Family: Acanthaceae

Origin, Description & Uses
Odontonema cuspidatum (fire spike) is a flowering shrub native to Central America, ranging from southern Mexico to Honduras. It is commonly grown as an ornamental plant in tropical and subtropical landscapes due to its striking upright clusters of bright red tubular flowers and attractive evergreen foliage. Fire spike is valued in gardens and hedges for its long blooming period and ability to attract hummingbirds, butterflies, and other pollinators. It tolerates partial shade and a variety of soil conditions, making it a popular choice for tropical landscaping.

Risks & Threats
Fire spike is widely naturalized across the Hawaiian Islands, including Kauaʻi, Oʻahu, Maui, and Hawaiʻi Island. In disturbed areas and favorable conditions, it can spread beyond cultivation and form persistent populations. This species possesses traits of concern such as vigorous growth, effective vegetative spread, and tolerance of a range of environments, which may allow it to compete with and displace native understory plants. As a result, it could detrimentally impact tropical island ecosystems by reducing native biodiversity and altering habitat structure. When possible, choosing low-risk or native Hawaiian plants as alternatives is recommended to help protect local ecosystems.

High Risk Traits:

• Broad climate tolerance (sea level to 1,900 m; zones 8–11)
  
• Native to tropics; already naturalized in Hawaii, Puerto Rico, Florida, Tahiti, Samoa
  
• Repeated introductions as ornamental
  
• Forms dense monospecific stands
  
• Shade tolerant
  
• Wide soil tolerance (except salt)
  
• Reproduces vegetatively (root suckers, layering)
  
• Blooms in first year; fast growth
  
• Spreads via water, garden waste, and intentional planting
  
• Tolerates pruning and recovers quickly after frost

Low Risk Traits:

• No spines, thorns, or burrs
  
• No evidence of allelopathy, parasitism, or toxicity to animals
  
• Not a weed of agriculture or forestry
  
• Low seed viability (1% germination)
  
• Requires specialist pollinators (hummingbirds)
  
• Not wind-, bird-, or animal-dispersed
  
• Not a prolific seed producer