Family: Magnoliaceae

Origin, Description & Uses:
Liriodendron tulipifera, commonly known as tulip poplar or yellow poplar, is a large deciduous tree native to eastern North America, ranging from southern Ontario through the central and eastern United States. Despite its common name, it is not a true poplar, but a member of the magnolia family. The tree is well known for its tall, straight trunk, distinctive four-lobed leaves, and large tulip-shaped greenish-yellow flowers with orange markings. Tulip poplar is widely planted as an ornamental and shade tree because of its rapid growth, attractive form, and colorful fall foliage. Its lightweight, workable wood has also been valued for lumber, veneer, furniture, and carving.

Risks & Threats:
Tulip poplar is naturalized in Hawaiʻi and possesses traits that are cause for concern in tropical island ecosystems. The species grows quickly, produces abundant wind-dispersed seeds, and can establish in disturbed habitats where it may compete with other vegetation. Although it is not currently considered among Hawaiʻi’s most aggressive invasive trees, its ability to spread beyond cultivation suggests that caution is warranted. Large trees may also alter light levels, soil conditions, and habitat structure in areas where they become established. Careful monitoring and responsible planting practices are recommended to help ensure that Liriodendron tulipifera does not negatively impact Hawaiʻi’s native ecosystems or surrounding landscapes.

High Risk Traits:

• Broad climate suitability (environmentally versatile)
  
• History of repeated introductions outside native range
  
• Naturalized in some regions (e.g., Hawai'i, Portugal)
  
• Functions as a weed in disturbed areas & garden/amenity settings
  
• Forms dense, even-aged stands (can develop pure thickets)
  
• Tolerates wide range of soil conditions
  
• Produces viable seed
  
• Self-compatible (self-pollination possible)
  
• Seeds adapted for wind dispersal (to 4-5x tree height)
  
• Seeds intentionally dispersed by people (ornamental, timber)
  
• Persistent seed bank (viable 4-7 years)
  
• Tolerates mutilation, coppicing, and fire (resprouts)

Low Risk Traits:

• Not native in tropical/subtropical climates (requires cold stratification)
  
• No evidence of environmental weed status
  
• No spines, thorns, or burrs
  
• Not allelopathic
  
• Palatable to grazing animals (browsed by deer & livestock)
  
• No evidence of toxicity to animals or humans
  
• Not shade tolerant (requires high light)
  
• Low seed production per area (<370 seeds/m²)