Kauaʻi record · kba_plant_casuarina_cunninghamiana_x_casuarina_glauca

River Oak × Swamp Oak Hybrid

Casuarina cunninghamiana × Casuarina glauca

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About River Oak × Swamp Oak Hybrid

River Oak × Swamp Oak Hybrid (Casuarina cunninghamiana × Casuarina glauca) is an introduced tree documented as naturalized on Kauaʻi by Bishop Museum’s 2025 checklist. An interspecific Casuarina hybrid between two eastern Australian trees. Its morphology and ecological behavior can vary with parentage and clone; the Hawaiian checklist treats the hybrid formula as a naturalized Kauaʻi concept. Naturalized on Kauaʻi in the Bishop Museum 2025 checklist (Status=nat; K=K); the screened Smithsonian 2026 name set did not provide an independent match; public occurrence is island-level only. This evidence does not quantify current abundance or ecological effects.

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: Casuarina cunninghamiana × Casuarina glauca
Common names: River Oak × Swamp Oak Hybrid · Hybrid she-oak
Other names: Casuarina cunninghamiana × Casuarina glauca · River oak × swamp oak hybrid · Hybrid she-oak
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 island-wide abundance, occupied habitat, reproductive distribution, population trend, and ecological effects on Kauaʻi remain unassessed.

Habitat and ecology

Habitats: Not yet assessed
Food and resource needs: Not yet assessed
Reproduction: Parent Casuarina taxa reproduce by wind-carried pollen and winged nuts, and C. glauca can also spread vegetatively by root suckers. Fertility and reproductive mode of the naturalized Kauaʻi hybrid population are not established, so neither seed production nor clonal spread should be assumed for every individual.
Shelter: Not yet assessed
Growth form: Tree; Interspecific hybrid

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: River Oak × Swamp Oak Hybrid (Casuarina cunninghamiana × Casuarina glauca) is an introduced tree documented as naturalized on Kauaʻi by Bishop Museum’s 2025 checklist. An interspecific Casuarina hybrid between two eastern Australian trees. Its morphology and ecological behavior can vary with parentage and clone; the Hawaiian checklist treats the hybrid formula as a naturalized Kauaʻi concept. Naturalized on Kauaʻi in the Bishop Museum 2025 checklist (Status=nat; K=K); the screened Smithsonian 2026 name set did not provide an independent match; public occurrence is island-level only. This evidence does not quantify current abundance or ecological effects.

Sources and further reading

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