Buttercup

·noun A plant of the genus Ranunculus, or crowfoot, particularly R. bulbosus, with bright yellow flowers;

— called also butterflower, golden cup, and kingcup. It is the cuckoobud of Shakespeare.

buttercup
n. The familiar English flower isrepresented in Australia and Tasmania by various species of Ranunc...

Dictionary of Australasian Words Phrases and Usages by Edward E. Morris