Ricinus communis

A fast-growing evergreen shrub reaching 1.5 m tall by 1 m wide. Hardy to UK zone 9, frost-tender. In leaf year-round, flowering July to September, seeds ripening September to November. Monoecious and self-fertile, wind-pollinated. Grows in light sandy, medium loamy, and heavy clay soils, prefers well-drained conditions, tolerates heavy clay. Suitable for mildly acid, neutral, and basic soils. Requires full sun and moist soil.

Description

A small evergreen tree. Often they are grown as annual plants. It grows up to about 6 m high and spreads to 2 m across. The stem is erect, stout and branching. The plant can form suckers. It has leaves with pointy lobes spreading out like fingers on a hand. The leaves are large and glossy. The leaves are on long leaf stalks. The flowers are red and large and woolly. Female flowers are at the top and male flowers lower down. Clusters of flowers produce seed capsules containing 3 spiny seeds. Several different cultivated varieties exist which are chosen for their leaf and flower colour.

Edible Uses

The seed contains 35–55% of an edible oil used in cooking and is a rich source of phosphorus, 90% of which is in phytic form. Some caution is advised given the plant's toxicity.

Traditional Uses

People in many PNG villages claim to eat the seeds, cooked. Apparently some less poisonous kinds occur. The young leaves are cooked and eaten. The roots are also recorded as eaten raw. CAUTION The plant is normally recorded as deadly poisonous especially seeds, so should never be eaten raw. The poisons are destroyed by heat. An edible oil has been extracted from the plant. This must be refined before use. It is used for adding butter and nut flavours to foods including baked goods. The fruit are used for pickles. In India the young fruit are cooked as a vegetable. Young flowers are cooked as a vegetable.

Medicinal Uses

Castor oil, extracted from the seed, is a well-established laxative with over 2,000 years of use. It is regarded as fast, safe, and gentle, typically producing a bowel movement within 3–5 hours, and is recommended for use in both the very young and the elderly. It is effective enough to be used routinely to clear the digestive tract in cases of poisoning. It should not be used for chronic constipation, where it addresses symptoms without treating the underlying cause. The flavour is somewhat unpleasant and may cause nausea in some individuals. The oil has a notable antidandruff effect and is well tolerated by the skin, making it a useful vehicle for medicinal and cosmetic preparations. When an alcoholic solution of castor oil is distilled in the presence of sodium salts of higher fatty acids, it congeals into a gel useful for treating non-inflammatory skin diseases and providing protection against occupational eczema and dermatitis. The seed is anthelmintic, cathartic, emollient, laxative, and purgative. It is rubbed on the temples for headache and powdered for application to abscesses and skin infections. In Tibetan medicine the seed is considered to have an acrid, bitter, and sweet taste with a heating potency, and is used for indigestion and as a purgative. A decoction of the leaves and roots is antitussive, discutient, and expectorant. Leaves are used as a poultice to relieve headaches and treat boils.

