Anemonella Spach is a genus in the Ranunculaceae family with one species.
Anemonella thalictroides (L.) Spach. is a woodland plant with tuberous roots that flowers in the spring. It is native from southeastern Canada to north central and eastern United States. The first three photos were taken by John Lonsdale of this species.
The photos below, also taken by John Lonsdale are of named cultivars.
A. t. 'Betty Blake', A. t. 'Don Hackenberry', A. t. 'Grand Ridge', A. t. 'Green Dragon', A. t. 'Scoaffs Double'