Family: Asteraceae
Verbesina encelioides (golden crown-beard) is a taprooted annual herb native to Mexico and southwestern United States. It has become widely naturalized around the world, including the main and northwestern Hawaiian Islands where it is relatively common in dry, disturbed sites, from sea level 0 to 2,805 m (>9200 feet) elevation. Its seeds are dispersed by wind, as a contaminant of other crops, and attached to fur, clothing or equipment. Where invasive, it has impacted both crops and the natural environment, and has reduced habitat for ground nesting birds and native plants in the Norhtwestern Hawaiian Islands.
High Risk Traits:
- Broad climate suitability. Elevation range exceeds 1000 m, demonstrating environmental versatility
- Thrives in tropical climates
- Widely naturalized
- Disturbance-adapted
- Agricultural weed
- Environmental weed
- Other Verbesina species have become invasive
- Toxic to livestock
- Host of crop pathogens
- Tolerates many soil types
- Forms dense stands that can exclude other vegetation
- Reproduces by seed
- Self-compatible
- Able to reach maturity in <1 year (annual)
- Seeds dispersed by wind, and by attachment to animals, clothing and as a soil or seed contaminant
- Seed bank may persist beyond 1 year
Low Risk Traits:
- Unarmed (no spines, thorns or burrs)
- Grows in full sun (Shade-intolerant)
- Not reported to spread vegetatively
- Herbicides may provide effective control
- Burning and mechanical control may also be effective