Known Hazards

Ricinus is extremely allergenic, and has an OPALS allergy scale rating of 10 out of 10. The plant is also a very strong trigger for asthma, and allergies to Ricinus are commonplace and severe. The castor oil plant produces abundant amounts of very light pollen, which easily become airborne and can be inhaled into the lungs, triggering allergic reactions. The sap of the plant causes skin rashes. People who are allergic to the plant can also develop rashes from touching the leaves, flowers, or seeds. They can also have cross-allergic reactions to latex sap from the related Hevea brasiliensis plant. The toxicity of raw castor beans is due to the presence of ricin. Although the lethal dose in adults is considered to be four to eight seeds, reports of actual poisoning are relatively rare. According to the Guinness World Records, this is the world's most poisonous common plant. Ricin is also present in lower concentrations throughout the plant. If ricin is ingested, symptoms commonly begin within two to four hours, but may be delayed by up to 36 hours. These include a burning sensation in mouth and throat, abdominal pain, purging and bloody diarrhea. Within several days there is severe dehydration, a drop in blood pressure and a decrease in urine. Unless treated, death can be expected to occur within 3–5 days; however, in most cases a full recovery can be made. Poisoning occurs when animals, including humans, ingest broken castor beans or break the seed by chewing: intact seeds may pass through the digestive tract without releasing the toxin. The toxin provides the castor oil plant with some degree of natural protection from insect pests such as aphids. Ricin has been investigated for its potential use as an insecticide. Commercially available cold-pressed castor oil is not toxic to humans in normal doses, whether internal or external. As a non-freezing, antimicrobial, pressure-resistant lubricant for special purposes, either of latex or metals, or as a lubricating component of fuels. As sources of various chemical feedstocks. As a raw material for some varieties of biodiesel. As attractively patterned, low-cost personal adornments, such as non-durable necklaces and bracelets. Holes must not be drilled in the beans to make beads. The outer shell protects the wearer from the poison. Wearing castor beans has been known to cause rashes, and worse. As a component of many cosmetics. As an anti-microbial. The high percentage of ricinoleic acid residues in castor oil and its derivatives, inhibits many microbes, whether viral, bacterial or fungal. They accordingly are useful components of many ointments and similar preparations. As the major raw material (in oil form) for polyglycerol polyricinoleate, a modifier that improves the flow characteristics of cocoa butter in the manufacture of chocolate bars, and thereby reduces the costs. As a repellent for moles and voles in lawns.

Distribution

A tropical plant. It occurs throughout the country of Papua New Guinea up to about 2000 m altitude. It does well in humid areas but needs a well drained soil. It is tolerant to drought and light frost. It needs an open sunny position. It suits hardiness zones 9-12. In Yunnan.

Where It Grows

Africa, Algeria, American Samoa, Angola, Argentina, Aruba, Asia, Australia, Balkans, Bangladesh, Belize, Benin, Bhutan, Botswana, Brazil, Britain, Bulgaria, Burkina Faso, Burundi, Cambodia, Cameroon, Canary Islands, Central Africa, Central African Republic, CAR, Central America, Central Asia, Chad, Chile, China, Colombia, Congo DR, Costa Rica, Côte d'Ivoire, Cuba, Cyprus, Djibouti, Dominican Republic, East Africa*, East Timor, Ecuador, Egypt, El Salvador, Eritrea, Eswatini, Ethiopia*, Europe, Fiji, France, Gabon, Ghana, Guiana, Guianas, Guinea, Guinée, Guinea-Bissau, Himalayas, India, Indochina, Indonesia, Iran, Iraq, Israel, Italy, Ivory Coast, Japan, Jordan, Kenya, Korea, Lebanon, Lesotho, Liberia, Libya, Luxembourg, Macedonia, Malawi, Malaysia, Maldives, Mali, Marquesas, Mauritania, Mediterranean, Mexico, Middle East, Morocco, Mozambique, Myanmar, Namibia, Nepal, New Caledonia, New Zealand, Niger, Nigeria, Niue, Norfolk Island, North Africa, North America, Northeastern India, Oman, Pacific, Pakistan, Palestine, Papua New Guinea, PNG, Portugal, Rwanda, Sahara, Samoa, Saudi Arabia, SE Asia, Senegal, Serbia, Seychelles, Sierra Leone, Somalia, South Africa, Southern Africa, South America, Spain, Sri Lanka, St Helena, Sudan, Suriname, Swaziland, Syria, Tajikistan, Tasmania, Tanzania, Thailand, Timor-Leste, Togo, Tunisia, Turkey, Türkiye, Uganda, United Arab Emirates, UAE, Uruguay, USA, Vanuatu, Venezuela, West Africa, West Indies, Yemen, Zambia, Zimbabwe,

