Swamp Buttercup

Ranunculus hispidus - commonly known as swamp buttercup. 

A perennial native it likes shaded bottom land.  It's growing all over the place along the creek 

That's it in the center of the picture.  Better yet - it's surrounded by native, blue flag iris.

The wild iris is a very showy wildflower.  I'll post pictures of that as soon as it blooms.

click on image to enlarge