Editing Ricinus

{{Short description|Monotypic genus of plant in the family Euphorbiaceae}}
{{For|the genus of lice|Ricinus (insect){{!}}''Ricinus'' (insect)}}
{{redirect-distinguish|Castor oil plant|False castor oil plant (disambiguation){{!}}False castor oil plant}}
{{Use dmy dates|date=September 2022}}
{{Speciesbox
|image = Ricinus March 2010-1.jpg
|image_caption = Leaves and inflorescence (male flowers below female flowers)
|display_parents = 4
|genus = Ricinus (plant)
|parent_authority = [[Carl Linnaeus|L.]]
|species = communis
|authority = L.
}}

'''''Ricinus communis''''', the '''castor bean'''<ref>{{PLANTS|id=RICO3|taxon=Ricinus communis|access-date=1 February 2016}}</ref> or '''castor oil plant''',<ref>{{cite web|title=''Ricinus communis'': Castor oil plant|url=https://herbaria.plants.ox.ac.uk/bol/plants400/profiles/QR/Ricinuscommunis|website=Oxford University Herbaria|publisher=Dept. of Plant Sciences, Oxford|quote=The castor oil plant is one of the few major crops to have an origin in Africa.}}</ref> is a species of [[perennial]] [[flowering plant]] in the [[Euphorbia|spurge]] family, [[Euphorbiaceae]]. It is the sole species in the [[Monotypic taxon|monotypic]] [[genus]], '''''Ricinus''''', and [[subtribe]], '''Ricininae'''. The evolution of castor and its relation to other species are currently being studied using modern genetic tools.<ref>{{cite web |url=http://www.igs.umaryland.edu/?q=content/euphorbiaceae-spurge-genomics |title=Euphorbiaceae (spurge) genomics |work=Institute for Genome Sciences |publisher=[[University of Maryland, Baltimore|University of Maryland Medical School]] |access-date=2009-03-09}}</ref> It reproduces with a mixed pollination system which favors selfing by [[geitonogamy]] but at the same time can be an out-crosser by [[anemophily]] (wind pollination) or [[entomophily]] (insect pollination).<ref name="ReferenceA">{{cite journal|last1=Rizzardo|first1=RA|last2=Milfont|first2=MO|last3=Silva|first3=EM|last4=Freitas|first4=BM|title=''Apis mellifera'' pollination improves agronomic productivity of anemophilous castor bean (''Ricinus communis'')|journal=Anais da Academia Brasileira de Ciências|date=December 2012|volume=84|issue=4|pages=1137–45|pmid=22990600|doi=10.1590/s0001-37652012005000057|doi-access=free}}</ref>

Its [[seed]] is the castor bean, which despite the term is not a [[bean]] (as it is not the seed of a member of the family [[Fabaceae]]). Castor is indigenous to the southeastern [[Mediterranean Basin]], [[East Africa]], and [[India]], but is widespread throughout tropical regions (and widely grown elsewhere as an ornamental plant).<ref name="Phillips">{{cite book |last1=Phillips |first1=Roger |title=Annuals and Biennials |last2=Rix |first2=Martyn |publisher=Macmillan |year=1999 |isbn=978-0-333-74889-3 |location=London |page=106}}</ref>

Castor seed is the source of [[castor oil]], which has a wide variety of uses. The seeds contain between 40% and 60% oil that is rich in [[triglyceride]]s, mainly [[ricinolein]]. The [[Seed#Structure|seed]] also contains [[ricin]], a highly potent [[Hydrophile|water-soluble]] [[toxin]], which is also present in lower concentrations throughout the plant {{citation needed|date=May 2024}}.

The plant known as "false castor oil plant", ''[[Fatsia japonica]]'', is not closely related.

==Description==
''Ricinus communis'' can vary greatly in its growth habit and appearance. The variability has been increased by breeders who have selected a range of cultivars for leaf and flower colours, and for oil production. It is a fast-growing, [[Basal shoot|suckering]] [[shrub]] that can reach the size of a small tree, around {{convert|12|m|ft|abbr=off}}, but it is not [[Hardiness (plants)|cold hardy]].

