Family: Apocynaceae

Origin, Description & Uses:
Vinca major, commonly known as bigleaf periwinkle, is a trailing, evergreen perennial native to the Mediterranean region of southern Europe and western Asia. It forms dense mats of glossy green leaves and produces attractive blue to violet, five-petaled flowers over a long blooming season. Because of its vigorous growth, tolerance of shade, and ability to stabilize soil, it has been widely planted as an ornamental groundcover in gardens, landscapes, and on slopes for erosion control.

Risks & Threats:
In Hawaiʻi, Vinca major is naturalized on Maui and Hawaiʻi Island. It possesses traits that are cause for concern, including rapid vegetative spread through creeping stems that readily root at the nodes, allowing it to form dense carpets that outcompete native vegetation and suppress the regeneration of other plants. It can invade forests, riparian areas, roadsides, and other disturbed habitats, where it may detrimentally impact tropical island ecosystems by reducing native plant diversity and altering habitat structure. Because this species is already naturalized in Hawaiʻi, further planting and intentional spread should be avoided, particularly near natural areas or on islands where it is not yet widespread. Where suitable, choose a low-risk or native groundcover alternative instead. In areas where Vinca major is already established, manage existing plantings and prevent its escape into surrounding natural habitats to help minimize further environmental impacts.

High Risk Traits:

• Broad climate suitability
  
• Naturalized in areas with tropical climates
  
• Widely naturalized, including Maui, Hawaiian Islands
  
• Yard weed and environmental weed, reducing native plant biodiversity
  
• Vinca minor is also invasive
  
• Relatively unpalatable to browsing and grazing animals
  
• Toxic to animals and potentially toxic, and allergenic to humans
  
• Alternate host of the bacteria causing Pierce's disease, a threat to California's vineyards
  
• Shade-tolerant
  
• Tolerates many soil types
  
• Forms thick mats that smother the ground and low-growing vegetation
  
• Reproduces rapidly by vegetative means
  
• Vegetative fragments spread in garden waste, and by water
  
• Able to resprout after cutting, or fires

Low Risk Traits:

• Unarmed (no spines, thorns or burrs)
  
• Ornamental and medicinal uses
  
• Rarely, if ever, produces seeds in introduced range
  
• Lack of seed production may limit ability to disperse and spread
  
• Certain herbicides may provide effective control