Family: Fabaceae

Origin, Description & Uses
Inga laurina, commonly known as guama or sacky sac bean, is a small to medium-sized tropical tree native to parts of Central and South America. It typically grows in warm, humid environments and is recognized for its spreading canopy, feathery compound leaves, and elongated seed pods filled with a sweet, cottony pulp surrounding the seeds. The tree is often cultivated in agroforestry systems, home gardens, and plantations, where it is valued for its edible fruit, shade provision, and ability to improve soil fertility through nitrogen fixation. It is also used as a living fence, windbreak, and for erosion control, making it a versatile and beneficial species in tropical agriculture.

Risks & Threats
Although Inga laurina is not currently known to be naturalized in Hawaii, it possesses traits that raise concern for potential invasiveness. These include rapid growth, the ability to fix nitrogen and alter soil conditions, and production of seeds that may be dispersed by animals. Such characteristics could allow it to establish and spread in favorable environments, potentially outcompeting native vegetation and altering ecosystem processes. Because of these risks, caution is recommended when considering its introduction or cultivation. Ongoing evaluation is needed to determine whether this species could negatively impact Hawaii’s ecosystems.

High Risk Traits:

• Grows in tropical climates; naturalized outside native range (e.g., Cuba)
  
• Host for recognized pests/pathogens (e.g., coffee pests, mites)
  
• Shade tolerant (seedlings survive in light to medium shade)
  
• Tolerates wide range of soil conditions (sands to clays, low pH, poor drainage)
  
• Nitrogen-fixing (can alter soil nutrients)
  
• Produces viable seed
  
• Propagules dispersed intentionally by people (ornamental, shade, edible pulp)
  
• Dispersed by water, birds, bats, other animals (including external transport and gut passage)
  
• Tolerates mutilation (coppices when small)
  
• Relatively resistant to some herbicides

Low Risk Traits:

• No reports as a weed (garden, agricultural, or environmental)
  
• Unarmed (no spines, thorns, or burrs)
  
• Not allelopathic, parasitic, or toxic
  
• Palatable to livestock and wildlife
  
• Does not form dense thickets (low density in native forests)
  
• No prolific seed production
  
• No persistent seed bank (seeds cannot be stored; lose viability if dried)
  
• Limited vegetative reproduction (large trees do not coppice)