Family: Fabaceae
Origin, Description & Uses:
Leucaena diversifolia (diverseleaf leadtree, upland koa haole) is native to Mexico and Central America, where it grows in a variety of dry to moist tropical environments. It is a fast-growing small tree or large shrub in the legume family, often reaching several meters in height. Like other Leucaena species, it has feathery, bipinnate leaves and produces abundant pods containing seeds that are easily spread. It has been introduced to many tropical regions for use as a nitrogen-fixing shade tree, living fence, erosion control plant, and occasionally for forage and green manure due to its ability to improve soil fertility.
Risks & Threats:
In Hawaiʻi, Leucaena diversifolia is naturalized on Oʻahu and Maui, meaning it is already established in the wild and reproducing without cultivation. This species possesses traits that are cause for concern, including rapid growth, prolific seed production, and the ability to form dense stands that can outcompete and displace native vegetation. Like other leadtrees, it can alter soil chemistry through nitrogen fixation, potentially favoring other invasive species and changing ecosystem balance. These characteristics make it a potential threat to tropical island ecosystems, where it may reduce biodiversity and hinder native forest regeneration. Because of these risks, choosing a low-risk or native alternative is strongly recommended for planting in Hawaiʻi.
High Risk Traits:
- Thrives in higher elevation tropical climates
- Elevation range exceeds 1000 m
- Naturalized outside native range
- Related Leucaena species have become invasive
- Nitrogen fixing (may modify soil chemistry and facilitate invasions by other weeds)
- Seeds prolifically
- Hybridizes readily with other Leucaena species
- Self-compatible
- Coppices vigorously
- Movement of seeds likely aided by people, wind, and water
Low Risk Traits:
- Unarmed (no spines, thorns or burrs)
- Palatable to cattle and other grazing animals and used as a fodder tree at cooler, higher elevation areas
- May be Shade-intolerant
- Although naturalized, and possessing many weedy traits, no information has yet to be documented on invasive impacts of this species
