Family: EUPHOBIACEAE
A large bush to small tree (0.9 - 4 m tall and spreading to 2 m), it does best in dry, hot regions with an annual average rainfall of 380 - 500 mm, and is frost and drought tolerant. It is adaptable to a wide range of soils but prefers coarse, open textured soils and grows poorly on badly drained or saline soils. It has become a common weed of the coastal area around Perth, Western Australia.
The seeds are poisonous to animals (including humans), but are the commercial source of castor oil. Oil content of seed varies between 35 - 55%. The oil is important in industry and pharmaceuticals. It does not solidify at low temperatures and retains its viscosity at high temperatures. It is a great lubricant and an important part of hydraulic fluids, and is a good oil for leather dressing to make it pliable and soft. It is used in the manufacture of soap, candles, hair oils, cosmetics, perfumes, fly paper and poison, typewriter ink, cutting oil, linoleum rubber substitutes and artificial leather. It is used in the manufacture of Roghan to make wax cloth and in the manufacture of Turkey red oil for dyeing and printing cotton and woollen fabrics. It is also used in the finishing of cotton, silk, linen and leather. It is used in wood oils. The natives of Ecuador string the seeds and burn them as candles. The oil cake is valued as a manure. The stems are good for paper making and the leaves are an important food of silkworm. It is a valued bee forage.
The cold drawn oil is regarded as one of the most valuable laxatives in medicine, but should not be used in cases of severe constipation. It is an effective purgative, an excellent evacuant for children, as an enema mixed with soapy water and is applied locally for conjunctivitis. It is dropped into the eye to relieve the irritation caused after removing foreign bodies. Mixed with citron ointment it is used as a topical application in common leprosy. The seed also contains ricin, a toxin which is a blood coagulant and an enzyme, lipase.
A poultice of the leaves can be applied to boils and swellings. Coated with a bland oil the hot leaves are applied across the abdomen of children to relieve flatulence, over the pubic area of women to promote menstruation, over the breasts to soothe inflammation during lactation, and over Guinea worm sore to remove the worm.
In narcotic poisoning, the juice of the leaves is given as an emetic. A leaf decoction is an emmenagogue, purgative and a lactagogue. The root is made into a paste and applied for tooth - ache, made into a decoction with added carbonate of potash to treat lumbago, rheumatism and sciatica. These last three ailments are also treated by giving a paste of the seed without the embryo and boiled in milk.