Ecological Risk Screening Summary - Claspingleaf Pondweed (Potamogeton perfoliatus) - Uncertain Risk

Potamogeton perfoliatus, Claspingleaf Pondweed, is a submerged, rooted, flowering aquatic plant that is native to most of Europe, Asia, the Mediterranean, Guatemala, the northeastern and southeastern United States, and eastern Canada. P. perfoliatus occurs in temperate climates and has a broad tolerance for different growing conditions. This species has been found in use in both
the nursery and aquarium trades. No species-specific regulations on possession or trade were found for P. perfoliatus in the United States. P. perfoliatus was introduced to New Zealand in the late twentieth century but it is unclear whether the species became established in the wild; it has now been intentionally eradicated from New Zealand. The History of Invasiveness for Potamogeton perfoliatus is classified as No Known Nonnative Population. The climate matching analysis to the contiguous United States indicates establishment concern for this species outside its native range. The climate match was high across the contiguous United States except for very limited areas of low match along the Pacific coast. The Certainty of Assessment is classified as Low due to lack of information on the impact of nonnative populations. The Overall Risk Assessment Category for Potamogeton perfoliatus in the contiguous United States is Uncertain.

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.