Family: Asteraceae
High Risk Traits:
- Broad climate suitability
- Able to grow and spread in regions with tropical climates
- Widely naturalized (although no evidence in the Hawaiian Islands to date)
- A disturbance weed that can negatively impact agriculture
- Other species are invasive
- Allergenic to people, and toxic if consumed in large quantities
- Shade tolerant
- Tolerates many soil types
- Forms dense stands in disturbed habitats or overgrazed pastures
- Reproduces by seeds
- Reaches maturity in 2 growing seasons
- Dispersed by wind, water and intentionally by people
- Prolific seed production
- Seeds can remain viable in the soil for up to 4 years
Low Risk Traits:
- Unarmed (no spines, thorns, or burrs)
- Palatable to some grazing animals (despite reports of possible toxicity)
- Herbicides may provide effective control
- Killed by fire