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.
Large grey willow (Salix cinerea) is a woody shrub native to Eurasia. It requires moist soil conditions but can tolerate extended cold temperatures. The bark has been used for medicinal purposes. The history of invasiveness is classified as high. S. cinerea has been introduced to and become established in Canada, the United States, Australia, and New Zealand. The species was introduced to prevent erosion. Impacts of invasion include excluding native plant species, alteration of invertebrate communities, alteration of organic matter deposition, and reductions in surface water availability. Climate matching indicated the contiguous United States has a high climate match. The eastern portion of the country had the largest area of high match and already contains established populations of S. cinerea. Certainty of this assessment is medium. The overall risk assessment category is high.
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High Risk
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