized in the manufacture of waxes, polishes, carbon paper, candles and crayons. Seeds are highly toxic and the principal toxin is ricin.