Family: Bignoniaceae

A fast-growing tree, commonly called Nile tulip, spreads from initial plantings. In its native range of tropical Africa, Nile tulip is a popular tree used to cure tobacco. According to the Bishop Museum, Nile tulip has been cultivated in Hawaiʻi since at least 1958. Some experts suggested Nile tulip is rare in cultivation; it was found growing in multiple locations on Hawaiʻi Island. Each site harbored many juvenile and seedling trees that were spreading: the Hilo Arboretum, roadside forestry plantings, the University of Hawaiʻi parking lot, at a residence in Waimea, and a few properties in South Kona. The Big Island Invasive Species Committee is working to eradicate these incipient trees off the island. All landowners have been more than cooperative in our efforts. To date, Hawaiʻi Island is the only place in the state where naturalization has been documented. Parts of Europe and the Himalayas also have documented naturalization records.

*Nile tulip looks similar to African tulip; they are in the same family. Some key differences, when compared to African tulip,  Nile tulip has clasping leaf-like stipules, prominent orange-red stripes in the flower throat and glabrous leaves (not hairy).

Description and Dispersal:

• Evergreen tree with an irregular crown up to 45' tall
  
• Bark is reddish brown and finely cracked
  
• Yellow trumpet shaped flowers with orange reddish stripes in the throat
  
• Compound, pinnate leaves with 7-11 leaflets that can grow up to 4" and are wider at the tip
  
• Mature fruit is brownish long thin capsules about 15"-30" in length, arranged in spiral clusters
  
• Wind dispersed seeds

High Risk Traits:

• Thrives in tropical climates
  
• Elevation range exceeds 1000 m
  
• Naturalized on Hawaii island, as well as parts of west Africa
  
• Root competition and shade can be detrimental to crops
  
• Tolerates many soil types
  
• Shade tolerant (a pioneer species capable of establishing in shade)
  
• Produces wind-dispersed seeds
  
• Can become mature in two years
  
• Coppices readily

Low Risk Traits:

• Unarmed (No spines, thorns, or burrs)
  
• Non-toxic
  
• Ornamental
  
• Does not spread vegetatively