Family: Asteraceae

Origin, Description & Uses
Pluchea indica (Indian fleabane) is native to tropical and subtropical regions of Asia extending to northern Australia. It is a salt-tolerant shrub commonly found in coastal and wetland habitats, especially in saline or brackish environments such as mangroves, estuaries, and tidal flats. The plant typically grows as a dense, multi-branched shrub with aromatic leaves and clusters of small pink to purple flower heads. In its native range and elsewhere, it has been used in traditional medicine and occasionally as a folk remedy, and it may also provide some local value for soil stabilization in coastal areas due to its tolerance of harsh, saline conditions.

Risks & Threats
In Hawaiʻi, Pluchea indica is naturalized in low-elevation, dry to coastal habitats across Midway Atoll, Laysan, and all of the main islands. This species possesses traits that are cause for concern, including strong adaptability to disturbed coastal environments, tolerance of salt and drought, and the ability to form dense stands that can displace native vegetation. These characteristics allow it to spread in sensitive tropical island ecosystems where native coastal plants are already under pressure. Its expansion may reduce habitat quality for native species and alter coastal plant communities.

High Risk Traits:

• Naturalized outside native range (e.g., Hawaii)
  
• Agricultural/forestry/horticultural weed
  
• Environmental weed (displaces forage and native species, destroys waterbird habitat)
  
• Congeneric weed (e.g., P. lanceolata)
  
• Forms dense thickets
  
• Produces viable seed
  
• Hybridizes naturally
  
• Wind-dispersed propagules
  
• Tolerates mutilation, cultivation, or fire (proliferates after fire)

Low Risk Traits:

• No spines, thorns, or burrs
  
• No evidence of toxicity to animals or humans
  
• Not shade tolerant (based on scoring)
  
• Tolerates narrow soil conditions (saline/coastal only)
  
• Controlled by herbicides (glyphosate, 2,4-D)