Family: Asteraceae

Cichorium intybus (chicory, Belgium endive, coffee chicory, French endive, succory, witloof) is a hardy perennial herb in the daisy family, native to Europe and parts of western Asia and Africa. It is easily recognized by its bright blue flowers, coarse leaves, and deep taproot. Chicory has a long history of human use: selected varieties are grown as leafy vegetables or blanched endives, while the roots are roasted and used as a caffeine-free coffee substitute. The plant is also valued as livestock forage and has been used traditionally for medicinal purposes.

In Hawaiʻi, chicory poses environmental and agricultural concerns. It is tolerant of a wide range of conditions, produces abundant seed, and can regrow from root fragments, allowing it to persist and spread once established. The species is widely naturalized elsewhere and can behave as a disturbance weed, competing with desirable plants and contaminating agricultural fields. Although some cultivated forms are managed, unmanaged populations may spread into open or disturbed areas, making chicory a species of concern for Hawaiʻi landscapes.

High Risk Traits:

• Broad climate suitability
  
• Primarily a temperate species, but able to grow in regions with tropical climates
  
• Widely naturalized outside native range, but no evidence in Hawaiian Islands to date
  
• A disturbance weed with negative impacts on agriculture
  
• A potential environmental weed (reports from Australia are mostly anecdotal)
  
• Other Cichorium species are invasive
  
• Possibly toxic to pigs
  
• May cause contact dermatitis
  
• Tolerates many soil types (substrate not a limiting factor to spread)
  
• Reproduces by seeds and vegetatively from root fragments
  
• Hybridizes with other Cichorium species
  
• Some populations are self-compatible (although self-incompatibility is generally reported)
  
• A biennial that sometimes reaches maturity in first growing season
  
• Seeds dispersed intentionally and unintentionally by people, animals, wind (short distances) and water
  
• Can become a seed contaminant of other crops
  
• Prolific seed production
  
• Some viable seeds persist in the soil for several years
  
• Resprouts from roots after cutting, mowing or grazing

Low Risk Traits:

• Domesticated, self-incompatible forms exist that may reduce risk of escape and spread
  
• Unarmed (no spines, thorns, or burrs)
  
• Thrives in full sun (tolerates partial shade), which may limit spread into intact forests
  
• Provides fodder for livestock (palatable despite reports of toxicity to pigs)
  
• Economic value as a crop may outweigh negatives in certain situations
  
• Some herbicides provide effective control