Species that are considered uncertain risk need a more in-depth assessment beyond the Risk Summary to better define the species’ risk to U.S. environments.
Dotted duckweed (Spirodela punctata) is a small flowering, floating aquatic plant. It is native to Australia and Southeast Asia. S. punctata can be found in the aquarium and water garden trade, is used to treat wastewater, and is being investigated as a source of biofuel. The history of invasiveness is classified as Data Deficient. There are many records of introductions and establishment along with cryptogenic occurrence records for many countries. S. punctata is established in over half of the States in the United States. S. punctata is a regulated species in Texas. A few general statements of negative impact after introduction were found. One peer-reviewed paper with an English abstract was found that suggested impacts from S. punctata may be minimal. The overall climate match is High. Most areas of the contiguous United States had high climate matches except for the Great Plains, upper Midwest, and some patches in the northwest. The certainty of assessment is Low due to a lack of scientifically defensible impact information. Information is available but there is some contradiction in describing the geographic range of the species. The overall risk assessment is Uncertain.
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Uncertain Risk
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