The glossy [[Leaf|leaves]] are {{convert|15|–|45|cm|in|abbr=off|0}} long, long-stalked, alternate and palmate with five to twelve deep lobes with coarsely toothed segments. In some varieties they start off dark reddish purple or bronze when young, gradually changing to a dark green, sometimes with a reddish tinge, as they mature. The leaves of some other varieties are green practically from the beginning, whereas in yet others a pigment masks the green color of all the [[chlorophyll]]-bearing parts, leaves, stems and young fruit, so that they remain a dramatic purple-to-reddish-brown throughout the life of the plant. Plants with the dark leaves can be found growing next to those with green leaves, so there is most likely only a single gene controlling the production of the pigment in some varieties.<ref>e.g. {{cite web |url=http://database.prota.org/publishedspeciesEn.htm |title=PROTA published species |access-date=2010-04-21 |url-status=dead |archive-url=https://web.archive.org/web/20100504125220/http://database.prota.org/publishedspeciesEn.htm |archive-date=4 May 2010 }}</ref> The stems and the spherical, spiny seed capsules also vary in pigmentation. The fruit capsules of some varieties are more showy than the flowers.

The flowers lack petals and are unisexual (male and female) where both types are borne on the same plant ([[Plant sexuality#Individual plant sexuality|monoecious]]) in terminal [[panicle]]-like [[inflorescence]]s of green or, in some varieties, shades of red. The male flowers are numerous, yellowish-green with prominent creamy [[stamen]]s; the female flowers, borne at the tips of the spikes, lie within the immature spiny capsules, are relatively few in number and have prominent red [[stigma (flower)|stigmas]].<ref name="Brickell">{{cite book |editor=Christopher Brickell |title=The Royal Horticultural Society A-Z Encyclopedia of Garden Plants |year=1996 |pages=884–885 |publisher=[[Dorling Kindersley]] |location=London |isbn=978-0-7513-0303-2}}</ref>

The fruit is a spiny, greenish (to reddish-purple) [[Capsule (botany)|capsule]] containing large, oval, shiny, bean-like, highly poisonous seeds with variable brownish mottling. Castor seeds have a warty appendage called the [[Elaiosome|caruncle]], which is a type of [[elaiosome]]. The caruncle promotes the dispersal of the seed by ants (myrmecochory).

{{gallery|mode=packed
|Ricin commun.jpg|Young plant
|Ricinus communis DSC 0022.JPG|Green variant after blooming, with developing seed capsules
|Leaf of Castor bean plant.jpg|Leaf
|Ricinus communis (male) - Flickr - Kevin Thiele.jpg|Male flower
|Pollen Ricinus communis sanguineus.jpg|Pollen grains of ''Ricinus communis''
|Ricinus communis (female) - Flickr - Kevin Thiele.jpg|Female flower
|Castor oil plant seeds.jpg|The green capsule dries and splits into three sections, forcibly ejecting seeds
|Seeds of Ricinus communis.jpg|Seeds
|Castor bean young with teething leaves.jpg|[[Cotyledons]] (round) and first true leaves (serrated) on a young plant (about four weeks old)
}}

=== Chemistry ===
Three [[terpenoid]]s and a [[tocopherol]]-related compound have been found in the aerial parts of ''Ricinus''. Compounds named (3''E'',7''Z'',11''E'')-19-hydroxycasba-3,7,11-trien-5-one, 6α-hydroxy-10β-methoxy-7α,8α-epoxy-5-oxocasbane-20,10-olide, 15α-hydroxylup-20(29)-en-3-one, and (2''R'',4a''R'',8a''R'')-3,4,4a,8a-tetrahydro-4a-hydroxy-2,6,7,8a-tetramethyl-2-(4,8, 12-trimethyltridecyl)-2''H''-chromene-5,8-dione were isolated from the methanol extracts of ''Ricinus communis'' by chromatographic methods.<ref>{{cite journal |author1=Tan Q.-G. |author2=Cai X.-H. |author3=Dua Z.-Z. |author4=Luo X.-D. |year=2009 |title=Three terpenoids and a tocopherol-related compound from ''Ricinus communis'' |journal=[[Helvetica Chimica Acta]] |volume=92 |issue=12 |pages=2762–8 |doi=10.1002/hlca.200900105}}</ref>
Partitioned h-hexane fraction of ''Ricinus'' root methanol extract resulted in enrichment of two triterpenes: lupeol and urs-6-ene-3,16-dione (erandone). Crude methanolic extract, enriched n-hexane fraction and isolates at doses 100&nbsp;mg/kg p.o. exhibited significant (P < 0.001) anti-inflammatory activity in carrageenan-induced hind paw oedema model.<ref>{{cite journal |last1=Srivastava |first1=Pooja |last2=Jyotshna |last3=Gupta |first3=Namita |last4=Kumar Maurya |first4=Anil |last5=Shanker |first5=Karuna |year=2013 |title=New anti-inflammatory triterpene from the root of Ricinus communis |journal=Natural Product Research |volume=28 |issue=5 |pages=306–311 |doi=10.1080/14786419.2013.861834 |pmid=24279342 |s2cid=36797216}}</ref>

