Family: Elaeagnaceae

Origin, Description & Uses:
Hippophae rhamnoides, commonly known as sea buckthorn or sallowthorn, is native to a wide range of temperate regions across Europe and Asia. It is a hardy, deciduous shrub or small tree that typically grows 6–20 feet tall, with narrow silvery-green leaves and dense, thorny branches. In late summer to fall, it produces bright orange berries that are rich in vitamins, antioxidants, and oils. Sea buckthorn is widely cultivated for its nutritional and medicinal value, as well as for use in juices, supplements, cosmetics, and skincare products. It is also planted for erosion control, windbreaks, and land restoration due to its ability to tolerate poor soils and fix nitrogen.

Risks & Threats:
Although Hippophae rhamnoides is not currently known to be naturalized in the Hawaiian Islands, it possesses several traits that raise concern for tropical island ecosystems. Its ability to fix nitrogen can alter soil chemistry, potentially favoring invasive species over native plants adapted to low-nutrient conditions. The plant produces abundant fruit that may be spread by birds and other animals, increasing its potential to escape cultivation. Its dense, thorny growth can form impenetrable thickets, outcompeting native vegetation and reducing habitat quality. Because of these characteristics, this species could become invasive and negatively impact Hawaii’s unique ecosystems if introduced or widely planted. If considering cultivation, it is recommended to choose a low-risk or native alternative better suited to Hawaii’s environment.

High Risk Traits:

• Broad climate suitability in temperate regions
  
• Elevation range exceeds 1000 m, demonstrating environmental versatility
  
• Naturalized in Ireland, and possible elsewhere (broad native range)
  
• Regarded as an environmental weed in Ireland (threatens dune diversity)
  
• Thorny
  
• Tolerates many soil types
  
• Forms dense thickets
  
• Nitrogen fixing (alters soil nutrients)
  
• Reproduces by seeds and vegetatively by suckers
  
• Seeds dispersed by birds, other frugivorous animals, water and intentionally by people
  
• Seeds able to be stored for extended periods; may form a persistent seed bank
  
• Able to coppice and resprout after cutting

Low Risk Traits:

• Natural populations do not occur where mean temperature exceeds 25°C (may limit ability to spread in tropical islands to higher elevations)
  
• Provides fodder for livestock
  
• Ornamental, medicinal and medical uses
  
• Values for soil stabilization and soil improvement
  
• Dioecious