Family: Liliaceae

Lilium formosanum, commonly known as the Formosa lily or Taiwan lily, is a perennial flowering plant native to Taiwan. It belongs to the Liliaceae family and is admired for its tall, slender stems and large, fragrant, trumpet-shaped white flowers, often tinged with purple on the outside.

While prized as an ornamental plant, Lilium formosanum is considered invasive in some regions, particularly in parts of Australia (especially Lord Howe Island and Norfolk Island) and New Zealand. Its ability to grow in a wide range of conditions, combined with prolific seed production, wind-dispersed seeds, and bulbs that help it to persist in unfavorable conditions, allow it to outcompete native flora. In these areas, it has naturalized in disturbed habitats, roadsides, and open grasslands, threatening native biodiversity. Efforts to manage its spread often involve manual removal and the discouragement of its cultivation in areas prone to invasion. To date, it is reported to be cultivated, but not naturalized, or invasive, in the Hawaiian Islands.

High Risk Traits:

• Grows and can spread in regions with tropical climates
  
• Broad climate suitability and elevation range
  
• Naturalized in New Zealand, Norfolk Island, Australia, South America, Japan, and South Africa
  
• A disturbance adapted weed that can potentially invade agricultural sites or natural areas
  
• An environmental weed in Australia, threatening native biodiversity on Lord Howe Island and Norfolk Island
  
• Other Lilium species are invasive
  
• Reported to be toxic to animals and humans
  
• Tolerates many soil types (not limited by substrate)
  
• Reported to form dense stands that can exclude other vegetation
  
• A geophyte, with bulbs able to persist in the soil from season to season
  
• Reproduces by seed
  
• Self-fertile
  
• Able to spread vegetatively from dispersal or fragmentation of bulbs
  
• Reaches maturity in 9-12 months from seeds
  
• Seeds, bulbs and bulb scales spread by water, wind, humans, contaminated soil (earthmoving equipment, car tires etc) and garden refuse dumping.
  
• Capable of prolific seed production
  
• Tolerates mechanical damage and fire

Low Risk Traits:

• Unarmed (no spines, thorns, or burrs)
  
• Grows best in high light environments (dense shade may inhibit spread)
  
• Herbicides may provide effective control