Family: Scrophulariaceae

Buddleja asiatica, commonly known as Asian butterfly bush, is a fast-growing shrub native to tropical and subtropical regions of Asia, including India, China, and Southeast Asia. It typically grows 6–15 feet tall, with long, arching branches and clusters of small, fragrant white flowers that attract butterflies and other pollinators. In ornamental landscapes, it has been planted for its sweet scent and ability to draw wildlife, as well as for use as a hedge or informal screen.

In Hawai‘i, Buddleja asiatica is considered highly invasive and poses serious ecological risks. It spreads aggressively along forest edges, disturbed areas, and roadsides, forming dense thickets that crowd out native vegetation. Once established, it can alter habitat structure and reduce biodiversity, especially in dry to mesic forest zones. The plant produces abundant seeds that spread easily by wind and animals, allowing it to invade quickly and repeatedly. Because of its rapid growth and ability to dominate natural areas, Asian butterfly bush is rated high risk and should not be planted in Hawai‘i.

High Risk Traits:

• High climate suitability for tropics/subtropics
  
• Already naturalized outside native range (e.g., Hawaii)
  
• Acts as a disturbance/garden weed
  
• Has invasive relatives (e.g., Buddleja davidii)
  
• Produces abundant, wind-dispersed seeds
  
• Can reproduce vegetatively (cuttings/fragments)
  
• Tolerates mutilation (e.g., pruning)
  
• Lacks effective natural enemies in new regions

Low Risk Traits:

• Not a major agricultural weed
  
• No spines, thorns, burrs, or toxins
  
• Palatable to livestock; non-toxic to humans
  
• Requires cross-pollination (dioecious)
  
• Not shade-tolerant
  
• Propagules not dispersed by animals
  
• Controllable with herbicides