Family: Asteraceae
Osteospermum moniliferum (commonly known as boneseed or bitou bush) is a fast-growing, woody shrub native to South Africa. It was originally introduced to many regions, including Hawaii, Australia, and New Zealand, for ornamental purposes and to help stabilize coastal dunes and disturbed soils. The plant is characterized by its bright yellow, daisy-like flowers and fleshy, black berries. Historically, its rapid growth and soil-binding ability made it seem like a useful species for erosion control in coastal areas.
Despite its initial uses, this species is now a serious environmental weed in many places. It invades coastal ecosystems, dunes, and open woodlands, where it forms dense, smothering thickets that crowd out native plants and reduce biodiversity. Its high-risk traits include producing thousands of viable seeds that are spread by birds, water, and human activity, forming a long-lived seed bank, and being allelopathic (releasing chemicals that inhibit other plants). It also increases fire risk, tolerates poor soils, and resists many control methods. Effective management requires early detection, persistent removal, and preventing its spread to protect native habitats. It is not currently known to be present in the Hawaiian Islands.
High Risk Traits:
- Broad climate suitability
- Naturalized beyond native range
- Environmental weed
- Allelopathic
- Creates fire hazard
- Tolerates varied soils
- Forms dense thickets
- Produces viable seeds
- Hybridizes naturally
- Multiple dispersal vectors (unintentional, human, water, bird, animal)
- Seeds survive gut passage
- Prolific seed production (>1000/m²)
- Persistent seed bank (>1 year)
- Tolerates disturbance (fire, cultivation)
- Poorly controlled by herbicides
Low Risk Traits:
- No spines/thorns/burrs
- Palatable to grazers
- Not toxic to animals or humans
- Not shade tolerant
- Not self-compatible
- No vegetative reproduction
- No wind or produce-contaminant dispersal
