Family: Euphorbiaceae
Origin, Description & Uses:
Macaranga tanarius, commonly known as the parasol leaf tree, is native to tropical and subtropical Asia through the western Pacific. It is a fast-growing, small to medium-sized tree recognized for its large, round, shield-like leaves that resemble a parasol. The tree produces small flowers and distinctive capsule-like fruits, and it often thrives in disturbed areas, forest edges, and open landscapes. Because of its rapid growth and broad canopy, it is sometimes planted for shade, erosion control, and as an ornamental. In parts of its native range, it has also been used in traditional practices and for lightweight timber.
Risks & Threats:
In Hawaiʻi, Macaranga tanarius is naturalized on Kauaʻi, Oʻahu, Maui, and Hawaiʻi Island. This species possesses traits that are cause for concern, including rapid growth, prolific seed production, and the ability to colonize disturbed habitats quickly. It can form dense stands that outcompete native vegetation and alter natural successional processes, potentially impacting biodiversity and ecosystem function in tropical island environments. Due to these risks, it could detrimentally impact Hawaiʻi’s ecosystems. It is recommended to choose a low-risk or native alternative when suitable options are available for landscaping or restoration projects.
High Risk Traits:
- Naturalized in Hawaii (Kauai, Oahu, Maui)
- Forms dense thickets
- Broad climate & soil tolerance
- Produces viable seeds
- Bird-dispersed (endozoochory)
- Animal-dispersed externally (spiny capsules)
- Intentionally spread by people (ornamental, reforestation)
- Congeneric weed (M. mappa invasive)
- Fire-tolerant
- Fast-growing pioneer
- Produces spine-like structures on fruits
Low Risk Traits:
- Not toxic to humans or animals
- Used as fodder
- No agricultural/forestry weed status
- No vegetative reproduction
- No seed productivity data (>1000/m²)
- Not self-compatible (dioecious)
- Not wind-dispersed
- No produce contamination evidence
