Ricinus

Distinguished from other Euphorbiaceae by the combination of large palmately lobed leaves, terminal racemose inflorescences with separate male and female flowers, and spiny three-lobed capsules containing three large mottled seeds with caruncles. The 'false castor oil plant' Fatsia japonica (Araliaceae) is not closely related and differs in leaf structure and fruit type. Within Euphorbiaceae, Ricinus is placed in its own subtribe Ricininae based on unique morphological and chemical characteristics including the production of ricin and castor oil with high ricinoleic acid content.

Native to warm temperate and tropical regions; thrives in disturbed habitats, wastelands, and open areas. In tropical climates, establishes readily and can become invasive. Grown extensively as an ornamental in parks and public areas, and as a crop in agricultural systems. Requires well-drained soils and full sun; not cold hardy, suffering frost damage below freezing temperatures.

Indigenous to the southeastern Mediterranean Basin, East Africa, and India. Naturalized and widespread throughout tropical regions worldwide. Cultivated globally in suitable climates including southern Europe, the Americas, Africa, and Asia. In the United States, grows wild in parts of the Southwest and California, notably in Griffith Park, Los Angeles.

In temperate regions, active growth occurs during warm months; flowers and fruits produced summer through fall. In tropical climates, perennial with year-round growth potential. In frost-prone areas, grown as annual or overwintered in protected conditions.

• Ariadne merione - host plantCommon castor butterfly
• Samia cynthia ricini - host plantEri silkmoth
• Achaea janata - host plantCastor semi-looper moth
• Hypercompe hambletoni - host plantLepidopteran larval food plant
• Discestra trifolii - host plantNutmoth, larval food plant
• Evarcha culicivora - associationJumping spider consumes nectar and uses plant for courtship
• Ants (various species) - mutualismMyrmecochory via caruncle (elaiosome) on seeds

Perennial in tropical climates, behaving as annual in temperate regions with frost. Reproduces via mixed pollination system favoring selfing by geitonogamy while capable of outcrossing via wind (anemophily) or insect (entomophily) pollination. Natural pollination rates range from 5–46%. Seeds dispersed by ants attracted to lipid-rich caruncle; after removing caruncle, ants discard seeds in favorable germination sites. Seeds germinate readily in warm conditions; growth rapid, with plants reaching 2–3 m in one year under optimal conditions.

Provides food and habitat for specialized herbivores including several Lepidoptera species. Seed dispersal mutualism with ants. Contains ricin, which provides natural protection against insect pests such as aphids and has been investigated as a potential insecticide. Allelopathic properties inhibit germination of competing plants such as lettuce and tomato. Invasive potential in disturbed tropical habitats where it can outcompete native vegetation.

Economically important crop for castor oil production, with global production around two million tons annually; India produces over three-quarters of global yield. Oil used in lubricants, biodiesel, cosmetics, pharmaceuticals, and as chemical feedstock. Polyglycerol polyricinoleate derived from castor oil modifies cocoa butter flow in chocolate manufacture. Ornamental cultivars widely planted for foliage and architectural form. Historical medicinal use as laxative and topical treatment. Highly toxic: seeds contain ricin, one of the most potent plant toxins known; lethal dose in adults estimated at 4–8 seeds. Extremely allergenic (OPALS rating 10/10), with pollen, sap, and plant parts causing severe allergic reactions and asthma triggers. Misuse as instrument of coercion in historical political repression. Jewelry made from seeds poses poisoning risk if shells are damaged.

• Fatsia japonicaCommon name 'false castor oil plant' refers to superficial resemblance in leaf shape, but belongs to Araliaceae, not Euphorbiaceae; differs in palmate leaves with fewer, broader lobes, and berry-like fruits rather than spiny capsules
• Jatropha curcasAnother euphorb with toxic seeds and oil production potential; differs in smaller, less deeply lobed leaves, different inflorescence structure, and non-spiny capsules

• economic plant
• toxic plant
• oil crop
• ornamental
• invasive potential
• medicinal plant
• allelopathic

• BugGuide
• Wikipedia
• iNaturalist taxon
• NCBI Taxonomy
• Catalogue of Life
• What Eats Ticks? Study Puts an Old Technique to New Use
• Hemiptera | Beetles In The Bush | Page 9
• The Sweetest Snack: Research Details Mosquitoes' Nectar Preferences
• Un relato sonoro con higuerillas (Ricinus communis) A Sound Story with Castor Beans (Ricinus communis) Uma narrativa sonora com mamonas (Ricinus communis)
• Ticks ixodes ricinus (Linnaeus, 1758) Of the lower Dniester River
• Lipolytic activity of ricin from Ricinus sanguineus and Ricinus communis on neutral lipids
• Botany, Geographical Distribution, Cultivation Techniques, and Crop Productivity of Ricinus communis L.
• Review on Reproductive Biology of Caster bean (Ricinus communis L.)
• Diversity Assessment by Molecular Barcoding and Seed Morphology in Ricinus communis L.
• Effect of short and randomly oriented Ricinus Communis L (Castor oil) plant on Mechanical Behaviour of Ricinus Communis L/ Epoxy LY556 Composites
• Ricinus communis L. (MAMONA): Sementes Tóxicas Com Potencial Alelopático