All Ranunculus (buttercup) species are poisonous when eaten fresh, but their acrid taste and the blistering of the mouth caused by their poison means they are usually left uneaten.
Buttercup, genus of about 300 species of herbaceous flowering plants in the family Ranunculaceae. Buttercups are distributed nearly worldwide and are especially common in woods and fields of the north temperate zone. Several are cultivated as ornamentals and for the floral industry.
Ranunculus or buttercup flowers are cool-season perennial tubers characterized by their layers of paper-thin petals. Because of their dainty appeal, these blooms have always been a favorite in many wedding bouquets and floral arrangements.