Hairy Clematis, a native species, has been added to the USWildflowers database (06/07/2012.) Scientific name is Clematis hirsutissima.  Photo below was taken in the Ponderosa State Park, Valley County, ID on May 31, 2012. Go to the Hairy Clematis detail page for more information.

Vase-flower, Sugarbowl, Leather-flower, Hairy Clematis – Clematis hirsutissima