Family: Fabaceae

Origin, Description & Uses
Crimson clover (Trifolium incarnatum), also known as Italian clover or carnation clover, is native to Europe eastward to northwestern Iran. This cool-season annual is easily recognized by its dense, upright crimson flower spikes and soft, hairy leaves and stems. It has long been cultivated as a forage crop for livestock, a cover crop, and a green manure because it fixes nitrogen, improves soil structure, helps reduce erosion, and provides abundant nectar for bees and other pollinators. It is also occasionally grown as an ornamental wildflower. In Hawaiʻi, Trifolium incarnatum has become naturalized on Maui.

Risks & Threats
Although Trifolium incarnatum is naturalized in Hawaiʻi, it is considered a low-risk species and has not demonstrated significant invasive behavior. It typically persists in disturbed sites, agricultural fields, roadsides, and other open habitats, but it does not readily spread into intact native ecosystems or form dense, persistent infestations. As with any non-native plant, it should be managed responsibly to prevent unnecessary spread into sensitive areas. When selecting plants for landscaping, restoration, or agriculture near native habitats, choosing native or other low-risk species remains the best way to help protect Hawaiʻi’s unique ecosystems.

High Risk Traits:

• Broad climate suitability (but may be restricted to higher elevation of tropical and subtropical islands)
  
• Naturalized on Maui, Hawaiian Islands and widely naturalized elsewhere
  
• A disturbance and minor crop weed
  
• Other Trifolium species are invasive
  
• Not toxic, but may cause mechanical damage to horses
  
• Host of crop pathogens
  
• Tolerates many soil types
  
• Reproduces by seeds
  
• Self-compatible (but primarily outcrossing)
  
• Annual (reaches maturity in 1 growing season)
  
• Seeds dispersed by animals and intentionally by people
  
• Seeds able to be stored for extended periods; May form a persistent seed bank

Low Risk Traits:

• Despite reports of invasiveness and naturalization, impacts are unspecified; generally regarded as a desirable plant
  
• Unarmed (no spines, thorns, or burrs)
  
• Provides fodder for livestock
  
• Requires full sun
  
• Not reported to spread vegetatively
  
• Herbicides, mowing and tillage may provide effective control