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.
Ludwigia adscendens, the Water Primrose, is an aquatic plant native to tropical and subtropical areas in Mexico, sub-Saharan Africa, southern and southeastern Asia, and northern Australia. L. adscendens is used locally as a food source and medicinal plant, potentially used as an ornamental plant, and also has potential for bioremediation of polluted water resources. It is also considered a major weed in some rice-growing areas where it is native, and has the potential to restrict waterways. L. adscendens has been reported as introduced to Bangladesh, the Comoros Islands, Egypt, Madagascar, Pakistan, Singapore, Senegal, and Sri Lanka, and seems to be established in Egypt. Information regarding negative impacts was either available for the Ludwigia genus as a whole or reported from areas that may or may not be outside the native range. Reported impacts beyond the weed concerns mentioned include reductions in oxygen in water bodies, posing a danger to cattle if ingested, and acting as a natural host for Cuscuta sp., a parasite of agricultural crops. Therefore, the history of invasiveness is Data Deficient. The overall climate match for the contiguous United States is High for L. adscendens, with the highest matches found in along the southern United States border and in the Southeast. The certainty of assessment for this species is Low due to ambiguity in taxonomic classification and native range, as well as a lack of well documented information on impacts of introduction. The overall risk assessment category for Ludwigia adscendens is Uncertain.
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Uncertain Risk
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