Family: Melastomataceae
Origin, Description & Uses
Heteroblemma serpens (syn. Medinilla serpens) is a woody root-climber or creeper native to Borneo (Sarawak, Sabah) and the Riau Archipelago (Natuna Besar). The plant climbs on trees or rocks, reaching heights of 5–7 m, with slender, hairy stems and pale pink to pale red flowers borne in dense fascicles. Its fruits are small ovoid berries (approx. 5 mm) that ripen orange to brown, containing numerous tiny seeds (less than 1 mm). The species is cultivated as an ornamental houseplant or outdoor container plant, sold in nurseries and online for its attractive trailing habit and tropical foliage.
Risks & Threats
Heteroblemma serpens is not currently known to be naturalized in Hawaiʻi, but it possesses several traits of concern. It is shade-tolerant, adapted to tropical limestone habitats, and has a climbing growth habit that could smother vegetation. Its seeds are likely bird-dispersed and may survive gut passage, and the plant is intentionally spread through the horticultural trade. Additionally, related species formerly classified as Medinilla are known to be weedy or invasive elsewhere. Many key risk traits (e.g., herbicide response, seed bank persistence, and fire tolerance) remain unknown, increasing uncertainty. Ongoing evaluation is needed to determine whether it could impact Hawaiʻi, and caution is recommended to ensure that it does not negatively impact Hawaiian ecosystems.
The Hawaii-Pacific Weed Risk Assessment (HPWRA) is a service of the Hawaii Invasive Species Council (HISC).
High Risk Traits:
- Shade tolerant (understory/epiphytic)
- Climbing/smothering growth habit
- Produces viable seed
- Intentionally dispersed by people (ornamental trade)
- Bird-dispersed; propagules likely survive gut passage
- Congeneric weeds exist (formerly Medinilla)
- Many risk traits unknown (uncertainty increases risk)
Low Risk Traits:
- Not naturalized beyond native range (but limited evidence of introduction)
- Not documented as any type of weed (but limited evidence of introduction)
- No spines, thorns, or burrs
- Not toxic to animals or humans
- No fire hazard (succulent)
- Does not form dense thickets
- Not wind-dispersed
