Family: Asteraceae
Origin, Description & Uses
Gazania rigens, commonly known as gazania or treasure flower, is a low-growing, perennial herb native to southern Africa. It is widely cultivated for its bright, daisy-like flowers that come in vivid shades of yellow, orange, pink, and red, often with striking patterns. The plant thrives in sunny, dry conditions and is frequently used as a groundcover, in borders, and for erosion control due to its drought tolerance and ability to spread quickly. Its attractive blooms and hardiness have made it a popular ornamental plant in many warm climates, including Hawaiʻi.
Risks & Threats
However, Gazania rigens is naturalized on Maui and is considered a high-risk species. It spreads aggressively through both seeds and creeping stems, allowing it to form dense mats that can outcompete native vegetation and alter natural plant communities. This species possesses traits that are cause for concern, including rapid growth, tolerance of poor soils, and adaptability to coastal and disturbed environments. These characteristics enable it to potentially detrimentally impact tropical island ecosystems by reducing biodiversity and displacing native species. Due to these risks, it is recommended to avoid planting gazania and instead choose a low-risk or native alternative better suited to Hawaiʻi’s unique environment.
High Risk Traits:
- Naturalized in Australia, California, and Hawaiʻi (Kēōkea)
- Invasive in Tasmania, Queensland, NSW, and California
- Spreads by wind, water, and dumped garden waste
- Vegetative reproduction via creeping, rooting stems
- Intentional planting as an ornamental
- High seed production (~125,000 seeds/lb) with self-seeding
- Tolerates poor, sandy, saline, and drought-prone soils
- Fast generation time (flowers within one year)
Low Risk Traits:
- Not a weed in agricultural or forestry settings
- No physical defenses (no spines, thorns, or burrs)
- Non-toxic to animals and humans
- Not shade tolerant
- No persistent seed bank (germinates quickly)
