Family: Apocynaceae

Origin, Description & Uses
Pentalinon luteum (wild allamanda) is native to southern Florida and the wider Caribbean region, where it grows in coastal thickets, dry forests, and scrub habitats. It is a vigorous, twining woody vine in the dogbane family (Apocynaceae), recognized for its glossy green foliage and bright, showy yellow trumpet-shaped flowers. In landscaping, it is sometimes used as an ornamental vine for fences, trellises, and naturalistic plantings due to its attractive blooms, tolerance of heat and drought, and ability to thrive in sandy, nutrient-poor soils.

Risks & Threats
Although Pentalinon luteum is currently not known to be naturalized in the Hawaiian Islands, it possesses traits that raise concern for tropical island ecosystems. It is a fast-growing, climbing vine that can smother and outcompete nearby vegetation by overtopping shrubs and small trees, potentially altering habitat structure. Like many members of the Apocynaceae family, it contains milky latex that may be toxic if ingested, reducing its palatability to herbivores and contributing to its persistence once established. In suitable climates, it may spread beyond cultivation through seed dispersal and vegetative growth. Given these characteristics, caution is warranted, and planting should be avoided where possible. When available, choosing a low-risk or native alternative is strongly recommended to help protect Hawaiʻi’s unique ecosystems.

High Risk Traits:

• Tropical/subtropical climate suitability
  
• Toxic to animals (cattle) and humans (skin/ingestion)
  
• Unpalatable to grazers
  
• Shade tolerant
  
• Wide soil tolerance (sand to clay, acidic to alkaline)
  
• Climbing/smothering vine
  
• Forms tuberous roots
  
• Wind-dispersed seeds
  
• Benefits from pruning (aggressive spread)

Low Risk Traits:

• Not naturalized
  
• No spines, thorns, or burrs
  
• No allelopathy
  
• No vegetative spread
  
• No persistent seed bank