== Etymology ==
[[Carl Linnaeus]] used the name ''Ricinus'' because it is a [[Latin]] word for [[tick]]; the seed is so named because it has markings and a bump at the end that resemble certain ticks. The genus ''[[Ricinus (insect)|Ricinus]]''<ref>Charles de Geer, 1752-1778 ''[http://visualiseur.bnf.fr/CadresFenetre?O=NUMM-97151&M=pagination&Y=Image Mémoires pour servir à l'histoire des insectes]'', digital facsimile at the [[Gallica]] website.</ref> also exists in zoology, and designates insects (not ticks) which are parasites of birds; this is possible because the names of animals and plants are governed by different [[nomenclature codes]].<ref>{{Cite journal |last1=Oliver |first1=Paul M. |last2=Lee |first2=Michael S.Y. |date=2010 |title=The botanical and zoological codes impede biodiversity research by discouraging publication of unnamed new species |journal=Taxon |volume=59 |issue=4 |pages=1201–1205 |doi=10.1002/tax.594020 |issn=0040-0262}}</ref><ref>{{Cite web |title=Animal Nomenclature |url=https://projects.ncsu.edu/cals/course/zo150/mozley/nomencla.html |access-date=2020-08-04 |website=projects.ncsu.edu}}</ref>

The common name "castor oil" probably comes from its use as a replacement for [[castoreum]], a perfume base made from the dried [[perineum|perineal glands]] of the [[beaver]] (''castor'' in Latin).<ref>{{cite web |title=The Complex Case of Castor's Etymology |url=http://www.billcasselman.com/cwod_archive/beaver_castor_two.htm |url-status=usurped |archive-url=https://web.archive.org/web/20110203042939/http://www.billcasselman.com/cwod_archive/beaver_castor_two.htm |archive-date=3 February 2011}}</ref> It has another common name, '''palm of Christ''', or ''Palma Christi'', that derives from castor oil's reputed ability to heal wounds and cure ailments.

== Ecology ==
[[File:Castor bean in distubred area.jpg|thumb|Plant in disturbed area]]

''Ricinus communis'' is the host plant of the common castor butterfly (''[[Ariadne merione]]''), the eri silkmoth (''[[Samia cynthia|Samia cynthia ricini]]''), and the castor semi-looper moth (''[[Achaea janata]]''). It is also used as a food plant by the [[larva]]e of some other species of [[Lepidoptera]], including ''[[Hypercompe hambletoni]]'' and the nutmeg (''[[Discestra trifolii]]''). A jumping spider ''[[Evarcha culicivora]]'' has an association with ''R. communis''. They consume the nectar for food and preferentially use these plants as a location for courtship.<ref name="Cross-2009">Cross, Fiona R., and Robert R. Jackson. "Odour‐mediated response to plants by evarcha culicivora, a blood‐feeding jumping spider from East Africa." New Zealand Journal of Zoology 36.2 (2009): 75-80.</ref>

Each castor seed has a yellow nodule full of fats one end of the seed that are nutritious for young ants. After hauling their harvest into their nests and pulling off the delicious part, ants discard the rest of the seed into their trash pile, where the future plant starts to grow.{{Citation needed|date=January 2024}}

== Cultivation ==
[[File:Ricinus communis4.jpg|thumb|In Greece it is hardy enough to grow as a small tree. In northern countries it is grown instead as an [[Annual plant|annual]].]]

