knotweed —  Polygonum aviculare {buckwheat family — Polygonaceae}
Flora of the Yukon Territory, Cody, p. 246b
 { 1/100 sec, f5.6} – {Hillcrest, Whitehorse, Yukon} – {25/07/06 Tuesday, July 25, 2006; 1:38:59 PM}