Family: Gunneraceae
High Risk Traits:
- Elevation range exceeds 1000 m, demonstrating environmental versatility
- Native to and naturalized in regions with a temperate and Mediterranean climate (could threaten upper elevations of tropical and subtropical islands)
- Naturalized in the Azores, New Zealand, Ireland, the UK, France, and California (but no evidence in the Hawaiian Islands to date)
- An environmental weed in New Zealand and Ireland, reducing native biodiversity
- Gunnera manicata is also invasive
- Leaves covered with stiff prickles
- Shade-tolerant
- Tolerates many soil types
- Forms dense stands that exclude other vegetation
- N-fixing (may alter soil chemistry)
- Reproduces by seeds and vegetatively by rhizomes (able to spread by rhizome fragments)
- Seeds dispersed by birds, water, as a soil contaminant and intentionally by people
- Rhizome fragments also moved by water
- Prolific seed production
- Seeds may form a persistent seed bank (reports from New Zealand suggest no seed bank is formed, but UK evidence suggests yes)
- Able to resprout after cutting
Low Risk Traits:
- Climate preferences may limit invasiveness to upper elevations of tropical islands
- Palatable to browsing and grazing animals (does not spread into pastures with livestock)
- Reaches maturity in 4-5 years (but may be able to spread vegetatively at an earlier age)
- Herbicides may provide effective control
