Wetland Plants of Wisconsin
|Potamogeton epihydrus Raf.
pondweed has both broader, elliptical floating leaves and long, narrow
ribbon-like submersed leaves. The submersed leaves usually have a broad
stripe of lighter colored tissue along the midrib. The bases of the floating
leaves are tapered to the petiole, unlike the heart-shaped bases of the
very common P. natans.. In deeper water or in flowing water the
floating leaves of P. epihydrus may not develop, leaving only the
long ribbon-like submersed leaves, which can still be recognized by the
broad, light mid-stripe and the width of the leaves (usually >5 mm).
Ribbon-leaf pondweed is found throughout Wisconsin in a variety of lakes and streams, mostly in shallow water. It is more common in the north. Botanists recognize about 25 species of pondweeds in Wisconsin and some species can be very difficult to distinguish. A good key, good specimens and considerable practice are required to make accurate identifications.