A field of yellow buttercups.
buttercup definition by Webster's New World
Webster's New World College Dictionary Copyright © 2010 by Wiley Publishing, Inc., Cleveland, Ohio. Used by arrangement with John Wiley & Sons, Inc.
designating a large, widespread family (Ranunculaceae, order Ranunculales) of dicotyledonous flowering plants, including peonies, aconites, and anemones
any of a genus (Ranunculus) of normally yellow-flowered plants of the buttercup family, common in meadows and wet places
buttercup definition by American Heritage Dictionary
Any of numerous herbs of the genus Ranunculus, native chiefly to temperate and cold regions and having acrid juice, often toothed or lobed leaves, and usually yellow or white flowers with numerous pistils.