Family: Rubiaceae

Origin, Description & Uses:
Serissa (Serissa japonica) is a small evergreen shrub native to southern China and Taiwan. It is prized as an ornamental plant for its compact growth habit, fine-textured foliage, and abundant display of small white flowers that bloom over a long season. Some cultivars also feature variegated leaves or pink-tinged blossoms. Because it responds well to pruning and shaping, serissa is widely used in bonsai culture, foundation plantings, borders, hedges, and container gardens. Its attractive appearance and manageable size have made it a popular landscape and nursery plant in tropical and subtropical regions, including Hawaiʻi.

Risks & Threats:
Serissa is naturalized in Hawaiʻi, meaning it has established self-sustaining populations outside cultivation. However, it is considered a low-risk species and has not demonstrated the aggressive invasive behavior seen in many problematic ornamental plants. While it can occasionally spread from planted areas, there is little evidence that it forms dense infestations or significantly impacts native ecosystems. As with any naturalized species, gardeners should monitor for unwanted spread and dispose of plant material responsibly. Current evidence suggests that serissa poses minimal ecological risk in Hawaiʻi and can be grown with relatively low concern for environmental impacts.

High Risk Traits:

• Repeated introductions worldwide as ornamental/bonsai
  
• Naturalized on Hawai'i Island
  
• Host for multiple quarantine pests and pathogens
  
• Tolerates wide range of soil types
  
• Responds well to pruning (tolerates mutilation)

Low Risk Traits:

• Not a weed (garden, agricultural, or environmental)
  
• No spines, toxins, or allelopathy
  
• No vegetative spread in the wild
  
• No prolific seed production or persistent seed bank