Family: Phytolaccaeae

Origin, Description & Uses
Rivina humilis (coral berry, rouge plant) is native to Tropical and Subtropical America, where it grows in a variety of forest edges, thickets, and disturbed habitats. It is a small, shade-tolerant understory shrub typically reaching about 1–3 feet in height. The plant produces slender stems, light green leaves, and delicate sprays of tiny white flowers followed by bright red berries that are highly ornamental. In some regions, it has been used as an informal decorative plant in shade gardens and landscapes, valued for its colorful fruit display and ability to grow in low-light conditions.

Risks & Threats
In Hawaiʻi, Rivina humilis is already naturalized on Kauaʻi, Oʻahu, Molokaʻi, Maui, and Hawaiʻi Island, where it persists in dry to mesic, shaded, disturbed areas from low elevations (10–130 m). This species possesses traits that are cause for concern, including shade tolerance, prolific berry production that attracts birds, and the ability to spread into understory habitats. These characteristics allow it to establish and expand in sensitive ecosystems, where it can compete with native understory vegetation and alter habitat structure. As a naturalized species, it could detrimentally impact tropical island ecosystems by contributing to the gradual displacement of native plants in forest understories and disturbed sites. Choosing low-risk or native alternatives is recommended when available. Where it is already present and widespread, managing or avoiding its use in new plantings—especially near natural or semi-natural areas—can help reduce further spread and ecological impacts.

High Risk Traits:

• Naturalized beyond native range, including Hawaii, Fiji, Tonga, and Australia
  
• An environmental weed in Australia, including national parks
  
• Shade tolerant
  
• Tolerates wide range of soil types (sand, loam, clay, calcareous) and pH (acidic to alkaline)
  
• Grows in diverse climates (USDA zones 7a–10b)
  
• Produces viable seeds
  
• Self-compatible
  
• Dispersed intentionally as an ornamental
  
• Bird-dispersed seeds
  
• Seeds survive passage through bird guts
  
• Prolific seed production (up to ~10,000 seedlings/m²)
  
• Forms a persistent seed bank (up to ~4 years)
  
• Toxic to humans (leaves, roots; fruit causes numbness, vomiting)
  
• Tolerates herbicides (requires re-treatment)

Low Risk Traits:

• No spines, thorns, or burrs