Rue Anemone
Latin name: Anemonella thalictroides
Member of the Buttercup family (Ranunculaceae)
This is a delicate plant with 2 or 3 flowers on slender stalks above a whorl of small 3-lobed leaves. The 6 petals (sometimes 8 or 10) are really sepals. It grows to a height of 4 to 8 inches. It is found mainly in woods. It blooms between March and May.
Source:
"A Field Guide to Wildflowers, Northeastern and North-central North America" by Roger Tory
Peterson and Margaret McKenny
Photo taken near Holston River