Family: Poaceae

Considered very invasive and dangerous to Hawaiʻi’s health, economy and way of life; C. jubata is on the Hawaiʻi State Noxious Weed List. The Division of Forestry and Wildlife of the Hawaiʻi Department of Land and Natural Resources has designated this species as one of Hawaiʻi’s Most Invasive Horticultural Plants.

Plants are being controlled, with the permission of landowners, on Oahu, Maui, and Hawaii Island.

Description and Dispersal:

• Large clumping grass that may reach 6 ft or taller
  
• Leaves are narrow and have sharp, serrated edges
  
• Showy white to purple flower plumes (24 - 31 in) tower three times higher than the foliage
  
• C. jubata plants have both female and male flowers and are able to produce viable seeds without cross-pollination
  
• C. selloana plants have either male or female flowers and require cross-pollination between male and female plants to produce viable seeds

High Risk Traits:

• Naturalized and invasive in multiple regions
  
• Broad environmental tolerance (soil, moisture, light)
  
• High seed production (>100,000 per inflorescence)
  
• Multiple dispersal vectors (wind, water, human, animal)
  
• Forms dense, monotypic stands
  
• Increases fire hazard
  
• Sharp leaves cause injury
  
• Listed as a noxious weed in many areas
  
• Can flower in 1–2 years
  
• Resprouts after fire or cutting

Low Risk Traits:

• Not allelopathic or parasitic
  
• Not toxic to animals or humans
  
• Palatable to livestock
  
• No persistent seed bank (>6 months)
  
• Can be controlled with herbicides