Species that are considered high risk have a well-documented history of invasiveness in at least one location globally, and a high or medium climate match to the contiguous United States.
Glyceria maxima is a wetland plant native to Eurasia and has become established in a number of countries around the world. G. maxima has broad climate suitability and prolific reproductive output. The history of invasiveness is high. The plant has been introduced as grazing forage for livestock but has also caused livestock deaths in Australia. This species directly impacts a native species of concern in New Zealand by destroying the microhabitat needed for successful reproduction. Monocultures of G. maxima have negative impacts on insect and bird diversity and ecosystem services. The climate match for the contiguous United States is high with only four states that did not have individually high climate scores. The certainty of assessment is high. The overall risk assessment category is high.
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High Risk
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