Amazing Flower

I have seen this flower on previous hikes but this year it is very prevalent on the forest floor. It has been blooming for about 3 days now. Does anyone know what it is?

In this view, the blossoms are wide open.
Early in the day with low light and cool air,
the blossoms were contracted in a defensive appearance.
UPDATE: This flower is a "trout lily" or  Erythronium americanum.