Although ''Ricinus communis'' is indigenous to the southeastern [[Mediterranean Basin]], [[Eastern Africa]], and India, today it is widespread throughout tropical regions.<ref name="Phillips" /> In areas with a suitable climate, castor establishes itself easily where it can become an invasive plant and can often be found on wasteland.

It is also used extensively as a decorative plant in parks and other public areas, particularly as a "dot plant" in traditional [[Bedding (horticulture)|bedding schemes]]. If sown early, under glass, and kept at a temperature of around {{convert|20|°C|°F}} until planted out, the castor oil plant can reach a height of {{convert|2|–|3|m|ft}} in a year. In areas prone to [[frost]] it is usually shorter, and grown as if it were an [[annual plant|annual]].<ref name="Phillips" /> However, it can grow well outdoors in cooler climates, at least in southern England, and the leaves do not appear to suffer frost damage in sheltered spots, where it remains evergreen.<ref>{{Cite web |title=Castor Bean, Ricinus communis |url=https://wimastergardener.org/article/castor-bean-ricinus-communis/ |access-date=2020-08-04 |website=Master Gardener Program |language=en-US}}</ref> It was used in Edwardian times in the parks of Toronto, Canada. Although not cultivated there, the plant grows wild in the US, notably [[Griffith Park]] in Los Angeles.<ref>''Toronto Star'', 9 June 1906, p.&nbsp;17</ref> <!-- not sure what the following sentence meant, as there is no "white" variety or cultivar: Of the red and white variety, the red is seen as an ornamental plant, the white is used medicinally.-->

===Cultivars===
[[Cultivar]]s have been developed  by breeders for use as ornamental plants (heights refer to plants grown as annuals) and for commercial production of castor oil.<ref name="Brickell" />

;Ornamental cultivars
*'Carmencita' has gained the [[Royal Horticultural Society]]'s [[Award of Garden Merit]]<ref name="RHSPF">{{cite web |title=RHS Plantfinder – ''Ricinus communis'' 'Carmencita' |url=https://www.rhs.org.uk/Plants/106235/i-Ricinus-communis-i-Carmencita/Details |access-date=9 October 2018}}</ref><ref>{{cite web |date=July 2017 |title=AGM Plants – Ornamental |url=https://www.rhs.org.uk/plants/pdfs/agm-lists/agm-ornamentals.pdf |access-date=9 October 2018 |publisher=Royal Horticultural Society |page=88}}</ref> 
* 'Carmencita Bright Red' has red stems, dark purplish leaves and red seed pods;
* 'Carmencita Pink' has green leaves and pink seed pods
* 'Gibsonii' has red-tinged leaves with reddish veins and bright scarlet seed pods
* 'New Zealand Purple' has plum colored leaves tinged with red, plum colored seed pods turn to red as they ripen
*: (All the above grow to around {{convert|1.5|m|ft}} tall as annuals.)<ref name="Phillips" />
* 'Impala' is compact (only {{convert|1.2|m|ft|disp=or}} tall) with reddish foliage and stems, brightest on the young shoots
* 'Red Spire' is tall ({{convert|2|–|3|m|ft|disp=or}}) with red stems and bronze foliage
* 'Zanzibarensis' is also tall ({{convert|2|–|3|m|ft|disp=or}}), with large, mid-green leaves ({{convert|50|cm|in|disp=or}} long) that have white midribs<ref name="Brickell" />

