Family: Asteraceae

Arctotheca calendula (capeweed) is a low-growing perennial herb native to South Africa that has spread widely in temperate regions around the world, including Australia, New Zealand, and California. It forms dense, sprawling mats that can crowd out native plants and desirable pasture species, especially in disturbed or open areas. The plant is easily recognized by its rosette of silvery-green, lobed leaves and bright yellow, daisy-like flowers. Capeweed reproduces readily by seed, which can be dispersed by wind, water, animals, and vehicles.

Although Arctotheca calendula is not known to be naturalized in Hawaiʻi, a related species (Arctotheca prostrata) is naturalized on Maui. A. calendula possesses traits that could allow it to establish and spread in the islands, including rapid growth, prolific seed production, and tolerance of poor soils. Because of its invasive behavior elsewhere and potential ecological impacts, capeweed is considered a high-risk species and is not recommended for cultivation in Hawaiʻi.

High Risk Traits:

• Invasive globally (agricultural & environmental weed)
  
• Toxic to livestock
  
• High seed production & persistent seed bank
  
• Spreads by seeds, stolons, and tubers
  
• Multiple dispersal: wind, animals, equipment
  
• Herbicide-resistant biotypes
  
• Tolerates soil disturbance

Low Risk Traits:

• Not shade tolerant
  
• Not spiny or parasitic
  
• Not toxic to humans
  
• Not in horticultural trade
  
• Not present in Hawaii