Anemone x lipsiensis is a naturally occurring hybrid of A. nemorosa, the wood anemone, and A. ranunculoides, the yellow wood anemone, that occurs where the ranges of these two species overlap in Europe. The result is a plant with lovely soft yellow flowers. 'Sioux' has larger flowers in a gentle, creamy yellow atop dark foliage. It will go dormant in mid to late summer.