common water-milfoil —  Myriophyllum sibiricum {water-milfoil family — Haloragaceae}
Flora of the Yukon Territory, Cody, p. 448a
 { 1/25 sec, f8.0} – {Hidden lakes, Whitehorse, Yukon} – {30/07/08 Wednesday, July 30, 2008; 6:33:01 PM}