Family: Poaceae

Origin, Description & Uses
Polypogon monspeliensis (rabbitfoot grass) is native to a broad region spanning Macaronesia, western and southern Europe, temperate eastern Asia, and parts of North Africa extending to Tanzania. It is an annual grass commonly found in moist, disturbed environments such as wetlands, stream edges, ditches, agricultural fields, and roadsides. The plant is easily recognized by its soft, feathery, foxtail-like flower heads that resemble a rabbit’s foot, which give the species its common name. While it has limited intentional uses, it has occasionally been introduced as a forage grass or for soil stabilization, though it is more often encountered as a weedy species.

Risks & Threats
Rabbitfoot grass is naturalized across Hawaiʻi, including Kuaihelani (Midway Atoll), Kauaʻi, Oʻahu, Maui, and Hawaiʻi Island. It possesses traits that are cause for concern, including high seed production, efficient dispersal by wind and water, and a strong ability to colonize disturbed, wet habitats. These characteristics allow it to spread rapidly and compete with native wetland and riparian plants, potentially altering habitat structure and reducing biodiversity in sensitive tropical island ecosystems. As a result, this species could detrimentally impact Hawaiian ecosystems where it becomes established. Choosing low-risk or native alternatives is recommended whenever available. Where rabbitfoot grass is already widespread, management should focus on preventing further spread into less-impacted areas to minimize additional ecological harm.

High Risk Traits:

• Broad climate suitability (temperate & tropical)
  
• Naturalized beyond native range (widespread)
  
• Environmental weed (forms dense swards, outcompetes natives)
  
• Congeneric weeds exist
  
• Allelopathic (affects following season's crops)
  
• Forms dense thickets
  
• Produces viable seed annually
  
• Hybridizes naturally (including intergeneric)
  
• Wind-dispersed propagules
  
• Water-dispersed propagules
  
• Dispersed externally by animals
  
• Prolific seed production (>1000/plant)
  
• Persistent seed bank (1–5 years)

Low Risk Traits:

• No spines, thorns, or burrs
  
• Palatable to grazing animals (used as forage)
  
• No fire hazard (wetland habitats)
  
• Not shade tolerant
  
• Narrow soil requirements (fertile, moist to wet)
  
• No vegetative fragmentation (doubtful reproduction)
  
• Not bird-dispersed (seeds eaten, not dispersed)
  
• Controlled by herbicides
  
• Does not resprout after above-ground removal