Family: Asteraceae

Origin, Description & Uses
Tragopogon porrifolius, commonly known as salsify, oyster plant, or purple salsify, is native to the Canary Islands, the Mediterranean region, and the Arabian Peninsula. It is a biennial herb with narrow, grass-like leaves and distinctive purple, dandelion-like flowers that open in the morning and close by midday. The plant produces long, edible taproots with a mild flavor often compared to oysters, along with edible young shoots and flower buds. Salsify has been cultivated for centuries as a root vegetable and is also grown as an ornamental for its attractive flowers and unusual seed heads.

Risks & Threats
Tragopogon porrifolius is naturalized in Hawaiʻi and possesses traits that are cause for concern in tropical island ecosystems. It reproduces readily by seed, and its lightweight, wind-dispersed seeds allow it to spread into disturbed areas, roadsides, grasslands, and open habitats where it can establish self-sustaining populations. Although it is primarily associated with disturbed environments, it has the potential to expand into suitable natural areas and compete with native vegetation. Because this species is already naturalized in Hawaiʻi, it is recommended that existing plants be managed responsibly and that new plantings be avoided, especially in areas where it is not yet widespread, to help minimize further spread. Whenever possible, choose low-risk or native alternatives for landscaping and gardening.

High Risk Traits:

• Elevation range exceeds 1000 m, demonstrating environmental versatility
  
• Thrives in tropical climates
  
• Possibly naturalizing on Oahu, Hawaiian Islands (confirmation needed)
  
• Latex highly caustic to the skin, possibly poisonous if ingested
  
• Tolerates many soil types
  
• Seeds dispersed by birds and intentionally by people
  
• Seeds able to be stored for extended periods; May form a persistent seed bank
  
• Able to coppice and resprout after cutting

Low Risk Traits:

• No reports of invasiveness or naturalization (with the possible exception of Oahu(), but no evidence of widespread introduction outside native range
  
• Unarmed (no spines, thorns or burrs)
  
• Provides fodder for livestock (palatable despite reports of toxicity)
  
• Ornamental
  
• Not reported to spread vegetatively
  
• Limited ecological information makes accurate risk prediction difficult