Wikipedia tells me:
"The genus Pulsatilla contains about 33 species of herbaceous perennials native to meadows and prairies of North America, Europe, and Asia. Derived from the Hebrew word for Passover, "pasakh", the common name pasque flower, refers to the Easter flowering period. Common names include pasque flower (or pasqueflower), wind flower, prairie crocus, Easter flower, and meadow anemone. Several species are valued ornamentals because of their finely-dissected leaves, solitary bell-shaped flowers, and plumed seed heads. The showy part of the flower consists of sepals, not petals."
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