Family: Cannabaceae
An invasive tree that is native to Asia. Trema orientalis, commonly known as the gunpowder tree, was introduced to Hawai’i before 1870. Historically, the wood was used for fireworks and gun powder, hence the common name. Thirty-one thousand trees were planted throughout the island chain, starting in 1925. A weed on all the main islands, gunpowder seems to favor the wet sides at lower elevations. The tree is fast growing reaching reproductive maturity in 2 to 3 years. It can grow from vegetative cuttings and by seed. Birds eat the fruit and are a significant disperser of its seeds. It quickly colonized disturbed areas, even with poor soil. It has an extensive root system that helps the tree in times of drought; unfortunately, that root system often grows into septic pipes, ruining the flow of the system.
Description and Dispersal:
- A tree growing up to 100 feet with slightly buttressed roots or swollen base
- Green leaves are alternately arranged, are ovate, are hairy, and have toothed margins
- Inconspicuous flowers are clustered at leaf nodes in dense bunches
- Bird-dispersed fruit are numerous, small, and black
High Risk Traits:
- Elevation range exceeds 1000 m, demonstrating environmental versatility
- Thrives in tropical climates
- Naturalized on main Hawaiian Islands, Florida and possibly elsewhere
- A weed of disturbed forests and pastures
- A weedy tree of plantations and orchards
- Potentially allelopathic
- Host of pathogens
- Potentially causes eczema when handling
- Tolerates many soil types
- Reproduces by seeds
- Fast growth rate
- Seeds dispersed by birds and intentionally by people
- Coppices vigorously
Low Risk Traits:
- Unarmed (no spines, thorns, or burrs)
- Palatable to browsing and grazing animals
- Medicinal, edible, and other uses
- Not reported to spread vegetatively
- Herbicides may provide effective control
