Family: Geraniaceae

Origin, Description & Uses
Geranium homeanum, commonly known as Australasian cranesbill or Australasian geranium, is native to parts of Australia and New Zealand. It is a perennial herbaceous plant characterized by its soft, deeply lobed green leaves and small, delicate flowers that range from pale pink to purple with darker veining. This species typically grows in moist, shaded environments such as forest understories, streambanks, and disturbed sites. While not widely cultivated for commercial purposes, it may be used ornamentally in gardens for its attractive foliage and subtle blooms, and it can serve as a groundcover in suitable climates.

Risks & Threats
In the Hawaiian Islands, Geranium homeanum is naturalized on Kauaʻi, Maui, and Hawaiʻi. It possesses traits that are cause for concern, including its ability to thrive in shaded, moist habitats and to spread in disturbed and natural ecosystems. This species can form dense patches that compete with native understory plants for space, light, and nutrients, potentially reducing biodiversity. Its adaptability and tolerance of a range of environmental conditions increase the risk of further spread. As a result, it could detrimentally impact tropical island ecosystems by altering native plant communities and ecosystem dynamics if left unmanaged.

High Risk Traits:

• Elevation range exceeds 1000 m, demonstrating environmental versatility
  
• Able to grow in tropical climates
  
• Naturalized on Kauai, Maui, and Hawaii, Hawaiian Islands
  
• Other Geranium species have become invasive
  
• Shade-tolerant
  
• Reproduces by seeds
  
• Hybridizes with other Geranium species
  
• Perennial, but able to reproduce in one growing season
  
• Small seeds, possibly spread through ballistic dispersal or by other means
  
• Seeds possess physical dormancy and can form a persistent seed bank
  
• Able to resprout after fire

Low Risk Traits:

• Weedy, but impacts generally not specified in introduced range
  
• Unarmed (no spines, thorns or burrs)
  
• Not reported to spread vegetatively
  
• Limited ecological information makes accurate risk prediction difficult