Family: Proteaceae

Origin, Description & Uses:
Grevillea banksii, commonly known as red silk oak, is a tree native to Australia. It is admired for its striking, bright red, spider-like flowers and attractive fern-like foliage. This fast-growing tree can reach heights of 10–15 meters and is often used in landscaping for ornamental purposes, windbreaks, and erosion control. Its vibrant flowers also attract birds and pollinators, making it a popular choice in gardens and urban plantings.

Risks & Threats:
In the Hawaiian Islands, Grevillea banksii is naturalized on Ni‘ihau, Kaua‘i, O‘ahu, Moloka‘i, Maui, and Hawai‘i. It possesses traits that are cause for concern, including rapid growth, high seed production, and the ability to outcompete native plants. This species can spread into natural areas, displacing native vegetation, altering habitats, and potentially impacting the ecological balance of tropical island ecosystems. Land managers and gardeners should exercise caution to prevent further spread.

High Risk Traits:

• Naturalized beyond native range (e.g., Hawaii, South Africa's Natal region)
  
• Agricultural/forestry/horticultural weed (infests pastures; listed on Hawaii state noxious weed list)
  
• Toxic to animals (foliage poisonous to horses)
  
• Causes allergies or is otherwise toxic to humans (dermatitis, hay fever, skin irritation)
  
• Produces viable seed
  
• Hybridizes naturally
  
• Self-compatible or apomictic (often self-seeds)
  
• Propagules dispersed intentionally by people (ornamental value)
  
• Propagules adapted to wind dispersal
  
• Evidence of a persistent propagule bank (seeds dormant for >1 year)

Low Risk Traits:

• Produces no spines, thorns, or burrs
  
• Not shade tolerant (requires full sun)
  
• Does not tolerate a wide range of soil conditions (sensitive to high phosphorus)
  
• No evidence of vegetative reproduction (fragmentation) in the wild
  
• Propagules not likely to be dispersed unintentionally (no attachment structures)
  
• Propagules not dispersed by water, birds, or other animals (externally)
  
• No evidence propagules survive passage through the gut