;Cultivars for oil production
* 'Hale' was launched in the 1970s for the US state of Texas.<ref>{{cite book |url=https://books.google.com/books?id=oEcUAQAAMAAJ |title=The Cattleman |year=1961 |page=126 |quote="Hale" is a dwarf-internode castor bean variety developed in the cooperative castorbean program of the [[United States Department of Agriculture]] and the [[Texas Agricultural Experiment Station]]. It is resistant to bacterial [[leaf spot]] and ''[[Alternaria]]'' leaf spot}}</ref> It is short (up to {{convert|1.2|m|disp=or|abbr=on}}) and has several racemes
* 'Brigham' is a variety with reduced ricin content adapted for Texas, US. It grows up to {{convert|1.8|m|abbr=on}} and has 10% of the ricin content of 'Hale'
* 'BRS Nordestina' was developed by Brazil's [[Embrapa]] in 1990 for hand harvest and semi-arid environments
* 'BRS Energia" was developed by Embrapa in 2004 for mechanised or hand harvest
* 'GCH6' was developed by [[Sardarkrushinagar Dantiwada University]], India, 2004: it is resistant to root rot and tolerant to [[fusarium wilt]]
* 'GCH5' was developed by Sardarkrushinagar Dantiwada University, 1995. It is resistant to fusarium wilt
* 'Abaro' was developed by the [[Ethiopian Institute of Agricultural Research]]'s Essential Oils Research Center for hand harvest
* 'Hiruy' was developed by the Ethiopian Institute of Agricultural Research's [[Awash Melkasa|Melkassa]] and [[Wondo Genet]] Agricultural Research Centers for hand harvest during 2010/2011

== Allergenicity and toxicity ==
''Ricinus'' is extremely allergenic, and has an [[OPALS (Ogren Plant Allergy Scale)|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.<ref name="Ogren">{{cite book |last1=Ogren |first1=Thomas |title=The Allergy-Fighting Garden |date=2015 |publisher=Ten Speed Press |isbn=978-1-60774-491-7 |location=Berkeley, CA |pages=184–185}}</ref>

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.<ref name="Ogren" />

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.<ref>{{cite journal |vauthors=Wedin GP, Neal JS, Everson GW, Krenzelok EP |date=May 1986 |title=Castor bean poisoning |journal=Am J Emerg Med |volume=4 |issue=3 |pages=259–61 |doi=10.1016/0735-6757(86)90080-X |pmid=3964368}}</ref> According to the ''[[Guinness World Records]]'', this is the world's most poisonous common plant.<ref>{{cite book |title=Guinness World Records 2017 |date=2016 |publisher=Guinness World Records Limited |location=London, UK |page=43}}</ref>

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.<ref name="Soto-Blanco">{{cite journal |vauthors=Soto-Blanco B, Sinhorini IL, Gorniak SL, Schumaher-Henrique B |date=June 2002 |title=''Ricinus communis'' cake poisoning in a dog |journal=Vet Hum Toxicol |volume=44 |issue=3 |pages=155–6 |pmid=12046967}}</ref><ref>''Ricinus communis'' (Castor bean)—[[Cornell University]] 2008. {{cite web |title=Castorbean |url=http://www.ansci.cornell.edu/plants/castorbean.html |url-status=dead |archive-url=https://web.archive.org/web/19980508072815/http://www.ansci.cornell.edu/plants/castorbean.html |archive-date=8 May 1998}}</ref>

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.<ref name="Soto-Blanco" /> The toxin provides the castor oil plant with some degree of natural protection from insect pests such as [[aphid]]s. Ricin has been investigated for its potential use as an [[insecticide]].<ref name="Ombrello">[http://faculty.ucc.edu/biology-ombrello/POW/castor_bean.htm Union County College: Biology: Plant of the Week: Castor Bean Plant] {{webarchive|url=https://web.archive.org/web/20130524162501/http://faculty.ucc.edu/biology-ombrello/POW/castor_bean.htm|date=24 May 2013}}</ref>

Commercially available cold-pressed castor oil is not toxic to humans in normal doses, whether internal or external.<ref>{{cite journal |author=Irwin R |date=March 1982 |title=NTP technical report on the toxicity studies of Castor Oil (CAS No. 8001-79-4) In F344/N Rats And B6C3F1 Mice (Dosed Feed Studies) |journal=Toxic Rep Ser |volume=12 |pages=1–B5 |pmid=12209174}}</ref>

== Uses ==

=== Folk medicine ===
Castor oil and the plant's roots and leaves are used in the ancient Indian medicinal system of [[Ayurveda]].

=== Modern commercial usage ===
{{Main|Castor oil}}

Global castor seed production is around two million tons per year. Leading producing areas are India (with over three-quarters of the global yield), China and Mozambique, and it is widely grown as a crop in Ethiopia. There are several active breeding programmes.

