Family: Iridaceae

Origin, Description & Uses
Gladiolus dalenii, commonly known as dragon’s head lily, parrot lily, or sword lily, is a striking flowering plant native to sub-Saharan Africa. It is recognized for its tall, sword-like leaves and vibrant, showy flowers that come in a range of colors including red, orange, yellow, and pink. Often grown for ornamental purposes, this lily is popular in gardens and floral arrangements due to its dramatic blooms and long-lasting flowers. It thrives in well-drained soils and sunny locations, making it a favored choice for tropical and subtropical landscapes.

Risks & Threats
This species is now naturalized across Kaua’i, O’ahu, Maui, and Hawai’i, and it possesses traits that raise ecological concerns. Gladiolus dalenii can spread aggressively in suitable habitats, potentially outcompeting native plants and altering native plant communities. Its ability to establish quickly and produce large numbers of corms allows it to persist and expand in wild areas. Because of these characteristics, it could negatively impact Hawaii’s fragile tropical island ecosystems. For gardeners and landscapers, it is recommended to choose a low-risk or native alternative that provides beauty without the ecological risks.

High Risk Traits:

• Broad climate suitability and elevation range
  
• Able to grow in tropical climates
  
• Naturalized on Kaua'i, O'ahu, Maui, and Hawai'i (Hawaiian Islands), as well as Alabama, Louisiana, and Australia
  
• Other Gladiolus species are invasive weeds
  
• Geophyte
  
• Reproduces by seeds, corms and possibly bulbils
  
• Spread by wind-dispersed seeds and discarded bulbs, as well as by intentional planting
  
• Seeds able to be stored for extended periods; May form a persistent seed bank
  
• Limited biological and ecological information may reduce accuracy of risk prediction

Low Risk Traits:

• Despite naturalization, no documented reports of negative impacts to date
  
• Unarmed (no spines, thorns, or burrs)
  
• Corms palatable to animals (may be consumed by pigs)
  
• Ornamental
  
• Prefers full sun (may limit ability to spread into shaded habitats)
  
• Herbicides may provide effective control