Family: Oxalidaceae

Origin, Description & Uses
Oxalis debilis (large-flowered pink sorrel, pink shamrock) is native to Central America and parts of northern South America, including regions from Guyana to Paraguay. It is a low-growing, herbaceous plant known for its clover-like, trifoliate leaves and delicate pink flowers. The plant spreads from small underground bulbils and forms dense ground cover in suitable conditions. It is sometimes grown as an ornamental for its attractive foliage and flowers, and it can also be found in gardens and disturbed sites where it establishes easily.

Risks & Threats
This species is naturalized across the Hawaiian Islands, including Kauaʻi, Oʻahu, Molokaʻi, Lānaʻi, Maui, Hawaiʻi Island, and Midway Atoll. Oxalis debilis has traits that make it highly persistent and difficult to control, including rapid vegetative reproduction and the ability to spread from tiny bulbils that are easily moved in soil and garden materials. It can form dense mats that compete with native vegetation and alter ground cover dynamics. Because of its invasiveness and adaptability, this species is considered a cause for concern and could detrimentally impact tropical island ecosystems by displacing native plants and spreading further into natural and managed habitats.

High Risk Traits:

• Grows in warm temperate to tropical climates
  
• Naturalized on all the main Hawaiian Islands except Ni'ihau and Kaho'olawe; widely naturalized elsewhere
  
• Garden and disturbance adapted weed
  
• Potential crop and environmental weed (impacts generally innocuous)
  
• Other Oxalis species are invasive
  
• Potentially allelopathic
  
• May be toxic to animals and people if consumed in large quantities due to high levels of oxalate
  
• Shade tolerant
  
• Persists from bulbs and spreads vegetatively from bulbils
  
• Bulbils spread in soil, as a pot contaminant, and potentially by people

Low Risk Traits:

• Despite widespread naturalization and weediness, generally not regarded as a significant problem in agricultural or natural areas
  
• Unarmed (no spines, thorns, or burrs)
  
• Provides fodder for livestock (palatable despite potential toxicity)
  
• Limited or no seed production in Hawaiian Islands, and other locations outside native range
  
• Herbicides may provide effective control