{| class="wikitable"
|-
|+Top ten castor oil seed producers – 2019
|-
! Country
! Production ([[tonne]]s)
! Footnote
|-
| India || align="right" |1,196,680 || align="right" |
|-
| Mozambique || align="right" |85,089 || align="right" | F
|-
| China || align="right" |36,000 || align="right" | *
|-
| Brazil || align="right" |16,349 || align="right" |
|-
| Ethiopia || align="right" |11,157 || align="right" | *
|-
| Vietnam || align="right" |7,000 || align="right" | *
|-
| South Africa || align="right" |6,721 || align="right" | F
|-
| Paraguay || align="right" |6,000 || align="right" | *
|-
| Thailand || align="right" |1,588 || align="right" | *
|-
| Pakistan || align="right" |1,107 || align="right" | *
|-
| bgcolor="#cccccc" |{{noflag}}'''World'''
| bgcolor="#cccccc" align="right" | '''1,407,588 '''
| bgcolor="#cccccc" align="right" | '''A'''
|-
| colspan="5" |No symbol = official figure, F = FAO estimate,<br>* = Unofficial/Semi-official/mirror data,<br>A = Aggregate (may include official, semi-official or estimates)
|}

Other modern uses of natural, blended, or chemically altered castor products include:
* As a non-freezing, [[antimicrobial]], pressure-resistant lubricant for special purposes, either of latex or metals, or as a lubricating component of fuels.<ref name="MortierOrszulik2012">{{cite book |author1=R. M. Mortier |url=https://books.google.com/books?id=uKKNBwAAQBAJ&pg=PA226 |title=Chemistry and Technology of Lubricants |author2=S. T. Orszulik |date=6 December 2012 |publisher=Springer |isbn=978-1-4615-3272-9 |pages=226–}}</ref>
* As sources of various chemical [[feedstock]]s.<ref>[http://www.castoroilworld.com/castor-crop-information/ Castor Oil World]</ref>
* 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 castors 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 bar]]s, and thereby reduces the costs.
* As a repellent for [[mole (animal)|mole]]s and [[vole]]s in lawns.

=== Historical usage ===
==== Ancient uses ====
Castor seeds have been found in [[Ancient Egypt|Egyptian]] tombs dating back to 4000 BC; the slow-burning oil was mostly used to fuel lamps. [[Herodotus]] and other [[Ancient Greece|Greek]] travellers noted the use of castor seed oil for lighting, body ointments, and improving hair growth and texture. [[Cleopatra]] is reputed to have used it to brighten the whites of her eyes. The [[Ebers Papyrus]] is an ancient Egyptian medical treatise believed to date from 1552 BC. Translated in 1872, it describes castor oil as a [[laxative]].<ref>{{cite journal |last1=Tunaru |first1=S |last2=Althoff |first2=TF |last3=Nusing |first3=RM |last4=Diener |first4=M |last5=Offermanns |first5=S |year=2012 |title=Castor Oil Induces Laxation and Uterus Contraction via Ricinoleic Acid Activating Prostaglandin EP3 Receptors |journal=Proceedings of the National Academy of Sciences of the United States of America |volume=109 |issue=23 |pages=9179–9184 |bibcode=2012PNAS..109.9179T |doi=10.1073/pnas.1201627109 |pmc=3384204 |pmid=22615395 |doi-access=free}}</ref>

The use of castor bean oil (''eranda'') in India has been documented since 2000 BC in lamps and in local medicine as a laxative, [[purgative]], and [[cathartic]] in [[Unani]], [[Ayurvedic]], [[siddha]] and other [[ethnomedical]] systems. Traditional Ayurvedic and [[siddha medicine]] considers castor oil the king of medicinals for curing [[arthritis|arthritic diseases]]. It is regularly given to children to treat infections with parasitic worms.<ref>{{Cite journal |last=Rekha |first=D. |date=2013 |title=Study of medicinal plants used from koothanoallur and marakkadai, Thiruvarur district of Tamil Nadu, India. |journal=Hygeia Journal for Drugs and Medicines |volume=5 |issue=1 |pages=164–170}}</ref>

