Family: Asteraceae

Origin, Description & Uses:
Roldana petasitis, commonly known as velvet groundsel, is a fast-growing shrub native to eastern Mexico. It is valued as an ornamental plant for its large, soft, velvety leaves and clusters of bright yellow daisy-like flowers that bloom throughout much of the year. This species thrives in warm, moist environments and is often planted in tropical and subtropical gardens as a foliage accent or screening plant. Its lush appearance and ability to grow quickly have made it popular in landscaping, particularly in humid climates.

Risks & Threats:
In Hawai‘i, velvet groundsel is naturalized and poses a high risk to tropical island ecosystems. This species spreads readily by seed and vegetative growth, allowing it to establish dense stands that can outcompete native vegetation and alter natural habitats. Its vigorous growth, tolerance of disturbed areas, and ability to thrive in wet tropical conditions are traits that raise concern for forest edges, roadsides, and unmanaged landscapes. Because it possesses invasive characteristics that could detrimentally impact Hawai‘i’s ecosystems, planting velvet groundsel is discouraged. When possible, choose low risk or native alternatives for landscaping and restoration projects. In areas where this species is already widespread, landowners and gardeners are encouraged to manage existing plants carefully and prevent further spread into natural or less-invaded areas.

High Risk Traits:

• Naturalized in New Zealand & Australia
  
• Environmental weed in multiple regions
  
• Banned from sale/propagation in some areas
  
• Toxic to animals (rabbits) and humans
  
• Causes skin allergies
  
• Shade tolerant
  
• Tolerates wide range of soils
  
• Produces viable, wind-dispersed seeds
  
• Reproduces vegetatively (stem fragments, layering)
  
• Spreads via dumped garden waste
  
• Resprouts after fire & cutting
  
• Forms dense stands, crowds out natives
  
• Host for pest nematode

Low Risk Traits:

• No spines, thorns, or burrs
  
• No specialist pollinators needed
  
• No fire hazard
  
• Not dispersed by water, birds, or external animal attachment
  
• Controlled by herbicides
  
• No persistent seed bank confirmed