Family: Acanthaceae
Barleria prionitis, also known as porcupine-flower, is a spiny shrub native to parts of Africa and Asia. It’s grown in some regions for its bright yellow flowers, but the plant’s stiff, sharp spines and fast-growing nature can quickly make it a problem in warm climates. Once established, it forms dense, tangled thickets that outcompete surrounding vegetation and make areas difficult to walk through or maintain. In places where it has escaped cultivation, Barleria prionitis has shown an ability to spread aggressively, especially in disturbed or open areas.
Although not currently naturalized in Hawaiʻi, this species poses a real concern because of its ability to spread by both seeds and vegetative growth. Its spines also create safety hazards for people and pets. Although its flowers may be appealing, Barleria prionitis is not recommended for planting in the islands due to its invasive tendencies and the potential for serious environmental and management impacts. Gardeners can help protect Hawaiʻi’s landscapes by choosing non-invasive, locally appropriate alternatives instead.
High Risk Traits:
- Naturalized beyond native range
- Garden/amenity/disturbance weed
- Environmental weed
- Congeneric weed
- Produces spines or thorns
- Shade tolerant
- Tolerates wide soil range
- Forms dense thickets
- Produces viable seed
- Reproduces vegetatively
- Unintentionally dispersed by people
- Intentionally planted by people
- Water-dispersed propagules
- Persistent seed bank
- Tolerates mutilation
Low Risk Traits:
- Not toxic to humans
- Not wind or animal dispersed
- Seeds don't survive gut passage
- Not a prolific seed producer
- Controlled by herbicides
