Family: Rosaceae

Origin, Description & Uses
Pyrus calleryana (Bradford pear, Callery pear) is native to central and southern China, Vietnam, Taiwan, and parts of Japan. It is a fast-growing deciduous tree widely planted as an ornamental for its showy white spring blossoms, glossy green leaves, and vibrant red to purple fall color. Many cultivated forms, including the well-known ‘Bradford’ pear, were developed for uniform shape and tolerance to urban conditions. It has commonly been used in landscaping, along streets, and in residential plantings due to its adaptability, rapid growth, and ability to grow in a wide range of soils and environments.

Risks & Threats
Although Pyrus calleryana is currently not known to be naturalized in the Hawaiian Islands, it does possess traits that are cause for concern and could detrimentally impact tropical island ecosystems if it becomes established. In other regions, it has shown strong invasive tendencies, spreading through bird-dispersed seeds and forming dense thickets that displace native vegetation. Ornamental varieties can also cross-pollinate, producing vigorous offspring with thorny branches and poor structural integrity, increasing spread into natural areas and creating hazards in managed landscapes. Its tendency to break easily in storms and its short lifespan can also lead to increased disturbance and regeneration from seed. Because of these risks, choosing a low-risk or native alternative is recommended whenever suitable options are available to support resilient, biodiverse Hawaiian ecosystems.

High Risk Traits:

• Broad climate suitability
  
• Naturalized across North America
  
• Can grow in subtropical climates
  
• Invades disturbed areas
  
• Thorny
  
• Potentially allelopathic
  
• Seeds contain a small amount of cyanide – risk of accidental poisoning
  
• Tolerates many soil conditions (and potentially able to exploit many different habitat types)
  
• Can form dense, thorny thickets
  
• Hybridizes with other cultivars and species and increases invasiveness
  
• Can spread vegetatively by root suckering
  
• Fleshy-fruited; Seeds dispersed by birds and mammals
  
• Seeds persist in the soil; forms a seed bank
  
• Tolerates cutting and fires

Low Risk Traits:

• Foliage palatable to deer and other browsing animals
  
• Relatively Shade-intolerant
  
• Self-incompatible
  
• Landscaping and ornamental value
  
• Herbicides may provide effective control