white-stemmed pondweed —  Potamogeton praelongus {pondweed family — Potamogetonaceae}
Flora of the Yukon Territory, Cody, p. 058b
 { 1/40 sec, f9.0} – {Hidden lakes, Whitehorse, Yukon} – {20/08/08 Wednesday, August 20, 2008; 2:01:53 PM}