Family: Asteraceae
High Risk Traits:
- Broad climate suitability
- Naturalized on Kauai, Oahu, Molokai, Maui and Hawaii (Hawaiian Islands), and widely naturalized elsewhere
- A disturbance-adapted weed that can impact agriculture and the natural environment
- Other Ambrosia species are invasive
- Achenes with small, sharp spines
- Allelopathic
- Potentially toxic to browsing and grazing animals
- Highly allergenic pollen, and may cause contact dermatitis
- Tolerates shade (but thrives in full sun)
- Tolerates many soil types
- Able to form dense stands that may exclude other vegetation and reduce species richness
- Reproduces through prolific seed production
- Hybridizes with other Ambrosia species
- Autogamous
- Reaches maturity in <1 year
- Seeds dispersed as a contaminant of crops and bird seed, via agricultural machines, vehicles and soil movement, by water, and internally and externally by birds and other animals
- Capable of forming a persistent seed bank (up to 40 years)
- Tolerates mowing, trampling and grazing
Low Risk Traits:
- Primarily a weed of disturbance and roadsides in the Hawaiian Islands
- Palatable to goats and cattle, despite potential toxicity
- Not reported to spread vegetatively
- Herbicides can provide effective control