Ribbonleaf Pondweed, Ribbon-leaf Pondweed, Ribbon-leaved Pondweed
Potamogeton epihydrus
Synonyms: Potamogeton epihydrus ssp. nuttallii, Potamogeton epihydrus var. ramosus
Ribbonleaf pondweed floating on the surface of Sparks Lake at the boat launch, Deschutes National Forest.........September 5, 2014. The difference between the floating and submerged leaves is clearly evident in the photo.
The photo above shows a close-up of ribbonleaf pondweed as seen in one of the slow-draining pools in Swampy Meadows on the western slopes of Mt. Adams.....................September 6, 2008. The submerged stem leaves are much different in shape than the floating leaves as seen here. The submerged stem leaves are long, narrow (but greater than 2 mm) and have a prominent midvein which runs their length (barely visible here).
The photo above shows a close-up of the floating leaves of ribbonleaf pondweed as seen in Swampy Meadows on the western slopes of Mt. Adams.....................September 6, 2008.
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Close-ups of the floating leaves of ribbonleaf pondweed as seen in Swampy Meadows on the western slopes of Mt. Adams.....................September 6, 2008.
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Ribbonleaf pondweed as seen in a shallow pond in upper Muddy Meadows south of the Muddy Meadows trail................August 28, 2012. Note the long, narrow submerged leaves and the broader floating leaves.
Paul Slichter