Latin Name: Ricinus Communis
Origin: Native to Africa and Eurasia
Known Hazards: Whole plant is very poisonous, even one seed has been known to be lethal to children. The seedcoat contains an extremely lethal poison that was once used by the KGB to dispose of their enemies. The leaves are only mildly poisonous. The toxic principle is water-soluble so is not found in the oil.
Habitat: Wastelands and disturbed soils.
Edibility Rating: 1 (1-5)
Medicinal Rating: 4 (1-5)
Physical Characteristics: Spreading shrub to about 6 m tall. Perennial in moist areas, annual in frosty areas. Roots thick and fibrous. Seed at first in a soft, spiny, green capsule that dries to reddish-brown; each capsule about 2 cm long. Seeds smooth, patterned black and fawn and to 1.7 cm long.
Distinguishing features: Distinguished by large palmately divided leaves, objectionable smell of leaves when crushed and hollow stems. Leaves to about 50 cm diameter when mature, with 7–9 lobes.
Dispersal: Seeds ejected explosively. Cultivated for castor oil.
Oil. The seed contains 35 – 55% of an edible oil, used in cooking. The seed is a rich source of phosphorus, 90% of which is in the phytic form. Some caution should be observed, see the notes above on toxicity
Anthelmintic; Antidandruff; Antitussive; Cathartic; Emollient; Expectorant; Laxative; Purgative; Skin. The oil from the seed is a very well-known laxative that has been widely used for over 2,000 years. It is considered to be fast, safe and gentle, prompting a bowel movement in 3 – 5 hours, and is recommended for both the very young and the aged. It is so effective that it is regularly used to clear the digestive tract in cases of poisoning. It should not be used in cases of chronic constipation, where it might deal with the symptoms but does not treat the cause. The flavour is somewhat unpleasant, however, and it can cause nausea in some people. The oil has a remarkable antidandruff effect. The oil is well-tolerated by the skin and so is sometimes used as a vehicle for medicinal and cosmetic preparations. Castor oil congeals to a gel-mass when the alcoholic solution is distilled in the presence of sodium salts of higher fatty acids. This gel is useful in the treatment of non-inflammatory skin diseases and is a good protective in cases of occupational eczema and dermatitis. The seed is anthelmintic, cathartic, emollient, laxative, purgative. It is rubbed on the temple to treat headache and is also powdered and applied to abscesses and various skin infections. The seed is used in Tibetan medicine, where it is considered to have an acrid, bitter and sweet taste with a heating potency. It is used in the treatment of indigestion and as a purgative. A decoction of the leaves and roots is antitussive, discutient and expectorant. The leaves are used as a poultice to relieve headaches and treat boils.
Fibre; Insecticide; Oil; Repellent. The seed contains 35 – 55% of a drying oil. As well as being used in cooking, it is an ingredient of soaps, polishes, flypapers, paints and varnishes. It is also used as a lubricant and for lighting and as an ingredient in fuels for precision engines. The oil is used in coating fabrics and other protective coverings, in the manufacture of high-grade lubricants, transparent typewriter and printing inks, in textile dyeing (when converted into sulfonated Castor Oil or Turkey-Red Oil, for dyeing cotton fabrics with alizarine) and in the production of ‘Rilson’, a polyamide nylon-type fibre. The dehydrated oil is an excellent drying agent which compares favorably with tung oil and is used in paints and varnishes. The hydrogenated oil is utilized in the manufacture of waxes, polishes, carbon paper, candles and crayons. A fibre for making ropes is obtained from the stems. The growing plant is said to repel flies and mosquitoes. When grown in the garden it is said to rid it of moles and nibbling insects. The leaves have insecticidal properties. Cellulose from the stems is used for making cardboard, paper etc.
Notes: Introduced to Australia and noted in records in 1803. Now in all States except Tasmania. Widespread and common in wasteland. Seedlings and juveniles grow rapidly. Castor oil is extracted from seeds. Seeds contain the toxin ricin. Toxicity to stock differs with the animal. Humans are sensitive to the toxin and a few seeds ingested may kill. Leaves are unpalatable and unlikely to be eaten by stock. Castor Oil Plant is scattered over the distribution shown on the map.