Family: Euphorbiaceae

Origin, Description & Uses
Manihot esculenta (cassava) is a tropical shrub native to South America that is widely cultivated throughout the tropics for its large starchy roots. Also known as yuca or manioc, cassava is an important food crop in many parts of the world and is used to make flour, tapioca, and other staple foods. The plant has palmately divided leaves and can grow several feet tall in warm climates. In Hawai‘i, cassava is grown in home gardens, small farms, and cultural plantings for food, animal feed, and ornamental value.

Risks & Threats
Cassava is naturalized on Kaua‘i and O‘ahu and is potentially naturalizing on Maui and Hawai‘i Island. While it can reproduce and persist outside of cultivation in some areas, it is generally considered a low-risk species in Hawai‘i. Cassava does not appear to spread aggressively or form dense infestations that significantly disrupt native ecosystems. However, because it can survive from stem fragments and occasionally establish in disturbed areas, gardeners and land managers should monitor plantings and dispose of cuttings responsibly to help prevent unwanted spread.

High Risk Traits:

• Naturalized outside native range (including several Hawaiian Islands)
  
• Weedy races exist (can become a garden weed)
  
• Congeneric weeds (hybridizes with wild weedy relatives)
  
• Toxic to humans (contains HCN/prussic acid; requires processing)
  
• Forms persistent seed bank (>1 year)
  
• Tolerates mutilation (resprouts after repeated harvesting)
  
• Tolerates wide soil conditions (pH 4.5–8.7; various textures)
  
• Self-compatible & apomictic (reproduction possible without cross-pollination)

Low Risk Traits:

• Domesticated
  
• No spines, thorns, or burrs
  
• Not allelopathic or parasitic
  
• Palatable to grazing animals (leaves used as forage)
  
• Not a significant agricultural/environmental weed (no strong evidence)
  
• Low seed production