Looks like some species of Ranunculus (buttercup) genus.

On 15 Jun 2003 08:30:25 -0600, (David Hamilton Cox)
wrote:

There are six pictures of this tiny flower, taken on June 6 in Shenandoah
National Park, at http://www.nyx.net/~dhcox/park, the last six in the
list on that page. This was in the same area as the alumroot I asked about
earlier, a rocky slope, western facing, about 2000 ft. elevation. I have
no idea what this is and would appreciate any ideas, guesses as to family,
etc. Thanks!

(the flower is about 1/4 inch in diameter or less; wide variety of leaf
types on the plant, as can be seen in the pictures; plant about 6 to 8
inches tall.)

-David Cox