Family: Fabaceae

Origin, Description & Uses
Pongamia pinnata (Indian beech, pongamia) is a medium-sized, fast-growing tropical tree native to tropical and subtropical regions of Asia and the western Pacific. It is valued for its broad canopy, glossy green leaves, fragrant pink-to-white pea-like flowers, and tolerance of heat, drought, salinity, and poor soils. Pongamia has long been planted as a shade tree, windbreak, ornamental, and erosion-control species. Its seeds are rich in oil and are widely used in traditional applications including biofuel production, lamp oil, soaps, and natural pesticides. The tree is also used in agroforestry systems because it can improve soil fertility through nitrogen fixation.

Risks & Threats
Although Pongamia pinnata is currently not known to be naturalized in the Hawaiian Islands, it does possess traits that are cause for concern and which could detrimentally impact tropical island ecosystems. The species grows rapidly, produces abundant seeds, tolerates a wide range of environmental conditions, and can establish in disturbed coastal and lowland habitats. These characteristics increase its potential to spread beyond cultivation and compete with native vegetation. Its ability to form dense stands and alter soil conditions may negatively affect biodiversity and ecosystem function in sensitive island environments. Because of these concerns, Plant Pono recommends choosing a low-risk or native alternative when suitable options are available.

High Risk Traits:

• Broad climate suitability. Elevation range exceeds 1000 m, demonstrating environmental versatility
  
• Thrives in tropical climates
  
• Naturalized in Florida, Mauritius and possibly elsewhere (native range uncertain)
  
• Regarded as weedy and aggressive in Florida landscapes
  
• A potential agricultural and environmental weed (impacts unclear)
  
• Leaves and seeds potentially toxic to animals and people (although leaves used as fodder)
  
• Shade-tolerant (could potentially invade intact forest)
  
• Tolerates many soil types
  
• N-fixing (may alter soil chemistry)
  
• Reproduces by seeds and vegetatively by root suckers
  
• Self-compatible
  
• Seeds dispersed by water and intentionally by people
  
• Seeds able to be stored for extended periods; May form a persistent seed bank
  
• Able to coppice and resprout after cutting

Low Risk Traits:

• Despite reports of invasiveness, evidence of detrimental impacts in natural or agricultural settings is not well-documented in the peer-reviewed literature
  
• Unarmed (no spines, thorns, or burrs)
  
• Provides fodder for livestock (palatable despite reports of toxicity)
  
• Valuable as a biofuel feedstock
  
• Reaches maturity in 4-7 years
  
• Relatively large seed size may reduce risk of accidental or long-distance dispersal (especially if not grown near water or riparian areas)