The ancient Romans had a variety of medicinal/cosmetic uses for both the seeds and the leaves of ''Ricinus communis''. The naturalist [[Pliny the Elder]] cited the poisonous qualities of the seeds, but mentioned that they could be used to form wicks for oil lamps (possibly if crushed together), and the oil for use as a laxative and lamp oil.<ref>{{cite news |author=John Bostock & H.T. Riley |year=1855 |title=Pliny, the Natural History Chapter 41. – Castor Oil, 16 Remedies |url=https://www.perseus.tufts.edu/hopper/text?doc=Perseus%3Atext%3A1999.02.0137%3Abook%3D23%3Achapter%3D41}}</ref> He also recommends the use of the leaves as follows:

{{blockquote|"The leaves are applied topically with vinegar for [[erysipelas]], and fresh-gathered, they are used by themselves for diseases of the mamillæ [breasts] and de- fluxions; a decoction of them in wine, with [[polenta]] and [[saffron]], is good for inflammations of various kinds. Boiled by themselves, and applied to the face for three successive days, they improve the complexion."<ref>{{cite book| title=Natural History| author=Pliny the Elder| page=Chapter 41, Book 23.41}}</ref>}}

In [[Haiti]] it is called ''maskreti'',<ref>{{cite book |url=https://books.google.com/books?id=OeA1-Of-LscC&pg=PA347 |title=Guide to Afro-Cuban Herbalism |year=2009 |isbn=9781438980973 |editor=Quiros-Moran, Dalia |page=347 |publisher=AuthorHouse |access-date=5 August 2017}}</ref> where the plant is turned into a red oil that is then given to newborns as a [[purgative]] to cleanse the insides of their first stools.<ref>{{cite book |url=https://books.google.com/books?id=FelsAAAAMAAJ&q=maskreti+newborn+haiti |title=Comprehensive Maternity Nursing: Perinatal and Women's Health |year=1990 |isbn=9780867204216 |editor1=Auvenshine, Martha Ann |page=122 |publisher=Jones and Bartlett Publishers |access-date=5 August 2017 |editor2=Enriquez, Martha Gunther}}</ref>

Castor seed and its oil have also been used in China for centuries, mainly prescribed in local medicine for internal use or use in dressings.<ref>{{Cite journal |last1=Scarpa |first1=Antonio |last2=Guerci |first2=Antonio |date=1982 |title=Various uses of the castor oil plant (Ricinus communis L.) a review |journal=Journal of Ethnopharmacology |volume=5 |issue=2 |pages=117–137 |doi=10.1016/0378-8741(82)90038-1 |issn=0378-8741 |pmid=7035750}}</ref>

==== Uses in punishment ====
{{further|Castor oil#Punishment}}
Castor oil was used as an instrument of coercion by the paramilitary [[Blackshirts]] under the regime of [[Italian Fascism|Italian]] dictator [[Benito Mussolini]] and by the [[Civil Guard (Spain)|Spanish Civil Guard]] in Francoist Spain. Dissidents and regime opponents were forced to ingest the oil in large amounts, triggering severe [[diarrhea]] and [[dehydration]], which could ultimately cause death. This punishment method was originally thought of by [[Gabriele D'Annunzio]], the Italian poet and Fascist supporter, during the [[First World War]].<ref>{{Citation |last=Petersen |first=Jens |title=Violence in Italian Fascism, 1919–25 |date=1982 |work=Social Protest, Violence and Terror in Nineteenth- and Twentieth-century Europe |pages=275–299 |place=London |publisher=Palgrave Macmillan UK |doi=10.1007/978-1-349-16941-2_17 |isbn=978-1-349-16943-6}}</ref>

=== Other uses ===
Extract of  ''Ricinus communis'' exhibited [[acaricide|acaricidal]] and [[insecticide|insecticidal]] activities against the adult of ''[[Haemaphysalis bispinosa]]'' ([[Acarina]]: [[Ixodidae]]) and [[hematophagous]] fly ''[[Hippobosca maculata]]'' ([[Diptera]]: [[Hippoboscidae]]).<ref>{{cite journal |vauthors=Zahir AA, Rahuman AA, Bagavan A |title=Evaluation of botanical extracts against ''Haemaphysalis bispinosa'' Neumann and ''Hippobosca maculata'' Leach |journal=Parasitology Research |volume=107 |issue=3 |pages=585–92 |date=August 2010 |pmid=20467752 |doi=10.1007/s00436-010-1898-7 |s2cid=20498642 |display-authors=etal}}</ref>

Members of the Bodo tribe of [[Bodoland]] in [[Assam]], India, use the leaves of the plant to feed the [[larva]]e of [[Muga silk|muga]] and [[Eri silk|endi]] [[silkworm]]s.

