Family: Poaceae

Origin, Description & Uses
Setaria palmifolia (palm grass) is native to Tropical and Subtropical Asia extending into eastern Australia. It is a robust, clumping perennial grass recognized for its striking, broad, pleated leaves that resemble small palm fronds, giving it its common name. The plant can form dense tufts in shaded to partially sunny conditions and thrives in moist environments. It has been introduced in many tropical regions as an ornamental species and has also been used locally for erosion control, ground cover, and occasionally as fodder or mulch material due to its high biomass production.

Risks & Threats
Setaria palmifolia is naturalized across all major Hawaiian Islands, including Kauaʻi, Oʻahu, Molokaʻi, Lānaʻi, Maui, and Hawaiʻi Island, and is often common in mesic valleys, wet forests, and along stream corridors. Its ability to form dense stands allows it to compete with and displace native understory vegetation, reducing habitat quality and hindering native plant regeneration. It can spread effectively in moist, shaded environments where many native species are already stressed by other invasive plants. Because it is naturalized and possesses traits that are cause for concern, it could detrimentally impact tropical island ecosystems if its spread continues unchecked. Although already widespread in parts of Hawaiʻi, it is still important to discourage new plantings, manage existing populations where feasible, and prevent expansion into less-invaded areas. When possible, choose low-risk or native alternatives better suited to restoration and landscaping in Hawaiʻi.

High Risk Traits:

• Elevation range exceeds 1000 m, demonstrating environmental versatility
  
• Thrives in tropical climates
  
• Naturalized in the Hawaiian Islands and elsewhere
  
• A disturbance-adapted grass
  
• A weed of several agricultural crops of the tropics
  
• An environmental weed
  
• Other Setaria species have become invasive
  
• Host of plant pests and pathogens
  
• Covered with irritating hairs
  
• Shade-tolerant
  
• Tolerates many soil types
  
• Forms dense ground cover and excludes other vegetation
  
• Reproduces by seed
  
• Seeds dispersed by gravity, water, as a contaminant, animals and intentionally by people
  
• Tolerates fire and able to resprout after cutting
  
• No effective biocontrol agents known

Low Risk Traits:

• Palatable to animals and edible to people
  
• Limited vegetative spread
  
• Herbicides may provide effective control