Miner’s Lettuce, a native species, has been added to the USWildflowers database (07/25/2010.)  Scientific name is Claytonia perfoliata.  This plant also is known by the common names Indian Lettuce and Winter Purslane.  Photo below was taken in the Boise National Forest near Boise, ID, on 06/15/2010.

Miner's Lettuce - Claytonia perfoliata