Family: Asteraceae

Origin, Description & Uses
Dimorphotheca ecklonis (Cape marguerite, also sold as Osteospermum cultivars such as ‘Asti White’ and Vanstaden’s river daisy) is native to the Cape Province region of South Africa, where it grows in coastal and subtropical habitats. It is a fast-growing perennial daisy known for its bright, showy white to purple ray flowers with contrasting centers and its ability to bloom for long periods. Because of its attractive appearance and tolerance of heat, wind, and dry conditions, it is widely cultivated worldwide as an ornamental plant in gardens, borders, and landscape plantings, especially in warm climates.

Risks & Threats
Although this species is currently not known to be naturalized in the Hawaiian Islands, it does possess traits that are cause for concern, and which could detrimentally impact tropical island ecosystems. It produces abundant seeds, establishes readily in disturbed sites, and is adapted to a wide range of environmental conditions, increasing its potential to escape cultivation and spread in suitable habitats. In climates similar to Hawaii, it may compete with native vegetation and alter habitat structure if it becomes established. Because of these risks, it is recommended to choose a low-risk or native alternative when available to reduce the chance of future ecological impacts.

High Risk Traits:

• Able to grow in 5 hardiness zones, demonstrating environmental versatility
  
• Able to grow in regions with subtropical climate
  
• Naturalized in Australia, Spain, California, and possibly elsewhere
  
• Regarded as an environmental weed in Australia
  
• Other Osteospermum species are weedy
  
• Toxic to livestock (contains hydrocyanic acid)
  
• Tolerates many soil types
  
• Reported to form dense stands in Australia
  
• Reproduces by seeds
  
• Able to reach maturity in <1 year
  
• Seeds dispersed by wind, water, dumped garden waste and intentionally by people
  
• Reported to resprout after cutting (if not uprooted)

Low Risk Traits:

• Unarmed (no spines, thorns, or burrs)
  
• Ornamental
  
• Thrives in high light environments (may not be able to invade forest understory)
  
• Not reported to spread vegetatively
  
• Herbicides may provide effective control