Kauaʻi record · kba_plant_cajanus_cajan
Pigeon pea
Cajanus cajan
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About Pigeon pea
Pigeon pea (Cajanus cajan) is recorded as an established shrub on Kauaʻi. A shrub reaching about four metres, with ridged young stems and golden hairs. Each leaf has three leaflets, often silvery hairy beneath. Pea-shaped yellow flowers may show red or purple externally. Hairy pods contain several variable-colored seeds. A nitrogen-fixing shrub documented as naturalized on Kauai. Root-nodule symbiosis can contribute nitrogen to soils; Plant Pono describes it as unlikely to be invasive. No landscape-scale Kauai enrichment or damage is inferred.
Kauaʻi evidence
Established island occurrence follows the Bishop Museum checklist. Diagnostic morphology follows Smithsonian Hawaiian Flora; accepted identity follows Kew WCVP. Generated imagery is not occurrence evidence. Proposed monitoring endpoints are not reported observations, measured effects or causal findings.
Names and classification
- Scientific name
- Cajanus cajan
- Common names
- pigeon pea · red gram
- Hawaiian names
- pī nūnū
- Other names
- Cajanus cajan · pigeon pea · red gram · pī nūnū · Cajanum thora · Cajanus bicolor · Cajanus cajan f. bicolor · Cajanus cajan var. bicolor · Cajanus cajan var. flavus · Cajanus indicus var. bicolor · Cajanus indicus var. flavus · Cajanus indicus var. maculatus · Cajanus luteus · Cajanus obcordifolia · Cajanus pseudocajan · Cajanus striatus · Cytisus cajan · Cytisus guineensis · Cytisus mollis · Cytisus pseudocajan
- Record type
- Species
Kauaʻi occurrence and status
- Kauaʻi occurrence
- Recorded on Kauaʻi
- Origin
- Introduced
- Conservation status
- Not yet assessed
- Evidence date
- 2026-10-07
- Evidence limits
- Current extent and island effect sizes are unassessed. Public occurrence remains island-level only.
Habitat and ecology
- Habitats
- Disturbed open vegetation
- Food and resource needs
- Not yet assessed
- Reproduction
- Local pollinators, flowering schedules, seedling establishment and recruitment rates are not independently assessed.
- Shelter
- Not yet assessed
- Growth form
- Shrub or subshrub
Threats and conservation
- Monitoring
- Naturally recruiting shrubs and occupied area; Root nodulation and foliar nitrogen; Soil available nitrogen and plant cover in comparison plots. Proposed monitoring endpoints are not reported observations, measured effects or causal findings.
- Data gaps
- Current island population extent and trend · Quantified local environmental effects
Process and seasonal context
- Seasonal timing
- Not yet assessed
- Seasonal description
- Pigeon pea (Cajanus cajan) is recorded as an established shrub on Kauaʻi. A shrub reaching about four metres, with ridged young stems and golden hairs. Each leaf has three leaflets, often silvery hairy beneath. Pea-shaped yellow flowers may show red or purple externally. Hairy pods contain several variable-colored seeds. A nitrogen-fixing shrub documented as naturalized on Kauai. Root-nodule symbiosis can contribute nitrogen to soils; Plant Pono describes it as unlikely to be invasive. No landscape-scale Kauai enrichment or damage is inferred.
Sources and further reading
- https://naturalhistory2.si.edu/botany/hawaiianflora/speciesdescr.cfm?genus=Cajanus&species=cajan
- https://powo.science.kew.org/taxon/1152177-2
- https://hbs.bishopmuseum.org/publications/pdf/tr75.pdf
- https://plantpono.org/pono-plants/cajanus-cajan-pigeon-pea/
- https://plantpono.org/nitrogen-fixing-pono-hawaii/