trembling aspen —  Populus tremuloides {willow family — Salicaceae}
Flora of the Yukon Territory, Cody, p. 213a
 { 1/250 sec, f4.0} – {McIntyre Ck. college, Whitehorse, Yukon} – {15/08/09 Saturday, August 15, 2009; 4:18:31 PM}