Kauaʻi record · kba_plant_ricinus_communis
Castor bean
Ricinus communis
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About Castor bean
Castor bean (Ricinus communis) is an introduced tree treated as naturalized on Kauaʻi by Bishop Museum’s 2025 checklist and the 2026 Smithsonian checklist. Current extent is unassessed. A shrub or tree of seasonally dry tropical settings. Kauaʻi naturalization is explicitly documented at island level by the Bishop Museum 2025 checklist and corroborated by the Smithsonian 2026 checklist; this profile does not infer local abundance or impact.
Kauaʻi evidence
Taxonomic identity, tree form, diagnostic morphology and island occurrence use the linked reviewed sources. Historical planting, cultivation, naturalization and invasive status are separate. Generated imagery is not occurrence evidence.
Names and classification
- Scientific name
- Ricinus communis
- Common names
- Castor bean · Castor-oil plant
- Other names
- Ricinus communis · Castor bean · Castor-oil plant
- Record type
- Species
Kauaʻi occurrence and status
- Kauaʻi occurrence
- Recorded on Kauaʻi
- Origin
- Introduced
- Conservation status
- Not yet assessed
- Evidence date
- 2026-10-06
- Evidence limits
- Current abundance, stand extent, and fine distribution on Kauaʻi were not assessed; public scope remains island-only.
Habitat and ecology
- Habitats
- Not yet assessed
- Food and resource needs
- Not yet assessed
- Reproduction
- Monoecious: separate staminate and pistillate flowers occur on the same inflorescence, normally with male flowers below and female flowers above. Three-lobed capsules mature around mottled seeds.
- Shelter
- Not yet assessed
- Growth form
- Tree; Shrub
Threats and conservation
- Monitoring
- Not yet assessed
- Data gaps
- Current population extent and trajectory · Additional species-specific ecological and conservation sources
Process and seasonal context
- Seasonal timing
- Not yet assessed
- Seasonal description
- Castor bean (Ricinus communis) is an introduced tree treated as naturalized on Kauaʻi by Bishop Museum’s 2025 checklist and the 2026 Smithsonian checklist. Current extent is unassessed. A shrub or tree of seasonally dry tropical settings. Kauaʻi naturalization is explicitly documented at island level by the Bishop Museum 2025 checklist and corroborated by the Smithsonian 2026 checklist; this profile does not infer local abundance or impact.
Sources and further reading
- https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:355498-1
- https://hbs.bishopmuseum.org/publications/pdf/tr75.pdf
- https://doi.org/10.5479/si.32124043
- https://www.efloras.org/florataxon.aspx?flora_id=2&taxon_id=200012604
- https://www.efloras.org/florataxon.aspx?flora_id=5&taxon_id=200012604
- https://www.efloras.org/florataxon.aspx?flora_id=5&taxon_id=128572
- https://www.efloras.org/florataxon.aspx?flora_id=2&taxon_id=128572