Family: Araceae

Origin, Description & Uses
Xanthosoma robustum, commonly known as giant elephant ear, is native to Central Mexico and Central America. This large, tropical perennial is grown primarily for its impressive ornamental foliage, producing massive, upright, arrow-shaped leaves that create a bold landscape effect in gardens and around water features. It thrives in warm, moist environments with rich soils and partial shade but can also tolerate full sun with adequate moisture. While some species of Xanthosoma are cultivated as food crops for their edible corms, X. robustum is most commonly grown as an ornamental due to its striking appearance.

Risks & Threats
In Hawaiʻi, Xanthosoma robustum is naturalized on Kauaʻi, Oʻahu, Molokaʻi, Maui, and Hawaiʻi Island. It does possess traits that are cause for concern, including vigorous vegetative growth, the ability to spread from underground corms and plant fragments, and its tendency to form dense colonies in moist habitats. These characteristics can allow it to displace native vegetation and alter the structure of natural and riparian ecosystems. Although its overall invasive potential is still being evaluated, ongoing assessment is needed to better understand its impacts in Hawaiʻi. Because the species is already naturalized and capable of spreading beyond cultivation, caution is recommended when planting or disposing of garden waste to help ensure it does not negatively impact Hawaii’s native ecosystems.

High Risk Traits:

• Naturalized in the Hawaiian Islands (O'ahu, Molokai, Maui, and Hawai'i)
  
• Congeners are invasive weeds (Florida, Australia)
  
• Shade-tolerant (sun or partial shade)
  
• Geophyte with tubers; reproduces vegetatively (suckering, division)
  
• Produces viable seed
  
• Intentionally spread by people as an ornamental
  
• Tolerates mutilation; regrows from tuber pieces
  
• Persistent tuber bank (dormant over winter)

Low Risk Traits:

• Not a documented weed (agricultural, garden, or environmental)
  
• No spines, thorns, or burrs
  
• Not allelopathic, parasitic, or toxic to animals
  
• Narrow soil preference (fertile, well-drained, pH 5.5–6.5)
  
• Requires specialist pollinators (scarab beetles)