Family: Pittosporaceae
Origin, Description & Uses
Pittosporum undulatum (Australian cheesewood) is an evergreen tree native to southeastern Queensland and eastern Victoria in Australia. It is valued as an ornamental for its dense canopy, glossy wavy-edged leaves, fragrant white flowers, and bright orange fruits. The species is commonly planted in gardens, parks, and along roadsides because it grows quickly and tolerates a variety of environmental conditions. Its attractive appearance and adaptability have contributed to its widespread cultivation outside its native range.
Risks & Threats
In Hawai‘i, Pittosporum undulatum is naturalized on Lāna‘i, Maui, and Hawai‘i Island. This species possesses traits that are cause for concern, including rapid growth, prolific seed production, and the ability to spread into native forests. Birds readily disperse the seeds, allowing the tree to invade natural areas where it can form dense stands that shade out native plants and alter ecosystem structure. Because it is adapted to moist tropical and subtropical environments, it could detrimentally impact tropical island ecosystems by reducing native biodiversity and changing forest composition. Choosing a low risk or native alternative is recommended when suitable alternatives are available.
High Risk Traits:
- Broad climate adaptability (tropical to warm temperate)
- Naturalized on multiple continents & islands (including Lana'i, Maui and Hawai'i)
- Forms dense thickets, shades out native plants
- Environmental weed in forests & shrublands
- Tolerates shade and wide range of soils
- Produces viable seed; flowers in 4–5 years
- Hybridizes with native Pittosporum species
- Seeds bird-dispersed & survive gut passage
- Host for Phytophthora ramorum (pathogen)
- Resprouts after cutting or damage
Low Risk Traits:
- No spines, thorns, or burrs
- No evidence of field allelopathy
- Not toxic to animals (used as fodder)
- No persistent soil seed bank
- Not wind- or water-dispersed
- Killed by intense fire
