Family: Polygonaceae
High Risk Traits:
- Elevation range exceeds 1000 m, demonstrating environmental versatility
- Grows in tropical climates
- Naturalized on Oahu, Molokai, Maui, and Hawaii (Hawaiian Islands), Australia, and elsewhere
- A disturbance-adapted weed that impacts agriculture and potentially the natural environment
- Other Emex species are invasive
- Spine-tipped achenes
- Allelopathic
- Tolerates many soil types
- Capable of forming dense cover in disturbed habitats
- Reproduces by seeds
- Hybridizes with Emex australis
- Self-compatible
- Reaches maturity in one growing season (annual)
- Seeds dispersed by sticking to animals and vehicles, by wind, water and as a seed contaminant
- Prolific seed production
- Might form a persistent seed bank (based on traits of related taxon)
Low Risk Traits:
- Thrives in open, disturbed habitats (may be shade intolerant)
- Not reported to spread vegetatively
- Herbicides and mechanical methods have provided effective control
- Biocontrol agents have been introduced into the Hawaiian Islands