Family: Fabaceae

A woody shrub that grows up to 5 feet. Indigofera suffruticosa, commonly called upright indigo, was introduced to Hawai’i by Dr. Serriere in 1836. Imported from Java, he grew and used the upright indigo to make dye. By all accounts, his indigo dye was of good quality. Upright indigo was already considered a weed by 1915 naturalists. Today, the shrub persists and spreads in dry, highly disturbed areas.

Description and Dispersal:

• A woody shrub growing up to 5 feet tall
  
• Pinnate leaflets of 10
  
• Leaflets are arranged opposite
  
• Terminal leaflet present
  
• Underside of the leaf are white hairs
  
• Classic pea family flowers are pink to red
  
• Pods are slightly curved upwards
  
• Human dispersed

High Risk Traits:

• Naturalized outside native range (Hawaii, Pacific islands)
  
• Agricultural weed (Puerto Rico, Trinidad, Vanuatu)
  
• Major environmental weed (Tonga)
  
• Forms dense, fire-prone thickets
  
• Tolerates wide range of soil types
  
• Self-pollinating; viable seed with high germination (>90%)
  
• Short generation time (can grow as annual)
  
• Prolific seed production (~257,000 seeds/kg)
  
• Persistent hard-seed bank
  
• Tolerates mutilation, grazing, and fire
  
• Nitrogen-fixing

Low Risk Traits:

• No spines, thorns, or burrs
  
• No allelopathy or parasitism
  
• Palatable to grazing animals
  
• Not toxic to humans
  
• Not shade tolerant
  
• Not climbing or smothering
  
• No vegetative fragmentation
  
• No wind, water, bird, or external animal dispersal
  
• Controlled by herbicides