Family: Poaceae

Origin, Description & Uses
Cymbopogon nardus (Citronella) is a perennial grass native to South and Southeast Asia, including India, Sri Lanka, and Indonesia. It grows in dense clumps up to 1.5 meters tall and has long, narrow, aromatic leaves. Citronella is best known for its essential oil, which is extracted from the leaves and used in insect repellents, perfumes, and aromatherapy products. It is also cultivated as an ornamental plant in gardens and landscaping for its tall, graceful foliage and its pleasant, lemony fragrance.

Risks & Threats
Although Cymbopogon nardus is not currently known to be naturalized in Hawaii, it possesses traits that could make it a concern for tropical island ecosystems, such as rapid vegetative growth and the ability to form dense stands that could outcompete native plants. It is not considered invasive yet, but careful management is recommended. For gardeners seeking similar benefits, it is wise to choose a low-risk or native alternative to avoid potential ecological impacts.

High Risk Traits:

• Thrives in tropical climates
  
• Naturalized in Taiwan, the Bahamas and possibly elsewhere
  
• Pasture weed that replaces desirable forage species
  
• Unpalatable to cattle
  
• Tolerates many soil types
  
• Seeds are wind-dispersed
  
• Tolerates fire and benefits from frequent fire regime

Low Risk Traits:

• Unarmed (no spines, thorns or burrs)
  
• Source of essential oils
  
• Does not spread by runners
  
• May have limited seed set within introduced range