Family: Lamiaceae
Clerodendrum japonicum, commonly known as Japanese glory bower or pagoda flower, is a fast-growing ornamental shrub native to tropical Asia. It is admired for its large, showy clusters of bright red flowers that bloom for much of the year, often attracting butterflies and other pollinators. The plant has broad, heart-shaped leaves and can grow several feet tall, forming dense thickets if left unmanaged. Because of its striking flowers and lush appearance, Japanese glory bower has been widely planted in gardens and landscapes as a decorative accent or hedge plant.
Despite its ornamental appeal, Japanese glory bower poses significant risks in tropical environments like Hawaiʻi. It readily spreads through suckers and vegetative growth, allowing it to escape cultivation and form dense stands that outcompete native plants for light, space, and nutrients. Once established, it can be difficult to control or remove, and infestations may degrade native forests and understory habitats. Due to its aggressive growth and potential to threaten native ecosystems, planting Japanese glory bower is discouraged, and non-invasive alternatives are recommended for landscaping.
High Risk Traits:
- Elevation range exceeds 1000 m, demonstrating environmental versatility
- Thrives in tropical climates
- Naturalized in Bhutan, Mexico, Guyana; Suriname, Brazil, and possibly Georgia and Florida
- Possibly weedy and invasive
- Other Clerodendrum species have become invasive
- Reproduces by seeds and vegetatively by suckers
- Seeds dispersed by birds and intentionally by people
- Able to resprout after cutting to base
- Limited biological and ecological information may reduce accuracy of risk prediction
Low Risk Traits:
- Unarmed (no spines, thorns or burrs)
- Not reported to be toxic
- Ornamental
- May only tolerate partial shade, or thrive in full sun (may limit ability to invade intact forest)
