Family: Typhaceae

Origin, Description & Uses
Typha latifolia (common cattail, broadleaf cattail) is a tall, perennial wetland plant with broad, flat leaves and distinctive brown, cigar-shaped flower spikes. It has an exceptionally broad native range spanning much of the temperate Northern Hemisphere, extending into parts of Central and South America, Africa, and South Asia. Common cattail grows in marshes, ponds, stream margins, irrigation ditches, and other shallow freshwater habitats. It has long been valued for wetland restoration, erosion control, wastewater treatment, wildlife habitat, and traditional uses, with its young shoots, pollen, and rhizomes being edible and its leaves and stems used for weaving mats, baskets, and other crafts.

Risks & Threats
In Hawaiʻi, Typha latifolia is naturalized on Kauaʻi, Oʻahu, and Hawaiʻi Island. Although widely recognized as a beneficial wetland plant in some settings, it possesses traits that are cause for concern in tropical island ecosystems. It spreads aggressively by both abundant wind-dispersed seeds and extensive underground rhizomes, allowing it to rapidly form dense, nearly impenetrable stands that displace native wetland vegetation, alter hydrology, reduce open-water habitat, and change nutrient cycling. Dense cattail infestations can also increase sediment accumulation and create conditions that favor further invasion. Because this species is already established in parts of Hawaiʻi, planting it can contribute to its continued spread into uninfested wetlands. Where possible, choose a low-risk or native alternative for landscaping or restoration projects. In areas where common cattail is already widespread, avoid planting it near natural wetlands and manage existing populations to help prevent further expansion into sensitive habitats.

High Risk Traits:

• Broad climate suitability and environmental versatility
  
• Grows from temperate to tropical climates
  
• Naturalized on Kauai, Oahu, and Hawaii (Hawaiian Islands) and elsewhere
  
• A disturbance weed that impacts agriculture and aquatic resources
  
• Potential environmental weed
  
• Other Typha species are invasive
  
• Reports of potential toxicity to animals and humans (conflicting accounts)
  
• Tolerates many soil types
  
• Capable of forming dense monocultures in aquatic habitats
  
• Reproduces by seeds and vegetatively by rhizomes
  
• Hybridizes with other Typha species
  
• Self-fertile
  
• Reaches maturity in 2 years (from seed)
  
• Seeds dispersed by wind, water, soil movement and external attachment to animals and equipment
  
• Intentionally planted by people
  
• Seeds survive gut passage (ducks)
  
• Prolific seed production
  
• Forms a persistent seed bank
  
• Able to resprout after fire

Low Risk Traits:

• Unarmed (no spines, thorns, or burrs)
  
• Palatable to animals and provides shelter for water birds
  
• Ornamental
  
• Herbicides provide effective control