Family: Apocynaceae

Origin, Description & Uses
Dischidia ovata, commonly known as watermelon dischidia, is a trailing epiphytic vine native to New Guinea and Queensland, Australia. This attractive plant is valued for its small, oval leaves patterned with pale veins that resemble the rind of a watermelon. It thrives in warm, humid conditions and is widely grown as a houseplant, in hanging baskets, or mounted on boards and trees where its stems can cascade gracefully. Its ornamental foliage, compact growth, and suitability for bright, indirect light make it popular with collectors and tropical plant enthusiasts.

Risks & Threats
On Oʻahu, watermelon dischidia is naturalized and does possess traits that are cause for concern. As an epiphyte capable of rooting along its stems and spreading vegetatively, it can establish on trees and other surfaces, potentially forming dense mats that compete with native plants—especially native epiphytes—for space and light. Although it is currently placed in the “Low Risk” category, caution is recommended to ensure that it will not negatively impact Hawaiʻi’s ecosystems. Continued monitoring is advised, and a future revision of the assessment could change the current risk rating if its spread or ecological impacts increase.

High Risk Traits:

• Thrives in tropical climates.
  
• Naturalized on Oʻahu.
  
• Climbing habit (can smother plants).
  
• Shade tolerant.
  
• Increasingly popular ornamental.
  
• Seeds dispersed by ants and wind.
  
• Sap is toxic and can cause skin irritation.

Low Risk Traits:

• Narrow climate tolerance (low elevations, USDA zones 10a-12b).
  
• Not documented as an invasive weed elsewhere.
  
• No congeneric weeds reported.
  
• Lacks spines, thorns, or burrs.
  
• No persistent seed bank (seeds do not store well).