Family: Montiaceae

Cistanthe grandiflora (syn. Calandrinia spectabilis), commonly known as rock purslane, is a showy flowering plant native to Chile. It is best known for its large, vibrant magenta-pink flowers with bright yellow centers, which open in full sun and are especially striking in dry, rocky landscapes. Although often grown as a low, shrubby perennial or subshrub rather than a true tree, rock purslane is popular in gardens for its drought tolerance, long blooming season, and ability to thrive in poor, well-drained soils. It is widely used as an ornamental in xeriscaping, coastal gardens, and containers, where it adds vivid color with relatively low maintenance.

At present, Cistanthe grandiflora is not considered a significant invasive threat in Hawaiʻi. It generally spreads slowly, is most successful in cultivated or disturbed settings, and does not aggressively displace native vegetation. However, like many hardy ornamentals adapted to dry conditions, it can persist outside of gardens if conditions are favorable. Continued monitoring is recommended to ensure it does not expand into natural areas, especially in dry or rocky habitats, and gardeners are encouraged to practice responsible planting and disposal to minimize any potential risk.

High Risk Traits:

• Other Calandrinia species are invasive weeds
  
• Reproduces by seeds and spreads vegetatively
  
• Intentionally spread by people
  
• Seeds lack specific adaptations for dispersal, but small size may facilitate dispersal
  
• Limited ecological information reduces accuracy of risk prediction

Low Risk Traits:

• No reports of invasiveness or naturalization
  
• Unarmed (no spines, thorns, or burrs)
  
• Non-toxic
  
• Ornamental