Family: Sapindaceae

Origin, Description & Uses
Dimocarpus longan, commonly known as longan or dragon’s eye, is a tropical fruit tree native to southern China and parts of Southeast Asia. It is closely related to lychee and rambutan and is widely cultivated in warm regions around the world. The tree is medium-sized, with dense, glossy green foliage and spreading branches that provide ample shade. It produces clusters of small, round fruits with thin, tan-colored skin. When peeled, the translucent white flesh surrounds a single dark seed, giving rise to the name “dragon’s eye.” Longan fruit is sweet and aromatic and is enjoyed fresh, dried, or canned. It is also used in beverages, desserts, and traditional Asian dishes, and has a long history of use in traditional medicine.

Risks & Threats
Longan is considered a low-risk species for Hawai‘i. While it can produce viable seeds, it is typically cultivated in orchards or home gardens and does not commonly spread into natural areas. The tree generally requires warm temperatures and consistent care to thrive, limiting its ability to establish aggressively outside of managed landscapes. There is little evidence of longan forming dense stands or displacing native vegetation in the Hawaiian Islands. As with any non-native plant, responsible cultivation and proper disposal of yard waste are recommended, but overall, longan is regarded as a safe and productive choice for home gardens.

High Risk Traits:

• Naturalized: Established outside native range (e.g., New Guinea)
  
• Climate match: Highly suited to tropical/subtropical regions
  
• Repeated introductions: Widely introduced for cultivation
  
• Shade tolerant: Can establish in shaded understories
  
• Broad soil tolerance: Grows on various well-drained soils
  
• Self-compatible: Single plants can reproduce
  
• Seed dispersal: Viable seeds dispersed by birds and mammals (bats, civets)
  
• Pest host: Hosts fruit flies, webworms, scale insects, and diseases

Low Risk Traits:

• Domesticated: Long history of cultivation; wild origin uncertain
  
• Not a major weed: No evidence of significant agricultural or environmental impact
  
• No physical defenses: Lacks spines, thorns, or burrs
  
• Non-toxic: Not toxic to animals or humans
  
• No fire risk: Does not increase fire hazard
  
• No vegetative spread: Does not spread clonally
  
• Limited seed bank: Seeds lose viability quickly; no persistent seed bank
  
• Poor wind/water dispersal: Large seeds not adapted for wind or water dispersal