Castor oil is an effective motor lubricant and has been used in [[internal combustion engine]]s, including those of [[World War I]] airplanes, some racing cars and some [[model airplanes]]. It has historically been popular for lubricating [[two-stroke engines]] due to high resistance to heat compared to petroleum-based oils. It does not mix well with petroleum products, particularly at low temperatures, but mixes better with the methanol-based fuels used in [[Glow plug (model engine)|glow model engines]]. In [[Total-loss oiling system|total-loss-lubrication]] applications, it tends to leave carbon deposits and varnish within the engine. It has been largely replaced by synthetic oils that are more stable and less toxic.

[[Jewellery]] can be made of castor beans, particularly necklaces and bracelets.<ref name="Dogs" /> Holes must not be drilled into the castor beans as the shell protects the wearer from the ricin.{{Citation needed|date=January 2024}}  Any chips in the shell can cause poisoning of the wearer.{{Citation needed|date=January 2024}}  Pets who chew the jewellery can become ill.<ref name="Dogs">{{Cite web | url=http://www.nbcnews.com/id/31130769/ns/health-pet_health/t/growing-danger-toxic-plants-pose-pet-threat/#.VEOiHxaNrIU | archive-url=https://web.archive.org/web/20140511004106/http://www.nbcnews.com/id/31130769/ns/health-pet_health/t/growing-danger-toxic-plants-pose-pet-threat#.VEOiHxaNrIU | url-status=dead | archive-date=11 May 2014 | title=Growing danger: Toxic plants pose pet threat| website=[[NBC News]]| date=2009-06-10}}</ref>

''Ricinus communis''  leaves are used in botanical printing (also known as ecoprinting) in Asia. When bundled with cotton or silk fabric and steamed, the leaves can produce a green-colored imprint.<ref>{{Citation |title=how to make ECOPRINT DIY | date=3 September 2019 |url=https://www.youtube.com/watch?v=F7zPTcR1bFE |language=en |access-date=2022-10-23}}</ref>{{Better source needed|reason=YouTube not a reliable source|date=October 2022}}

==See also==
* [[Kikayon]]
* [[Toxalbumin]]

==References==
{{reflist}}

==Further reading==
* {{Cite book |last1=Everitt |first1=J.H. |last2=Lonard |first2=R.L. |last3=Little |first3=C.R.|title=Weeds in South Texas and Northern Mexico |publisher=Texas Tech University Press |location=Lubbock |year=2007 |isbn=978-0-89672-614-7}}

==External links==
* [http://www.jatrophabiodiesel.org/castor/index.php A Bean Called Castor Can Cut Carbon & Fuel the Future]
* [http://www.hort.purdue.edu/newcrop/duke_energy/Ricinus_communis.html ''Ricinus communis L.'']&nbsp;– at Purdue University
* [http://www.hort.purdue.edu/newcrop/afcm/castor.html ''Castor beans'']&nbsp;– at Purdue University
* [https://web.archive.org/web/19980508072815/http://www.ansci.cornell.edu/plants/castorbean.html ''Ricinus communis'' (castor bean)] at Cornell University
* [http://www.wildflowers.co.il/english/plant.asp?ID=101 Ricinus communis] in Wildflowers of Israel
* [http://www.flowersinisrael.com/Ricinuscommunis_page.htm Castor oil plant] Flowers in Israel

{{Taxonbar|from1=Q9069137|from2=Q155867|from3=Q15633353}}
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[[Category:Crops originating from Africa]]
[[Category:Castor oil plant| ]]
[[Category:Acalypheae]]
[[Category:Monotypic Euphorbiaceae genera]]
[[Category:Taxa named by Carl Linnaeus]]
[[Category:Flora naturalised in Australia]]