Celandine poppy or Wood poppy (Stylophorum diphyllum)

Member of the Papaveraceae (Poppy) family.  Growing in damp woods, 10 - 16 inches, March through May.  The flower is yellow with 4 fragile, round petals and has paired pale, deeply lobed stem leaves with a whitish bloom on the underside.  The seed pod is ovoid and hairy.
 
To learn more about Celandine poppy , visit its profile at the USDA Plants Database