small-flower prairie wallflower —  Erysimum coarctatum {mustard family — Brassicaceae (Cruciferae)}
Flora of the Yukon Territory, Cody, p. 350b
 { 1/100 sec, f4.0} – { , Klondike Hwy, South, Yukon} – {17/08/06 Thursday, August 17, 2006; 10:59:42 AM}