Family: Asteraceae

Gymnanthemum amygdalinum (bitterleaf) is an evergreen shrub or small tree native to Africa and South America. The young shoots and leaves are edible and can be added to soups. While the leaves often have an intensely bitter flavor, some varieties are nearly free of bitterness. Bitterleaf is traditionally used as medicine in Africa, with a wide range of applications. It is also cultivated as a hedge, living fence, and for erosion control. Though it is reported to be naturalized in India, there is no documentation of its naturalization on any Hawaiian Islands. This plant has toxic roots, produces numerous seeds that spread easily by wind and water, and can regrow after being cut back. These characteristics, along with its reputation as a crop weed in its native range, contribute to its high-risk rating for Hawaiʻi.

High Risk Traits:

• Elevation range exceeds 1000 m, demonstrating environmental versatility
  
• Grows in tropical climates
  
• Naturalized in India
  
• Reported to be a crop weed within native range
  
• Other species in the genus Vernonia are regarded as invasive; some treatments still include bitterleaf in this genus
  
• Roots reported to be toxic
  
• Tolerates many soil types
  
• Reproduces by seeds
  
• Seeds dispersed by wind, moved by water, and intentionally cultivated by people
  
• Prolific seed production
  
• Able to coppice after cutting

Low Risk Traits:

• Unarmed (no spines, thorns, or burrs)
  
• Provides fodder for livestock and edible leaves for human consumption (palatable despite reports of root toxicity)
  
• Requires full sunlight (dense shade may limit ability to spread)
  
• Not reported to spread vegetatively