Family: Malvaceae

Origin, Description & Uses
Ochroma pyramidale (balsa) is native to a wide region from southern Mexico through tropical Central and South America. It is a very fast-growing pioneer tree that thrives in warm, wet tropical climates and can quickly reach impressive heights, often emerging above surrounding vegetation. The tree is best known for its extremely lightweight wood, which is one of the lightest commercial timbers in the world. Because of this unique property, balsa wood is widely used in model building, crafts, lightweight construction materials, insulation, flotation devices, and specialty industrial applications where strength combined with low weight is important.

Risks & Threats
Although Ochroma pyramidale is not currently known to be naturalized in the Hawaiian Islands, it does possess traits that are cause for concern. Its rapid growth, high seed production, and ability to colonize disturbed sites could allow it to spread aggressively in suitable tropical environments. In other regions, it has the potential to form dense stands that compete with and displace native vegetation, particularly in areas affected by disturbance such as landslides, roadsides, or cleared land. Wind-dispersed seeds can also aid in its spread across open landscapes. Because of these characteristics, it could detrimentally impact tropical island ecosystems if it were to become established. When available, choosing low-risk or native plant alternatives is recommended to help protect Hawaii’s unique ecosystems.

High Risk Traits:

• Naturalized outside native range (e.g., Galapagos, Cameroon, Papua New Guinea)
  
• Documented as an invasive environmental weed (Galapagos)
  
• Broad climate suitability (environmentally versatile)
  
• Tolerates a wide range of soil conditions
  
• Produces viable seed
  
• Prolific seed production (400–600 seeds/pod; ~112,000–150,000 seeds/kg)
  
• Forms a persistent seed bank (orthodox seed storage)
  
• Wind-dispersed seeds (efficient long-distance dispersal)
  
• Intentionally introduced by people
  
• Host for recognized pests/pathogens (e.g., shot-hole borer, root disease fungus)

Low Risk Traits:

• No spines, thorns, or burrs
  
• Not toxic to animals or humans (no evidence)
  
• Not self-compatible (self-incompatible)
  
• Requires specialist pollinators (bats, insects)
  
• No vegetative fragmentation
  
• Does not tolerate deep shade (strong light demander)
  
• Susceptible to fire damage (roots easily damaged)