Family: Cleomaceae

Cleome houtteana (spider flower, spider plant, pink queen) is an herbaceous plant usually cultivated as an annual, native to Argentina, Brazil, and Paraguay. It is cultivated ornamentally for its showy blooms. It is naturalized in China and North America and reported to be potentially naturalizing on O’ahu. Its further spread seems likely due to its rapid maturation and ability to self-seed.

High Risk Traits:

• Broad climate suitability (native to tropical climates and widely naturalized in warm temperate to tropical regions)
  
• Widely naturalized in North America, China, and elsewhere (but no evidence in the Hawaiian Islands to date)
  
• A weedy plant of disturbed habitats, and anecdotally reported to be a problem in gardens and landscape settings
  
• Other Cleome species are invasive weeds
  
• Leaves with stipular and scattered spines
  
• Unpalatable to deer, rabbits, and cattle
  
• Tolerates many soil types
  
• Reproduces by seeds
  
• Self-fertile
  
• Annual life cycle, reaching maturity in one growing season
  
• Seeds dispersed through dehiscence, and possibly as a soil contaminant, by water, and through intentional cultivation

Low Risk Traits:

• Despite widespread naturalization, negative impacts appear to be minor and largely restricted to disturbed environments
  
• Non-toxic
  
• Grows best in high light environments (dense shade may inhibit spread)
  
• Herbicides may provide effective control