Upland Yellow Violet, a native species, has been added to the USWildflowers database (05/23/2012.) Scientific name is Viola praemorsa.  Photo below was taken in the Boise Foothills of Ada County, ID on June 10, 2011.   It  is also known by the common names Canary Violet, Astoria Violet, Prairie Violet, Yellow Montane Violet, and Wavyleaf Violet.  Go to the Upland Yellow Violet detail page for more information.

NOTE: Nov 22, 2013 – R. John Little, Ph.D., noted expert on Violaceae, has identified this as Viola purpurea subsp. venosa rather than Viola praemorsa. — gcw

Upland Yellow Violet, Canary Violet, Astoria Violet, Prairie Violet, Yellow montane violet, Wavyleaf Violet – Viola praemorsa