Cultivation

Prefers a well-drained moisture retentive clay or sandy loam in full sun. Requires a rich soil and daytime temperatures above 20°c for the seedlings to grow well, though the seed may fail to set if temperatures rise above 38°C for an extended period. The plant requires 140 - 180 days of warm temperatures in the growing season in order to produce good crops of seed, and is readily killed by frost. The plant is reported to tolerate an annual precipitation in the range of 20 to 429cm, an annual temperature in the range of 7.0 to 27.8°C and a pH of 4.5 to 8.3. The castor-oil plant is a fast-growing shrub in the wild, reaching up to 12 metres in height, though it is much smaller when cultivated in the temperate zone. A very ornamental plant, although it is not winter hardy in Britain, it can be grown outdoors as an annual bedding plant for sub-tropical displays, and can flower and produce fruit in its first year in warm summers. It has been known to ripen a crop of seeds as far north as Christiana in Norway. Providing the plants water needs are met, yields of around 1 tonne per hectare have been achieved, with exceptional cases of up t 5 tonnes per hectare. It has a long history of cultivation as an oil-bearing and medicinal plant, having been grown in ancient Egypt. It is still widely cultivated for its seed in tropical and sub-tropical zones. There are many named varieties, some developed for ornamental use and others for oil production. Plants may need support in exposed areas.

Propagation

Sow seed in early spring in a warm greenhouse, in individual pots. When large enough to handle, prick seedlings out into individual pots and plant out after the last expected frosts. Seed retains viability for 2–3 years.

Other Uses

The seed contains 35–55% of a drying oil used not only in cooking but also as an ingredient in soaps, polishes, flypapers, paints, and varnishes, and as a lubricant, lighting fuel, and component of precision engine fuels. It is used to coat fabrics and protective coverings, in high-grade lubricant manufacture, in transparent typewriter and printing inks, and in textile dyeing — when converted into sulfonated castor oil (Turkey-Red Oil) it is used to dye cotton fabrics with alizarin. It is also used in producing 'Rilson', a polyamide nylon-type fibre. The dehydrated oil is an excellent drying agent comparable to tung oil, used in paints and varnishes. Hydrogenated castor oil is used in waxes, polishes, carbon paper, candles, and crayons. A fibre for rope-making is obtained from the stems; cellulose from the stems is also used for cardboard and paper. The growing plant is said to repel flies, mosquitoes, moles, and nibbling insects. The leaves have insecticidal properties.

Production

Plants are fast growing. On poor soils plants produce flowers rather than leaves.

Other Information

A moderately common plant reportedly eaten in several places in Papua New Guinea. Normally it is considered very poisonous. It is cultivated.

Notes

There is only one Ricinus species. It can be invasive. The poison ricin in the seeds in soluble in water and not in the processed oil.

Synonyms

Also Known As

Aamanaka, Ander, Arind, Boliyr, Bonobono, Butsu kasrael, Dan-khra, Dantha, Endaru, Guloo, Higuereta, Higuerilla, Jarak, Khrwia, Kobo, Lumono, Mahung, Mpuluka, Mufuta, Palma cristi, Reri, Ricino, Varenda, Veron, Woalime gol

References (80)

• Achigan-Dako, E, et al (Eds), 2009, Catalogue of Traditional Vegetables in Benin. International Foundation for Science.
• Addis, G., et al, 2005, Ethnobotanical Study of Edible Wild Plants in Some Selected Districts of Ethiopia. Human Ecology, Vol. 33, No. 1, pp. 83-118
• Al-Sodany, Y. M., et al, 2013, Medicinal Plants in Saudi Arabia: I. Sarrwat Mountains at Taif, KSA. Academic Journal of Plant Sciences 6 (4): 134-145
• Ambasta S.P. (Ed.), 2000, The Useful Plants of India. CSIR India. p 526
• Aparicio, H., et al, 2021, Ethnobotanical study of medicinal and edible plants used in Nhamacoa area, Manica province
  -Mozambique. South African Journal of Botany 139 (2021) 318
  -328

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