water smartweed —  Polygonum amphibium laevimarginatum {buckwheat family — Polygonaceae}
Flora of the Yukon Territory, Cody, p. 246a
 { 1/60 sec, f5.6} – {Paddys Pond/Ice Lake, Whitehorse, Yukon} – {31/07/06 Monday, July 31, 2006; 3:53:01 PM}