Family: Apocynaceae

Origin, Description & Uses
Pachypodium densiflorum (commonly known as Madagascar palm) is a striking succulent species native to central Madagascar, where it grows in rocky, dry habitats. Despite its common name, it is not a true palm but belongs to a group of drought-adapted plants with thick, water-storing trunks and clusters of sharp spines. The plant is valued in cultivation for its sculptural form, silver-green stems, and bright yellow, fragrant flowers that appear seasonally. It is often grown as an ornamental container plant or in xeriscape and dry gardens, where its unique appearance adds architectural interest and requires relatively little water once established.

Risks & Threats
This species is considered low risk and is not known to be invasive or naturalized in Hawaiʻi. Its slow growth and specialized habitat requirements make it unlikely to spread aggressively in local ecosystems. In cultivation, the main concerns are related to its sharp spines, which can cause injury if handled carelessly, and its sensitivity to excess moisture, which can lead to rot in wet environments. Overall, Pachypodium densiflorum can be a safe ornamental choice when grown responsibly in appropriate conditions.

High Risk Traits:

• Grows in tropical climates
  
• Spiny
  
• Toxic
  
• Reproduces by seeds
  
• Reaches maturity in 2 years
  
• Seeds likely dispersed by wind and people
  
• Able to regenerate after cutting

Low Risk Traits:

• No reports of invasiveness or naturalization, but limited evidence of widespread introduction outside native range
  
• Landscaping and ornamental value
  
• Specialized pollinator requirements (likely limits seed set outside native range)
  
• Not reported to spread vegetatively