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Ricinus communis

Higher Taxonomy
Family: EuphorbiaceaeView DescriptionDichotomous Key

Habit: Annual to shrub, tree [vine, cactus-like succulent]; monoecious or dioecious; sap clear or milky. Stem: generally branched [fleshy or spiny]. Leaf: generally simple, alternate to whorled, generally stipuled, sessile or petioled; blade entire, toothed, or lobed. Inflorescence: flowers solitary or in terminal or axillary cymes, racemes, spikes, or panicles, or (in Euphorbia) 1° inflorescence a compact, flower-like cyathium with much-reduced flowers enclosed within an involucre of fused bracts, cyathia terminal or axillary, 1 or in cyme-like arrays. Flower: unisexual, +- radial; sepals 0 or 2--6, free or fused; petals generally 0(5); stamens 1--many, free or filaments fused; ovary superior, chambers (1)3(4), styles free or fused, undivided, forked, or variously lobed. Fruit: generally capsule that splits into mericarps that then dehisce, releasing seeds. Seed: 1 per chamber; knob-like appendage sometimes present at attachment scar.
Genera In Family: 217 genera, 6000+ species: +- worldwide especially tropics; some cultivated (Aleurites, tung oil; Euphorbia species; Hevea, rubber; Ricinus). Toxicity: Many species +- highly TOXIC, due primarily to latex, especially if eaten or in contact with skin, eyes. Note: Eremocarpus moved to Croton, Tetracoccus moved to Picrodendraceae for TJM2; Chamaesyce moved to Euphorbia here (key to genera revised by Thomas J. Rosatti).
eFlora Treatment Author: Mark H. Mayfield & Grady L. Webster, except as noted
Scientific Editor: Bruce G. Baldwin.
Genus: RicinusView Description 

Common Name: CASTOR BEAN

Species In Genus: 1 sp. Etymology: (Latin: tick, from seed shape)

Ricinus communis L.
Habit: Shrub, occasionally tree-like, 1--3 m, +- glabrous; sap clear; monoecious. Stem: trunk ascending to erect, branched above. Leaf: cauline, alternate, peltate; stipules fused, 1--1.5 cm, sheath-like, deciduous; petiole 1--3 dm, glandular distally; blade 1--5 dm, +- round, palmately 7--11-lobed, sharply toothed. Inflorescence: panicle, terminal, 1--3 dm; staminate flowers proximal to pistillate flowers. Staminate Flower: sepals 3--5; stamens many, clustered; nectary 0. Pistillate Flower: sepals 3--5; ovary 3-chambered, bristly, styles 2-lobed, plumose, +- red. Fruit: 1.2--2 cm diam, +- spiny. Seed: 9--22 mm, smooth, shiny, mottled; scar appendaged. Chromosomes: 2n=20.
Ecology: Disturbed areas; Elevation: < 300 m. Bioregional Distribution: GV, CCo, SCo, expected elsewhere; Distribution Outside California: eastern United States; native to Europe. Toxicity: Highly TOXIC: seeds attractive to children, fatal when ingested. Flowering Time: All year
eFlora Treatment Author: Mark H. Mayfield & Grady L. Webster
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botanical illustration including Ricinus communis


Citation for this treatment: Mark H. Mayfield & Grady L. Webster 2016. Ricinus communis, in Jepson Flora Project (eds.) Jepson eFlora,, accessed on February 13, 2016.

Citation for the whole project: Jepson Flora Project (eds.) 2016. Jepson eFlora,, accessed on February 13, 2016.

Ricinus communis
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© 2010 Neal Kramer
Ricinus communis
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© 2011 Neal Kramer
Ricinus communis
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© 2009 Thomas Stoughton
Ricinus communis
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© 2010 Neal Kramer
Ricinus communis
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© 2013 Keir Morse
Ricinus communis
click for enlargement
© 2010 Neal Kramer

More photos of Ricinus communis in CalPhotos

Geographic subdivisions for Ricinus communis:
GV, CCo, SCo, expected elsewhere;
Markers link to CCH specimen records. If the markers are obscured, reload the page [or change window size and reload]. Yellow markers indicate records that may provide evidence for eFlora range revision or may have georeferencing or identification issues.
map of distribution 1
(Note: any qualifiers in the taxon distribution description, such as 'northern', 'southern', 'adjacent' etc., are not reflected in the map above, and in some cases indication of a taxon in a subdivision is based on a single collection or author-verified occurence).

View elevation by latitude chart
Data provided by the participants of the Consortium of California Herbaria.
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CCH collections by month

Duplicates counted once; synonyms included.
Species do not include records of infraspecific taxa.
Blue line denotes eFlora flowering time.